Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition Candyce M. Jack, LVT Sequim, Washington Patricia M. Watson, LVT Redmond, Washington Mark S. Donovan, DVM Consulting Editor Seattle, Washington First Edition first published 2003 Second Edition first published 2008 © 2008, Candyce M. Jack and Patricia M. Watson Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Editorial Office 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book, please see our website at www.wiley.com/wiley-blackwell. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For those organizations that have been granted a photocopy license by CCC, a separate system of payments has been arranged. The fee codes for users of the Transactional Reporting Service are ISBN-13: 978-0-8138-1204-5/2008. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloguing-in-Publication Data Jack, Candyce M. Veterinary technician’s daily reference guide: canine and feline / Candyce M. Jack, Patricia M. Watson; consulting editor, Mark S. Donovan. – 2nd ed. p. ; cm. Rev. ed. of: Veterinary technician’s daily reference guide: canine and feline / Candyce M. Jack, Patricia M. Watson; consulting editor, Mark S. Donovan. C2003. Includes bibliographical references and index. ISBN 978-0-8183-1204-5 (alk, paper) 1. Veterinary medicine–Handbooks, manuals, etc. I. Watson, Patricia M. II. Jack, Candyce M. Veterinary technician’s daily reference guide. III. Title. [DNLM: 1. Veterinary Medicine–methods–Handbooks. 2. Animal Technicians– Handbooks. 3. Cat Diseases–Handbooks. 4. Dog Diseases–Handbooks. SF 748 J12v 2008] SF748.J33 2008 636.089–dc22 2007050954 A catalogue record for this book is available from the U.S. Library of Congress. Set in Berling-Roman by SNP Best-set Typesetter Ltd Printed in Singapore by Markono Print Media Pte Ltd 1 2008 This book is dedicated to all the licensed veterinary technicians who are doing their best for the advancement of the field and devoting themselves to providing the best possible care to their animal patients. A special thanks to our medical editor, Dr. Mark Donovan, for his commitment to our goal and his perseverance to ensure the book presented advanced and accurate information. Patricia Special thanks for family, co-workers, and friends who are consistently supporting me to new levels of learning and opportunity. Each of you and your pets are a part of this book and I am grateful for your constant support. Thanks to my coauthor, whose insight, energy, dedication to the veterinary field, and perseverance has made this second edition a reality. And finally, I dedicate this book in special remembrance of my beloved Einstein (1991–2006), whose teeth are immortalized within the pages of this book. Candyce With heartfelt gratitude, I thank Dede for her patience and friendship, Linda for her continuous support of my endeavors, Megan for teaching me “you can’t push the river,” and, most important, my incredibly supportive family for the sacrifices they have made to allow me to complete this project. Table of Contents Figure List Preface Acknowledgments Contributors xvii xxi xxiii xxiii Section One: Anatomy 3 Chapter 1: 5 Anatomy Anatomy Overall Musculature Skeletal Internal Organs Circulatory System Nervous System Urogenital Eye Ear 6 6 6 7 8 9 10 11 13 13 Section Two: Preventative Care 15 Chapter 2: Preventative Care and Vaccinations 17 Physical Examinations Preliminary Examination Physical Examination Pediatric Physical Examination Normal Parturition Care and Feeding of Orphaned Puppies and Kittens Geriatric Physical Examination Cardiac Examination Pulmonary Examination Abdominal Examination Otoscopic Examination Regional Lymph Node Examination Neurologic Examination Orthopedic Examination Vaccinations Guidelines to Follow When Vaccinating an Animal 18 19 20 23 26 27 28 30 32 33 33 34 34 36 37 37 Chapter 3: Canine Transmissible Diseases Coronavirus, Distemper Hepatitis, Infectious Tracheobronchitis Leptospirosis, Lyme Disease Parvovirus, Rabies Canine Vaccination Protocol Feline Transmissible Diseases Feline Calicivirus Feline Infectious Peritonitis Feline Panleukopenia Virus, Feline Immunodeficiency Virus Feline Leukemia Virus, Feline Rhinotracheitis Virus Feline Vaccination Protocol Animal Care Client Education: Home Dental Care Grooming Bathing Nail Trimming Anal Sac Expression Ear Cleaning and Flushing 38 38 39 41 42 44 44 44 46 47 Nutrition 57 General Nutrition Daily Caloric Requirement Worksheet for a Healthy Animal General Life Stage Feeding Guidelines Body Condition Scoring System Disease Nutritional Requirements Obesity Management 58 49 51 51 52 53 53 54 54 55 59 60 62 64 68 Section Three: Diagnostic Skills 69 Chapter 4: Laboratory 71 Blood Chemistries Blood Collection, Handling, Storage, and Transport Tips 74 74 vii Blood Collection Tubes Blood Chemistries Bone Marrow Evaluation Bone Marrow Collection, Handling, Storage, and Transport Tips Supplies for Bone Marrow Collection Smear Techniques Evaluation Bone Marrow Evaluation Cell Type Identification Interpretation Cytology Cytology Collection, Handling, Storage, and Transport Tips Collection Techniques FNB Needle and Syringe Selection Smear Techniques Evaluation Cytologic Criteria of Malignancy Figure 4.4: Cytologic Criteria of Malignancy Specific Tumor Cells Interpretation Fecal Cytology Vaginal Cytology Classifying Vaginal Cells Staging the Estrus Cycle Function Tests Hematology Complete Blood Count Hemacytometer Use Calculating a Differential Evaluation RBC Alterations and Morphology WBC Morphology WBC Alterations WBC Left Shift Platelet Morphology Platelet Alterations Coagulation Tests Coagulation Screening Coagulation Tests Blood Transfusions Crossmatching viii TABLE OF CONTENTS 75 76 83 Blood Typing Immunology and Serology Tests Microbiology Microbiology Collection, Handling, Storage, and Transport Tips Collection Techniques Specimen Storage Most Commonly Used Culture Media Culture Media Inoculation and Incubation Evaluation of Culture Growth Staining Solutions and Procedures Staining Problems Bacteria Identification Fungi Identification Parasitology Fecal Collection, Handling, Storage, and Transport Tips Endoparasite Examination Methods Fecal Flotation Solutions Blood Parasite Examination Methods Ectoparasite Examination Methods Figure 4.35: Relative Size of Parasite Eggs Endoparasites Ectoparasites Urinalysis Urine Collection, Handling, Storage, and Transport Tips Urine Examination/Urinalysis Gross Examination Preparation Chemistry Strip Examination Sediment Examination Reporting of Bacteria and Sperm Sediment Examination Urine Artifacts 83 84 84 85 85 86 88 88 88 88 89 90 91 92 93 94 95 96 97 97 98 98 104 105 108 108 108 108 112 113 114 115 115 115 115 116 119 119 Chapter 5: 120 120 122 122 123 124 125 126 127 127 130 130 133 134 134 134 137 138 139 139 139 145 147 147 147 148 149 149 150 151 151 155 Imaging 157 Radiology Radiographic Equipment Radiographic Exposure and Image Factors Radiographic Technique Chart Example 1: Veterinary X-Ray Technique Guide 159 160 161 161 162 Example 2: Veterinary X-Ray Technique Chart Evaluating Radiograph Technique Exposure Evaluation Density Evaluation Scale of Contrast Evaluation Radiographic Alterations Radiographic Artifacts Radiographic Positioning Directional Terms Positional Terms Soft Tissue Positioning Thorax Abdomen and Pharynx Head Positioning Skull Zygomatic Arch Tympanic Bullae Temporomandibular Joint Nasal Cavities and Sinuses Nasal Cavities and Sinuses (continued) Spine Positioning Cervical Thoracic–Lumbar Sacrum–Caudal Shoulder and Forelimb Positioning Scapula–Shoulder Humerus Elbow Radius/Ulna and Carpus Metacarpus/Phalanges Pelvis and Hindlimb Positioning Pelvis Femur, Stifles, and Tibia/Fibula Tarsus and Metatarsals Radiographic Contrast Studies Types of Contrast Media Fistula Contrast Studies Fistulography Abdominal Contrast Studies Peritoneography Gastrointestinal Tract Contrast Studies Esophagography and Gastrography Upper and Lower Gastrointestinal Study 163 164 164 164 164 166 167 167 168 168 169 169 169 170 170 171 172 172 173 173 174 174 175 175 176 176 176 177 178 178 179 179 180 181 181 182 183 183 183 183 184 184 185 Head Contrast Studies Dacryocystorhinography, Rhinography, and Sialography Spinal and Joint Contrast Studies Myelography and Epidurography Discography and Arthrography Urethra Contrast Studies Urethrography, Canine Urethrography, Feline Vaginal Contrast Studies Vaginography Urinary Tract Contrast Studies Cystography Cystography (continued) Additional Imaging Techniques Computer Tomography and Echocardiography Fluoroscopy Magnetic Resonance Imaging and Nuclear Medicine Ultrasonography Basic Scanning Technique Sites for Ultrasound Scanning 187 187 188 188 189 190 190 191 192 192 193 193 194 195 195 196 196 197 198 198 General Medicine 201 Cardiopulmonary Asthma and Brachycephalic Airway Syndrome Bronchitis and Cardiomyopathy, Hypertrophic Cardiomyopathy, Dilated Cardiomyopathy, Restrictive and Congenital Heart Disease Endocardiosis and Heartworm Disease Congestive Heart Failure Hypertension and Myocarditis Pneumonia and Pleural Effusion Rhinitis/Sinusitis and Tracheal Collapse Dermatology Acne Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis Food Hypersensitivity and Otitis Externa Pyoderma 204 204 205 208 Color Plate Chapter 6: TABLE OF CONTENTS 210 211 214 215 217 219 220 220 222 224 225 ix Endocrinology and Reproduction Abortion and Diabetes Insipidus Diabetes Mellitus Dystocia and Eclampsia Hyperadrenocorticism and Hyperparathyroidism Hyperthyroidism and Hypoadrenocorticism Hypoparathyroidism, Hypothyroidism, and Mastitis Pregnancy and Pyometra Gastroenterology Anal Sac Disease, Cholangitis, and Cholangiohepatitis Constipation and Megacolon Diarrhea Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus Hepatic Disease/Failure Hepatic Lipidosis and Inflammatory Bowel Disease Megaesophagus Pancreatitis and Peritonitis Protein-Losing Enteropathy and Vomiting Hematology Anemia and Disseminated Intravascular Coagulation Thrombocytopenia and von Willebrand’s Disease Infectious Diseases Brucellosis and Erhlichiosis Rocky Mountain Spotted Fever and Salmon Poisoning Tetanus and Toxoplasmosis Musculoskeletal Arthritis Cruciate Disease and Hip Dysplasia Osteochondrosis and Osteomyelitis Patellar Luxation and Panosteitis Neurology Encephalitis and Epilepsy Intervertebral Disc Disease and Meningitis Myasthenia Gravis and Myelopathy Vestibular Disease and Wobbler Syndrome Oncology Neoplasia Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor Various Neoplasias x TABLE OF CONTENTS 227 227 228 230 231 233 235 237 238 Ophthalmology Anterior Uveitis and Cataracts Conjunctivitis and Entropion Cilia Disorders and Glaucoma Keratitis and Keratoconjunctivitis Sicca Lens Luxation and Prolapsed Gland of the Third Eyelid Urology Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis Renal Failure Urinary Tract Obstruction and Urinary Tract Infection 238 240 241 243 245 246 248 249 251 253 253 254 256 256 258 259 261 261 263 264 266 267 267 269 271 272 273 273 275 277 Chapter 7: 284 284 285 287 288 290 292 292 294 296 Emergency Medicine 299 Emergency Medicine Emergency Supplies Telephone Assessment and Emergency Transportation Recommendations Inducing Vomiting At-Home Triage Primary Survey Hemostasis Cardiopulmonary Cerebrovascular Resuscitation (CPCR) Secondary Survey Shock Cardiovascular Emergencies Environmental Emergencies Gastrointestinal Emergencies Hematologic Emergencies Metabolic and Endocrine Emergencies Neonatal Emergencies Neonatal Resuscitation Post-Cesarean Neurologic Emergencies Ophthalmic Emergencies Renal and Urinary Emergencies Reproductive and Genital Emergencies Respiratory Emergencies Toxicologic Emergencies Toxins Trauma Emergencies 301 301 304 305 306 306 307 308 309 310 312 313 314 315 316 317 317 318 319 320 321 322 323 324 326 Section Four: Patient Care Skills 327 Chapter 8: Patient Care 329 Patient Monitoring Blood Pressure Blood Pressure Procedure Blood Pressure Results Central Venous Pressure Blood Gas Analysis Blood Gas Analysis Arterial Blood Gas Interpretation Acid-Base Disturbances Electrocardiogram ECG Procedure ECG Leads ECG Interpretation Figure 8.1 Normal Canine Electrocardiogram Heart Rate Calculation Common Rhythm Abnormalities Figure 8.2 Atrial Premature Contraction/Complex Figure 8.3 ST-Segment Elevation Figure 8.4 Ventricular Premature Contraction/ Complex ECG Problems and Artifacts Heat Administration Recumbent Patient Care Drug Administration Injections Intravenous Catheter Placement Peripheral and Jugular Arterial and Intraosseous Monitoring and Maintenance Chemotherapy Administration Toxicity Client Education: Monitoring Chemotherapy Response Insulin Therapy Client Education: Insulin Administration Client Education: Monitoring Insulin Response Client Education: Monitoring for Hypoglycemia Fluid Therapy Hydration Assessment 332 332 332 333 334 335 335 337 337 338 338 339 340 341 342 343 344 344 344 345 346 347 348 348 349 349 350 351 352 352 353 356 357 357 358 359 359 360 Chapter 9: Calculating Fluid Requirements Routes of Fluid Administration Commonly Used Fluids Fluid Additives Calculating Drip Rates Monitoring Fluid Therapy Blood Transfusions Blood Types Blood Collection Blood Products Blood Administration Blood Transfusion Reactions Oxygen Therapy Oxygen Administration Routes of Oxygen Administration Oxygen Hood and Nasal Catheter Transtracheal Catheter and Tracheostomy 361 362 363 365 365 366 367 368 369 371 373 374 375 375 376 376 377 Pain Management 379 Pain Management Pain Assessment Pain Scales Instructions for Using the CSU Acute Pain Scale Pain Levels Associated With Surgical Procedures, Injuries, and Illness Behaviors Suggesting Pain and Anxiety Nondrug Approach to Decrease Pain and Anxiety Pain Management Drugs Pain Management Techniques Constant Rate Infusions Setting Up a Morphine/Lidocaine/Ketamine Constant Rate Infusion 380 381 381 Chapter 10: Wound Care 382 383 384 386 386 392 392 393 395 Wound Treatment and Bandaging Wound Healing Process Classification of Wounds Factors Affecting the Healing Process Wound Care TABLE OF CONTENTS 396 396 397 398 399 xi Wound Cleaning Solutions Topical Wound Medications Wound Bandaging Bandage Care Bandaging Basic Bandage Robert Jones Bandage Chest/Abdominal Bandage Distal Limb Splint Casts Ehmer Sling 90–90 Flexion Velpeau Sling Hobbles Chapter 11: Parenteral Nutrition Nutritional Support Tips on Encouraging Oral Nutrition Enteral Nutrition Coax Feeding and Orogastric Tube Nasoesophageal/Nasogastric Tube Esophagostomy Tube Gastrotomy Tube Without Gastropexy Gastrotomy Tube With Gastropexy Jejunostomy Tube Enteral Nutrition Administration Parenteral Nutrition Parenteral Nutrition Parenteral Nutrition Administration Worksheet for Calculating Total Parenteral Nutrition (TPN) Worksheet for Calculating Peripheral or Partial Parenteral Nutrition (PPN) Chapter 12: Medical Procedures Gastrointestinal Procedures Stomach Tube and Gastric Lavage Gastrointestinal Tube Placement Verification Abdominocentesis and Diagnostic Peritoneal Lavage Enema, Warm Water xii TABLE OF CONTENTS 401 402 403 404 405 405 406 407 408 408 409 410 410 411 413 414 414 414 414 415 417 418 419 420 421 422 423 424 425 426 427 428 428 429 429 430 Ophthalmic Procedures Schirmer Tear Test, Fluorescein Sodium Stain, and Tonometry Respiratory Procedures Thoracocentesis and Thoracostomy Tube Placement Nebulization, Coupage, and Metered-Dose Inhalers Urogenital Procedures Urine Collection Urine Collection Devices Urinary Catheterization Urinary Catheter Maintenance 430 430 431 431 432 434 434 435 435 436 Section Five: Anesthesia and Anesthetic Procedures 437 Chapter 13: Anesthesia 439 Guidelines for Safe Anesthesia Preanesthetic Preanesthetic Evaluation Case-Based Anesthesia Preanesthetic Drugs Anesthesia Anesthetic Administration Anesthetic Machine Machine Setup Anesthetic Breathing Systems Anesthetic Administration General Anesthesia Induction Endotracheal Intubation Figure 13.1 Endotracheal Intubation Endotracheal Complications Perioperative Patient Care Intermittent Positive-Pressure Ventilation (IPPV) Anesthetic Monitoring Stages of Anesthesia Anesthesia Monitoring Postanesthesia Recovery Postanesthetic Monitoring Local and Regional Anesthesia Ventilation 441 442 442 444 451 451 451 451 451 452 453 453 454 455 456 456 456 458 458 458 460 466 466 467 470 474 General Information Administration Anesthetic Drugs Preanesthetic Drugs Anticholinergic Drugs Atropine and Glycopyrrolate Phenothiazines Acepromazine Maleate Benzodiazepines Diazepam and Midazolam α2-Agonists Xylazine and Medetomidine Opioids Butorphanol and Buprenorphine Fentanyl and Hydromorphone Morphine Sulfate and Oxymorphone HCl Injectable Induction Anesthetics Barbituates Thiobarbituates and Methylated Barbituates Cyclohexamines Ketamine and Tiletamine Propofol Propofol (continued) Etomidate Etomidate (continued) Inhalant Anesthetics Halothane and Isoflurane Sevoflurane Chapter 14: Dentistry Dentistry Anatomy Figure 14.1: Dentition: Canine and Feline Figure 14.2: Cross Section of a Triple-Rooted Tooth Figure 14.3: Skeletal Structure: Canine and Feline Figure 14.4: Cross Section of Facial Structures: Canine and Feline Dental Instruments and Equipment Hand-held Instruments Figure 14.5: Hand-held Non-mechanical Dental Instruments Instrument Maintenance 474 475 477 477 477 478 478 479 480 480 481 482 484 485 486 487 488 488 489 490 491 492 492 493 494 494 495 496 497 499 499 499 500 500 501 501 501 502 502 Sharpening Technique Mechanical Instruments Dental Prophylaxis Dental Cleaning Procedure Dental Charting Figure 14.6: Sample of Patient’s Dental Health Chart Common Dental Disorders Anatomical Disorders Pathologic Disorders Dental Radiology Equipment Technique Chart Radiographic Film Radiographic Techniques Radiographic Positioning Extractions General Extraction Procedures Local Dental Nerve Blocks Chapter 15: Surgery 503 503 504 504 506 509 510 510 511 512 512 512 513 513 514 517 517 518 521 Instrument Packs Preoperative Protocol Surgical Procedures Abdominal Surgery Abdominal Hernia, Anal Sacculectomy, and Colotomy Enterotomy, Gastric-Dilatation Volvulus, and Gastrotomy Intestinal Resection and Anastomosis and Hepatectomy Aural Surgery Aural Hematoma and Lateral Ear Canal Resection Integumentary Surgery Abscess and Laceration Mass Removal and Onychectomy Neurologic Surgery Disc Fenestration, Dorsal Laminectomy, and Hemilaminectomy Ophthalmic Surgery Cataracts, Ectropion, and Entropion Conjunctival Flap and Enucleation TABLE OF CONTENTS 523 524 525 525 526 528 529 530 530 531 532 533 534 535 536 537 538 xiii Glaucoma and Nictitating Membrane Flap Replacement Prolapse of the Gland of the Third Eyelid and Traumatic Proptosis Orthopedic Surgery Cranial Cruciate Ligament Repair, Femoral Head Ostectomy, and Fracture Repair Patellar Luxation, Total Hip Replacement, and Triple Pelvic Osteotomy Reproductive Tract Surgery Cesarean Section, Orchiectomy, and Ovariohysterectomy Postoperative Care of Neonates and Dam Thoracic Surgery Diaphragmatic Hernia, Laryngeal Paralysis, and Sternotomy Thoracotomy and Tracheal Collapse Urogenital Tract Surgery Cystotomy and Urethrostomy, Perineal Urethrostomy, Scrotal, and Urethrostomy, Prescrotal Suture Techniques Suture Patterns Knot Tying Postoperative Care Protocol Standard Postoperative Care Instructions Preventing Self-Trauma Alternative Surgical Options Endoscopy: Flexible Gastrointestinal and Rigid Laser Surgery Radiation Therapy: Teletherapy, Brachytherapy and Systemic Therapy Temperature Therapy: Hyperthermia and Cryosurgery 538 539 539 540 541 542 542 544 544 545 546 547 547 548 548 548 549 550 550 550 551 551 552 553 554 Section Six: Complementary and Alternative Veterinary Medicine and Pharmacology 555 Chapter 16: Complementary and Alternative Veterinary Medicine 557 Complementary and Alternative Veterinary Medicine (CAVM) Physical Therapy and Rehabilitation Traditional Chinese Medicine 558 558 562 xiv TABLE OF CONTENTS Ayurveda and Chiropractic Flower Essences and Homeopathy Laser Therapy Magnetic Field Therapy Western Herbal Medicine Chapter 17: Pharmacology Pharmacology Basic Calculations Drug Cross-Reference Antifungal Drugs Anti-infective Drugs Aminoglycosides, Cephalosporins, and Chloramphenicol Fluoroquinolones, Lincosamides, and Metronidazole Penicillin, Sulfonamides, and Tetracyclines Antiparasitic Drugs Antinematodals Antinematodals (continued) Anticestodals Ectoparasitics Ectoparasitics (continued) Cancer/Chemotherapy Drugs Alkylating Agents Anthracycline Antibiotics Antimetabolites Enzyme, Immunomodulating, Synthetic Hormone, and Vinca Alkaloid Cardiovascular Drugs Antianemics Antiarrhythmics Anticoagulants and Calcium Supplements Contractility Enhancers and Positive Inotropic Agents Diuretics Vasodilators Dermatologic Drugs Antiseborrheics Antipruritics/Antihistamines Gastrointestinal Drugs Antidiarrheals Antiemetics 563 564 565 565 566 567 570 570 571 574 575 575 576 577 578 578 579 579 580 580 581 581 582 583 584 585 585 586 587 588 589 590 591 591 591 592 592 593 Antiulcer Agents Emetics Enzyme, Laxatives, and Lubricants Protectants and Stool Softener Hepatic Drugs Supplements Metabolic Drugs Adrenal Cortex Pancreatic Pancreatic (continued) Parathyroid and Thyroid Musculoskeletal Drugs Anti-inflammatory Drugs Nonsteroidal Anti-inflammatory Drugs Nonsteroidal Anti-inflammatory Drugs (continued) Nonsteroidal Anti-inflammatory Drugs (continued) Protectant, Muscle Relaxer, and Supplement Neurologic Drugs Appetite Stimulator and Cholinergics Autonomic Nervous System: Adrenergic Agents: Alpha Stimulators Central Nervous System: Anticonvulsants Euthanasia Agents and Muscle Relaxers Analgesics Analgesic/Anticonvulsant, NMDA Antagonist, and Narcotic Agonist Analgesic: Opioids Analgesic: Opioids (continued) Behavioral: Antidepressants Ophthalmic Drugs Adrenergic Agonist, Carbonic Anhydrase Inhibitors, and Immunosuppressant Miotics, Mydriatics/Cycloplegics, Topical Anesthetics, and Stains 594 595 596 597 598 598 599 599 600 601 601 602 602 603 604 605 605 606 606 607 607 608 609 610 611 612 613 613 613 Otic Drugs Topical Anti-infectives Renal/Urinary Drugs Acidifers, Adrenergic Agent. and Alkalinizing Agent Alpha-Adrenergic Agent, Antibacterial/Acidifer, Anabolic Steroid, and Cholinergic Enzyme Inhibitor and Tricyclic Antidepressant Reproductive System Drugs Androgens, Estrogens, and Gonadotrpins Oxytocin, Progestins, and Prostaglandin Respiratory Drugs Antitussives Bronchodilators and Mucolytics Stimulants Toxicologic Drugs Chelating Drugs and Synthetic Alcohol Dehydrogenase Inhibitor Appendix 615 615 616 616 617 618 619 619 620 621 621 622 623 624 624 625 625 625 626 626 627 627 628 Metric Units Weights Liquid Measure Length Kilograms to Body Surface Area Temperature Conversion Disinfectants Glossary Abbreviations Bibliography Index 631 647 651 661 614 TABLE OF CONTENTS xv Figure List Chapter 1: Anatomy Figure 1.1 Overall Figure 1.2 Regional Lymph Nodes Figure 1.3 Musculature: Lateral View Figure 1.4 Skeletal: Lateral View Figure 1.5 Skeletal: Dorsal View Figure 1.6 Internal Organs: Left Lateral View Figure 1.7 Internal Organs: Right Lateral View Figure 1.8 Internal Organs: Ventral View Figure 1.9 Circulation: Dorsal View of Heart Figure 1.10 Circulation: Internal View of Heart Figure 1.11 Circulation: Heart Valves Figure 1.12 Circulatory: Lateral View Figure 1.13 Nervous System: Lateral View of Brain Figure 1.14 Nervous System: Lateral View Figure 1.15 Urogenital: Ventral View, Female Figure 1.16 Urogenital: Ventral View, Male Figure 1.17 Urogenital: Lateral View, Male Figure 1.18 Eye Figure 1.19 Ear 6 6 6 7 7 8 8 8 9 9 10 10 10 11 11 12 12 13 13 Chapter 3: Nutrition Table 3.2 Body Condition Score 61 Chapter 4: Laboratory Figure 4.4 Cytologic Criteria of Malignancy Figure 4.35 Relative Size of Parasite Eggs 93 139 Chapter 5: Imaging Table 5.4 Scale of Contrast Evaluation Table 5.7 Directional terms 165 168 Chapter 8: Patient Care Figure 8.1 Normal Canine Electrocardiogram Figure 8.2 Atrial Premature Contraction/Complex Figure 8.3 ST-Segment Elevation Figure 8.4 Ventricular Premature Contraction/Complex 341 344 344 344 Chapter 10: Wound Care Box 10.3 Basic Bandage Box 10.4 Robert Jones Bandage Box 10.5 Chest/Abdominal Bandage Box 10.6 Distal Limb Splint Box 10.7 Casts Box 10.8 Ehmer Sling Box 10.9 90–90 Flexion Box 10.10 Velpeau Sling Box 10.11 Hobbles 405 406 407 408 408 409 410 410 411 Chapter 13: Anesthesia Figure 13.1 Endotracheal Intubation 455 Chapter 14: Dentistry Figure 14.1 Dentition: Canine and Feline Figure 14.2 Cross Section of a Triple-Rooted Tooth Figure 14.3 Skeletal Structure: Canine and Feline Figure 14.4 Cross Section of Facial Structures: Canine and Feline Figure 14.5 Hand-held Nonmechanical Dental Instruments Figure 14.6 Sample of a Patient’s Dental Health Chart Table 14.10 Radiographic Positioning 499 500 500 501 502 509 514 Color Plate Anatomy Figure 1.6 Internal Organs: Left Lateral View Figure 1.7 Internal Organs: Right Lateral View Figure 1.8 Internal Organs: Ventral View Figure 1.9 Circulatory: Dorsal View of Heart Figure 1.10 Circulatory: Internal View of Heart Figure 1.12 Circulatory: Lateral View Figure 1.14 Nervous System: Lateral View Bone Marrow Figure 4.1 Canine Bone Marrow Figure 4.2 Canine Bone Marrow Figure 4.3 Maturation Stages of Megakaryocytes Tumor Cytology Figure 4.5 Histiocytoma CP-1 CP-1 CP-1 CP-1 CP-2 CP-2 CP-2 CP-3 CP-3 CP-3 CP-4 xvii Figure 4.6 Lymphoma Figure 4.7 Mast Cell Tumor Fecal Cytology Figure 4.8 Clostridium Figure 4.9 Giardia Figure 4.10 Campylobacter Figure 4.11 Spirochetes Figure 4.12 Yeast Hematology Figure 4.13 Canine Blood Smear Figure 4.14 Canine Distemper Figure 4.15 Feline Blood Smear Figure 4.16 Canine Blood Smear Figure 4.17 Feline Blood Smear Figure 4.18 Feline Blood Smear Figure 4.19 Canine Blood Smear Figure 4.20 Canine Blood Smear Figure 4.21 Babesia canis Figure 4.22 Cytauxoon felis Figure 4.23 Neutrophils Figure 4.24 Lymphocytes Figure 4.25 Monocytes Figure 4.26 Canine Blood Smear Figure 4.27 Eosinophils Figure 4.28 Basophils Figure 4.29 Canine Blood Smear Figure 4.30 Feline Blood Smear Figure 4.31 Canine Blood Smear Figure 4.32 Canine Blood Smear Figure 4.33 Blood Smear Ear Cytology Figure 4.34 Malessezia Endoparasites Figure 4.36 Ancylostoma caninum Figure 4.37 Ancylostoma tubaeforme Figure 4.38 Crytosporidium Figure 4.39 Didylidium caninum Figure 4.40 Dirofilaria immitis Figure 4.41 Echinococcus granulosus Figure 4.42 Giardia Figure 4.43 Isospora spp. Figure 4.44 Taenia spp. Figure 4.45 Toxocara canis xviii FIGURE LIST CP-4 CP-4 CP-4 CP-5 CP-5 CP-5 CP-5 CP-6 CP-6 CP-6 CP-6 CP-7 CP-7 CP-7 CP-7 CP-8 CP-8 CP-8 CP-8 CP-9 CP-9 CP-9 CP-9 CP-10 CP-10 CP-10 CP-10 CP-11 CP-11 CP-11 CP-11 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12 CP-12 Figure 4.46 Figure 4.47 Figure 4.48 Figure 4.49 Ectoparasites Figure 4.50 Figure 4.51 Figure 4.52 Figure 4.53 Figure 4.54 Figure 4.55 Figure 4.56 Figure 4.57 Figure 4.58 Urinalysis Figure 4.59 Figure 4.60 Figure 4.61 Figure 4.62 Figure 4.63 Figure 4.64 Figure 4.65 Figure 4.66 Figure 4.67 Figure 4.68 Figure 4.69 Figure 4.70 Figure 4.71 Figure 4.72 Figure 4.73 Figure 4.74 Figure 4.75 Figure 4.76 Figure 4.77 Figure 4.78 Figure 4.79 Figure 4.80 Figure 4.81 Figure 4.82 Figure 4.83 Figure 4.84 Figure 4.85 Figure 4.86 Toxocara cati Toxoplasma gondii Trichuris vulpis Uncinaria stenocephala CP-13 CP-13 CP-13 CP-13 Cheyletiella Ctenocephalides canis Demodex canis Dermacentor variabilis Linognathus setosus Otodectes cynotis Rhipicehpalus sanguineus Sarcoptes scabiei canis Trichodectes canis CP-13 CP-13 CP-13 CP-13 CP-14 CP-14 CP-14 CP-14 CP-15 Bacteria Bacteria Bacteria White Blood Cells White Blood Cells Epithelial Cells Epithelial Cast Fatty Cast Granular Cast Hyaline Cast Red Blood Cell Cast White Blood Cell Cast Waxy Cast Amorphous Phosphate Crystals Amorphous Urate Crystals Amorphous Biurate Crystals Bilirubin Crystals Calcium Carbonate Crystals Calcium Oxalate Dihydrate Crystals Cystine Crystals Leucine Crystals Sulfonamide Crystals Triple Phosphate Crystals Tyrosine Crystals Uric Acid Crystals Renal Epithelial Cells Squamous Epithelial Cells Transitional Epithelial Cells CP-15 CP-16 CP-16 CP-16 CP-16 CP-17 CP-17 CP-17 CP-17 CP-18 CP-18 CP-18 CP-19 CP-19 CP-19 CP-19 CP-20 CP-20 CP-20 CP-20 CP-20 CP-20 CP-21 CP-21 CP-21 CP-21 CP-21 CP-21 Figure Figure Figure Figure 4.87 4.88 4.89 4.90 Epithelial Cells and Lipid Droplets Capillaria plica Starch Granules Yeast CP-22 CP-22 CP-22 CP-22 Pain Scales Figure 9.1 CSU Canine Acute Pain Scale Figure 9.2 CSU Feline Acute Pain Scale CP-23 CP-24 FIGURE LIST xix Preface This second edition of Veterinary Technician’s Daily Reference Guide: Canine and Feline continues from the success of the first edition. As our profession continues to grow and demand more of veterinary technicians, this reference guide has done the same. With the obvious inclusion of updated medical information, this second edition contains an expansive amount of more in-depth skill descriptions allowing the technician to reach an even higher level of care. Its purpose is not to present ideas for the first time but rather to refresh or expand the veterinary technician’s current knowledge. This manual provides the link between the formal learning environment and the daily clinical setting. The goals are to increase confidence and technical skill and to allow veterinary technicians to provide clear client education. This book covers all areas of the veterinary technology profession pertinent to canines and felines, from the basics of physical examinations to advanced skills of chemotherapy administration. We are confident that the veterinary technician will find a daily need for this invaluable resource. In the end, it is our goal that this book will facilitate improved care for patients and the owners who rely on experienced veterinary technicians. SUMMARY OF KEY FEATURES Comprehensive Guide. This book was written as a quick reference guide. Its purpose is to assist an already trained and licensed veterinary technician throughout the work day—providing a refresher for a seldom-taken radio- graph, for example, or a pharmacology reminder to help answer a client’s question. The veterinary technology student will also find this book useful as a supplement to more in-depth textbooks as they finish training and join the workforce. Unique Chart and Table Format. The format of this book uses charts and tables for the efficient retrieval of pertinent information. As a result, very little prose text has been included. This unique format leads technicians straight to the answers they need to perform a task quickly. Extensive Art Program. The art program, which includes more than 200 illustrations and photographs, will provide visual assistance to the technician performing laboratory tests, dentistry, client education, and much more. The color insert makes the artwork very clear and easy to use. Expansive Indexing. A comprehensive table of contents and references at the beginning and throughout each chapter will ease the movement through this information-rich text. It is our expectation that this book will be of great assistance to the veterinary technician. Use of this book should result in enhanced performance of a veterinary technician’s duties and, therefore, improved care for patients. Candyce Jack, LVT Patricia Watson, LVT xxi Acknowledgments We would like to express our heartfelt thanks to all the people who gave support and guidance during the forming of this book. We also appreciate the professional courtesy extended by Phoenix Laboratory, DentaLabels, Wiley-Blackwell, American Society of Anesthesiologists, Dr. Peter Hellyer, Dr. Narda Robinson, Tara Raske, International Veterinary Association of Pain Management, Greg deBoer, Anne Rains, Dr. David Stansfield, Novartis, Dr. James H. Meinkoth, Oklahoma State University, Gary Averbeck, Dr. Robert K. Ridley, Kansas State University, and Dr. Jay R Georgi, Dr. Daniel Chan, and Mikki Cook, LVT, Hill’s Pet Nutrition, Animal Emergency and Trauma Center. Contributors Dina Andrews, DVM, PhD, Dip. ACVP Lisa Coyne, LVT Cindy Elston, DVM J. Michael Harter, DVM Joyce Knoll, VMD, PhD, Dip. ACVP Brita Kraabel, DVM Bob Kramer, DVM, Dip. ACVR Veronica Martin, LVT Linda Merrill, LVT, VTS (Small Animal Internal Medicine) Kathryn Michel, DVM, MS, Dip. ACVN Jeb Mortimer, DVM Richard Panzer, DVM, MS Patrick Richardson, DVM Nancy Shaffran, CVT, VTS (ECC) Stuart Spencer, DVM Cheryl Stockman, MT (ASCP) Laura Tautz-Hair, LVT, VTS (ECC) Sandy Willis, DVM, MVSc, Dip. ACVIM xxiii Veterinary Technician’s Daily Reference Guide: Canine and Feline Second Edition Section One Anatomy Chapter 1 1 Anatomy Anatomy 6 Figure 1.1. Overall 6 Figure 1.2. Regional Lymph Nodes 6 Musculature 6 Figure 1.3. Musculature: Lateral View 6 Skeletal 7 Figure 1.4. Skeletal: Lateral View 7 Figure 1.5. Skeletal: Dorsal View 7 Internal Organs 8 Figure 1.6. Internal Organs: Left Lateral View 8 Figure 1.7. Internal Organs: Right Lateral View 8 Figure 1.8. Internal Organs: Ventral View 8 Circulatory System 9 Figure 1.9. Circulatory: Dorsal View of Heart 9 Figure 1.10. Circulatory: Internal View of Heart 9 Figure 1.11. Circulatory: Heart Valves 10 Figure 1.12. Circulatory: Lateral View 10 Nervous System 10 Figure 1.13. Nervous System: Lateral View of Brain Figure 1.14. Nervous System: Lateral View 11 Urogenital 11 Figure 1.15. Urogenital: Ventral View, Female 11 Figure 1.16. Urogenital: Ventral View, Male 12 Figure 1.17. Urogenital: Lateral View, Male 12 Eye 13 Figure 1.18. Eye 13 Ear 13 Figure 1.19. Ear 13 10 5 1 ANATOMY For a veterinary technician to be able to accurately complete many of his or her daily tasks, a clear understanding of the anatomy of the canine and feline body is needed. The following diagrams show the basic layout of the body systems, highlighting the areas of interest that are most commonly accessed in daily medicine practices ranging from the correctly positioned radiograph to a single-stick venipuncture. Overall See Skill Box 2.6 Regional Lymph Node Examination, page 34. Figure 1.2 Regional lymph nodes. Musculature Sternocephalicus Cleidocervicalis External Trapezius abdominal Latissimus oblique dorsi Middle gluteal Superficial gluteal Biceps femoris Deltoids Cleidobrachialis Figure 1.1 Overall. Pectoralis major Triceps Sartorius Deep Gracilis pectoral Pectoralis minor Semitendinosus Figure 1.3 Musculature: lateral view. 6 SECTION ONE: ANATOMY Gastrocnemius Skeletal 1 See Skill Box 2.8 Orthopedic Examination, page 36. Orbit Zygomatic arch Zygomatic arch Atlas Axis Cervical Spinous Iliac Thoracic process Lumbar crest Ilium Ischial tuberosity Greater trochanter Maxilla Mandible Spine of scapula Scapula Wing of atlas Axis T1 Sacrum Ischium Costal arch Ribs Humerus Ulna Spine of scapula Scapula Xyphoid Patella Sternum Fibula Ulna Radius Carpus Metacarpus Femur Atlas Tibia Tarsus Metatarsus L1 Phalanges Figure 1.4 Skeletal: lateral view. Iliac crest Ilium Greater trochanter of femur Sacrum Ischial tuberosity Figure 1.5 Skeletal: dorsal view. CHAPTER 1 / ANATOMY 7 1 Internal Organs Esophagus See Skill Box 2.4 Abdominal Examination, page 33. See Color Plates 1.6–1.8. CP-1. Trachea Lung Heart Uterine horn Ovary Ureter Colon Right kidney Lungs Anus Diaphragm Liver Liver Gall bladder Common bile duct Liver Duodenum Pancreas Transverse colon Ascending colon Cecum Liver Heart Greater omentum (covering small intestines) Urinary bladder Figure 1.6 Internal organs: left lateral view. Rectum Esophagus Trachea Lungs Spleen Stomach Liver Thymus Ureter Small intestines Urinary bladder Figure 1.7 Internal organs: right lateral view. SECTION ONE: ANATOMY Spleen Jejunum Ileum Descending colon Mesentery Anal gland Left kidney Heart (cardiac notch) 8 Lesser omentum Stomach Greater omentum (cut) Colon Figure 1.8 Internal organs: ventral view. Circulatory System Left subclavian artery See Skill Box 2.2 Cardiac Examination, page 30. See Color Plates 1.9, 1.10, and 1.12. CP-1, 2. 1 Aorta Superior vena cava Left subclavian artery Superior vena cava Right auricle Right atrium Aortic arch Pulmonary arteries Left atrium Pulmonary veins Left auricle Right atrium Tricuspid valve Right ventricle Pulmonary veins Left ventricle Apex Inferior vena cava Coronary artery Right ventricle Apex Semilunar valves of aorta Left atrium Figure 1.9 Circulatory: dorsal view of heart. Bicuspid valve Left ventricle Chordae tendineae Ventral papillary muscle Figure 1.10 Circulatory: internal view of heart. CHAPTER 1 / ANATOMY 9 1 Figure 1.12 Circulatory: lateral view. Nervous System See Color Plate 1.14. CP-2. Epithalamus Corpus collosum Figure 1.11 Circulatory: heart valves. Cerebellum Olfactory bulb Optic chiasm Spinal cord Thalamus Medulla oblongata Hypothalamus Pituitary Figure 1.13 Nervous system: lateral view of brain. 10 Urogenital Vagosympathetic trunk Brachial plexus Lumbo-sacral plexus 1 See Skill Box 2.4 Abdominal Examination, page 33. See Skill Box 12.10 Urinary Catheterization, page 435. Vagus Sciatic Diaphragm Femoral Radial Esophagus Adrenal gland Tibial Median Kidney Ulnar Uterine tube Figure 1.14 Nervous system: lateral view. Ovarian ligament Ovary Colon Ureter Round ligament Broad ligament Uterus: Horn Body Urinary bladder Urethra Rectum Vagina Anal gland Figure 1.15 Urogenital: ventral view, female. CHAPTER 1 / ANATOMY 11 Kidneys 1 Colon Diaphragm Esophagus Prostate gland Adrenal gland Kidney Urethra Ureter Urinary bladder Spermatic cord Prepuce Ureter Colon Ductus deferens Epididymis Urinary bladder Testis Prostate gland Spermatic cord Urethra Rectum Bulbourethral gland Ductus deferens Penis Prepuce Glans penis Epididymis Anal gland Testis Figure 1.16 Urogenital: ventral view, male. 12 SECTION ONE: ANATOMY Os penis Glans penis Figure 1.17 Urogenital: lateral view, male. Eye Ear Bulbar conjunctiva Sclera 1 See Skill Box 2.5 Otoscopic Examination, page 33. See Skill Box 2.13 Ear Cleaning and Flushing, page 55. Posterior chamber Choroid Retina Pinna Iris Cornea Vitreous humor Lens Optic disc Anterior chamber Third eyelid Suspensory ligament Optic nerve Palpebral conjunctiva Vertical auditory canal Figure 1.18 Eye. Semicircular canals Vestibule Cochlea Oval window Horizontal auditory canal Auditory nerve Round window Tympanic membrane Middle ear cavity Eustachian tube (auditory) Figure 1.19 Ear. CHAPTER 1 / ANATOMY 13 Section Two Preventative Care Chapter 2: Preventative Care and Vaccinations Chapter 3: Nutrition 57 17 Chapter 2 2 Preventative Care and Vaccinations Physical Examinations 18 Preliminary Examination 19 Physical Examination 20 Pediatric Physical Examination 23 Normal Parturition 26 Care and Feeding of Orphaned Puppies and Kittens 27 Geriatric Physical Examination 28 Cardiac Examination 30 Pulmonary Examination 32 Abdominal Examination 33 Otoscopic Examination 33 Regional Lymph Node Examination 34 Neurologic Examination 34 Orthopedic Examination 36 Vaccinations 37 Guidelines to Follow When Vaccinating an Animal 37 Canine Transmissible Diseases 38 Coronavirus, Distemper 38 Hepatitis, Infectious Tracheobronchitis 39 Leptospirosis, Lyme Disease 41 Parvovirus, Rabies 42 Canine Vaccination Protocol 44 Feline Transmissible Diseases 44 Feline Calicivirus 44 Feline Infectious Peritonitis 46 Feline Panleukopenia Virus, Feline Immunodeficiency Virus 47 Feline Leukemia Virus, Feline Rhinotracheitis Virus 49 Feline Vaccination Protocol 51 Animal Care 51 Client Education: Home Dental Care 52 Grooming 53 Bathing 53 Nail Trimming 54 Anal Sac Expression 54 Ear Cleaning and Flushing 55 17 Key Words and Phrasesa Alopecia Amyloid Axillary Canarypox vector Core Cryptorchidism Desquamative Diathesis ELISA Encephalopathy Epistaxis Fistula Fontanelle Granulomatous Halitosis Hemoagglutination Hyaluronic acid Hyperpathia Intussusception Lymphadenopathy 2 a Lyophilized Melena Noncore Nystagmus Panniculus Papilloma PCR Petechia Prodromal Proprioception Proteoglycan Rales Rhonchi Stenosis Strabismus T-lymphocytes Tortuous, redundant aorta Vascularity Western blot Whelping Abbreviations Additional Resources, page APTT, activated thromboplastin time BCS, body condition score BUN, blood urea nitrogen CBC, complete blood count CNS, central nervous system CPV, canine parvovirus CSF, cerebrospinal fluid DIC, disseminated intravascular coagulation ELISA, enzyme-linked immunosorbent assay F, Fahrenheit FCV, feline calicivirus FECV, feline enteric coronavirus FeLV, feline leukemia FHV-1, feline viral rhinotracheitis FIP, feline infectious peritonitis FIV, feline immunodeficiency virus FPV, feline panleukopenia GIT, gastrointestinal tract IFA, immunofluorescent assay IgG, immunoglobulin gamma G IgM, immunoglobulin gamma M IN, intranasal O2, oxygen OVH, ovariohysterectomy PCR, polymerase chain reaction PT, prothrombin time RBC, red blood cell RV, rabies vaccine SQ, subcutaneously v, variable Abdominocentesis, 429 Anesthesia, 439 Blood transfusions, 367 CBC, 105 Cesarean section, 542 Chemistry panel, 74 Coagulation tests, 115 Coupage, 432 Dentistry, 497 Ear cytology, 88 Figure: Ear, 13 Figure: Heart, 9 Figure: Internal organs, 8 Figure: Heart valves, 10 Figure: Lymph nodes, 6 Fluid therapy, 359 General medicine, 201 Heat administration, 346 Injections, 348 Laboratory, 71 Microbiology, 122 Nebulization, 432 Nutritional support, 414 Oxygen therapy, 375 Pharmacology, 567 Physical examination, 18 Physical therapy, 558 Radiology, 159 Surgery, 521 Thoracocentesis, 431 Urinalysis, 147 Key words and terms are defined in the glossary on page 631. PHYSICAL EXAMINATIONS A well-done physical examination gives the clinician invaluable information in the assessment of an animal’s health. Technicians can assist the veterinarian by understanding the pertinence of each part of the examination and by 18 SECTION TWO: PREVENTATIVE CARE being able to conduct an examination in an orderly, precise, and timely fashion. Physical examinations are conducted prior to immunizing, before an anesthetic procedure, and in conjunction with any visit to the veterinarian for a specific problem. The following charts will cover methods and specific areas of the physical examination in both pediatric and adult patients. Vital Signs History Table 2.1 / Preliminary Examination Definition/Normal/Abnormal Equipment and Technique Chief Complaint • The current issue for which the owner is bringing the animal to the clinic • Current history • Current appetite, water intake, urination and defecation behavior, recent temperament, and current medications are noted. Recent activities to which the animal may have been exposed or changes in the home environment are also noted. Past History • Previous medical conditions that may exacerbate the current complaint • Past history • Immunization dates as well as current medical therapies are noted. Signalment • Age, breed, sex, and reproductive status • N/A General Appearance • The patient’s overall health • Visual evaluation of the condition of animal’s coat, skin, and temperament Heart Rate • Cardiac function Normal • Canine: 70–180 beats/min • Feline: 110–220 beats/min Abnormal • Canine: <70 and >160 beats/min • Feline: <100 and >200 beats/min • Direct palpation of chest wall or pulse • Auscultation of the thoracic cavity • See Skill Box 2.2, Cardiac Examination, page 30. • Electrocardiograph • See Chapter 8, Patient Care, page 338. • Doppler pulse monitor Respiration • Reflects proper oxygenation of the body’s tissues • Ability to eliminate carbon dioxide from the blood Normal • Canine: 10–30 breaths/min • Feline: 25–40 breaths/min Abnormal • <8 breaths/min • Auscultation of the thoracic cavity • See Skill Box 2.3, Pulmonary Examination, page 32. • Pulse oximetry • Calculates the O2 saturation of hemoglobin in circulating RBCs • The probe is placed on an easily accessed capillary bed (e.g., tongue, lip fold, nasal septum, pinna, prepuce, vulva, skinfolds, or toe web) • Normal: 99–100% • Abnormal: <97%, 90% is hypoxemia and must be corrected Pulses • Cardiac function Normal • Match rate and rhythm of heart rate Abnormal • Weak, bounding, thready, irregular, deficits • Direct palpation • Direct digital pressure over the left and right femoral artery • Evaluate pulse quality, strength, rate and symmetry. Mucous Membranes • Blood loss, anemia, and poor perfusion Normal • Pink Abnormal • Pale: blood loss, anemia or poor perfusion • Cyanotic: shortage of oxygen • Visual observation • Observed at the gingival, tongue, buccal mucous membranes, conjunctiva of the lower eyelid, mucous membrane lining the prepuce or vulva Capillary Refill Time • Reflects the perfusion of tissues with blood Normal • 1–2 seconds Abnormal • >2 seconds • Direct palpation • Direct digital pressure is applied to the mucous membranes until blanched and then timed for blood (pink color) to return. Temperature • Circulation Normal • 100.5–102.5° F Abnormal • <100° and >103° F • Direct palpation of paws and ears • Rectal thermometer • Temperature probe (e.g., rectal or esophageal) Weight Normal/Abnormal • See Table 3.2, Body Condition Scoring System, page 61. • Recorded in kilograms and pounds • Note BCS and dietary history CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 2 19 Table 2.2 / Physical Examination Area Head and Neck 2 20 Specific Region Examination Findings History Head (general) • Symmetry, alopecia, tumors or swellings, rashes, head tilt, and uniformed muscle mass on skull • Head tilt or shaking? • Seizures? Eyes (lids, eyeball, conjunctiva, sclera, pupil, cornea, lens) • Visual examination • Ophthalmic examination • Normal: bright, clear, uniform, responsive • Cysts, conformity, lash growth, third eyelid position and size, symmetry, ocular discharge, nystagmus, positioning within orbit: protruding vs. sunken, color, vascularity, uniformity of pupils, scars, ulcerations, pigmentation, and opacities • Pain? • Blinking, squinting, rubbing or pawing? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral) • Blindness? Muzzle • Visual examination • Symmet, inflammation, swelling, abscessed teeth and pain on opening mouth • Rubbing or pawing? Nares • Visual examination • Symmetry, movement on inspiration (should move laterally) and discharge • Sneezing or heavy breathing? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral) Oral Cavity (lips, mucous membranes, teeth, hard and soft palate, tongue, pharynx, tonsils) • Visual examination • Normal: symmetrical, pink, slightly moist • Halitosis, inflammation, tumors or papillomas, anatomic defects, excessive salivation, crusting, pigment changes, color and capillary refill time, tacky, periodontal status, ulcerations, and foreign bodies • See Chapter 14, Dentistry, page 497. • Excessive salivation or dripping water after drinking? • Inappetence or difficulty eating? • Changes? (e.g., gingival pigmentation, bark, meow) Ears • Visual examination • Otoscopic examination • Normal: clear and dry • Debris, exudate, odor, inflammation, response to sound, and sensitivity to canal massage or palpation • See Skill Box 2.5 Otoscopic Examination, page 33. • Shaking head or scratching ears? • Discharge? (e.g., quantity, consistency, color, uni- or bilateral) • Hearing loss? Lymph Nodes (submandibular) • Palpation • Normal: firm, oval, and freely movable • Symmetry and size • See Skill Box 2.6 Regional Lymph Node Examination, page 34. • Increase in size? Salivary Glands (mandibular, parotid) • Palpation • Normal: irregular, bumpy texture • Symmetry and size (do not confuse with submandibular nodes) Neck (throat, trachea, larynx, thyroid, thoracic inlet) • Palpation • Auscultation • Coughing or sounds during examination, deviation or displacement, tumors, swelling, stridor, or jugular pulse waves SECTION TWO: PREVENTATIVE CARE • Gagging, retching, difficulty swallowing? • If a cough is noticed, does the cough occur throughout the day? • Travel or exposure to other dogs? Table 2.2 / Physical Examination (Continued) Thoracic Cavity Trunk and Limbs Area Specific Region Examination Findings History Trunk (general) • Visual examination • Palpation • Normal: visible sheen and coat completeness • Body form and weight, symmetry, tumors, alopecia, inflammation, ectoparasites or their residues, crusts, scales, pustules, and hydration status • Changes? (e.g., pigmentation, odor, hair loss, texture) • Allergen exposure? (e.g., type of bedding, feathers, carpets, indoor plants, tobacco smoke) • Pruritus? (e.g., behavior, frequency) • Scratching, biting, licking? • Did pruritus precede or coincide with lesions? • Bathing or grooming habits? • Changes in diet? Lymph Nodes (prescapular, axillary, inguinal, popliteal) • Palpation • Normal: firm, oval, and freely movable (axillary or disc shaped) • Size and consistency • See Skill Box 2.6 Regional Lymph Node Examination, page 34. • Increase in size? • Limping and/or favoring limb(s)? Limbs (muscle, bone, joints, paws) • Visual examination • Palpation • Symmetry, inflammation, tenderness, tumors, range of motion, gait, atrophy, flexion and extension, interdigital, nails/nail bed, and knuckling • Licking paws? Lungs • Auscultation • Percussion • Rate, depth, and pattern of breathing (rales or rhonchi) and lung sounds (absence of lung sounds may indicate pleural effusion, and dull sound may indicate fluid filled or solid lungs) • See Skill Box 2.3 Pulmonary Examination, page 32. • Fainting? • If cough is present, does it change throughout the day or worsen with exertion? • Recent travel? Heart • Auscultation • Dysrhythmias, murmurs, verify femoral and metatarsal pulses coincide with the heart rate (e.g., no pulse deficits) • See Skill Box 2.2 Cardiac Examination, page 30. • Fainting, collapsing, or exercise intolerance? • Panting? • Coughing? (e.g., description, frequency) CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 21 2 Table 2.2 / Physical Examination (Continued) Area Perineal Abdomen 2 22 Specific Region Examination Findings History Kidneys • Palpation • Normal: oval shaped with indented side, firm, and smooth • Size, shape, contours of surface, symmetry (between left and right kidneys) and pain • Excessive water consumption or urinating? Liver • Palpation, lateral recumbency • Normal: edges are smooth and well defined • Asymmetric or irregular surface? • Extension beyond costal arch may indicate hepatomegaly Urinary Bladder • Palpation • Normal: palpable when urine filled, thin wall with flexibility • Size, tone and turgidity • Urination (e.g., frequency, quantity, behavior, odor) • Foul odor, color change, or blood? • Straining? • Inappropriate urination? Small Intestines • Palpation • Normal: not palpable or mildly gas filled • Tumors, foreign bodies, and pain, thickened/firmness on palpation • Vomiting, diarrhea, or constipation? (e.g., description, quantity, frequency, behavior) • Time since last bowel movement? Mammary Glands • Visual examination • Palpation • Normal: fleshy, semifirm, or fatty character • Estrus/diestrus: firmer and enlarged • Tumors, cysts, inflammation, temperature, discharge (suppurative), pain, and firmness • If intact female, when last whelping occurred? • When was OVH performed? General • Visual examination • Tumors, fistulas, exudate and hernias • Reproductive status? Vulva • Visual examination • Normal: lochia • Size, inflammation, and discharge from or between perivulvar folds • Last heat cycle, mating, or whelping? • Discharge (e.g., quantity, consistency, color, odor) Penis • Visual examination • Palpation • Normal: preputial discharge • Tumors, inflammation, and discharge • Normal urination? • Blood or urine color change? • Discharge (e.g., quantity, consistency, color, odor) Scrotum • Visual examination • Palpation • Descended testicles, swelling, and symmetry • Pain when sitting? SECTION TWO: PREVENTATIVE CARE Table 2.3 / Pediatric Physical Examination This chart is designed to show the specific areas to note on puppies and kittens. A full examination should be conducted following Table 3.3, General Physical Examination. Age Puppy Normal Temperament • Visual examination Birth–6 weeks • First 2–3 weeks should consist of eating and sleeping. • Nursing should be vigorous and active with a good “suckle reflex.” • Active playtime with mother and littermates from 3 weeks on Body Weight Birth–4 weeks • • • • • 5 weeks–6 months • Gain 1–2 g/day/lb of adult body weight • Obtained 50% of adult weight • Gain 10–15 g/day on average Reached adult weight • Small breed: 8–12 months • Medium breed: 12– 18 months • Large–giant breed: 18–24 months • By maturity, most canines will ↑ birth weight 40–50× • 10 months Coat/Skin • Visual examination • Flea comb Birth–6 months • Shiny and complete hair coat • State of hydration • Completeness of hair cover, condition of foot pads, wounds, bacterial infections, external parasites, or dermatophytosis Temperature • Rectal thermometer Birth–1 week • 96–98° F • Cannot regulate own body temperature for first 3 weeks (puppy) or 1 week (kitten) • Neonates should never be left unattended or warmed on electric heating pads, because their neuromuscular reflexes are not present until 7 days of age. • Hyper- or hypothermia • Burns 2–4 weeks • 99–100.5° F General Appearance Specific Region/Examination Method Toy: 100–400 g Medium: 200–300 g Large: 400–500 g Giant: >700 g Birth weight should double in days 10–12 Kitten Normal • 100 g • Birth weight should double in 14 days. Evaluation • Constant crying, extreme inactivity, and/or failure to gain weight can be signs of inadequate milk consumption. • Separation from mother and littermates before 6 weeks of age can lead to numerous behavioral problems later in life. • Failure to gain weight is often the first sign of illness. • Body weight should be checked initially, 12 hours after birth, and daily for 2 weeks; then checked weekly. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 23 2 Table 2.3 / Pediatric Physical Examination (Continued) Head 2 24 Specific Region/Examination Method Age Puppy Normal Eyes • Visual examination • Penlight • Ophthalmic examination Birth–6 months • Eyes open around 5–14 days • Iris is blue gray. • Changes to adult color at approximately 4–6 weeks of age • Adult vision at 5–10 weeks of age • Pupillary light responses may not be evident until 21 days of age. • Strabismus or deviation of eyes at 3–5 months of age • Discharge, squinting or holding eye(s) closed, rubbing or pawing at eye(s) Ears • Visual examination • Otoscopic examination Birth–6 months • Complete hearing at 4–6 weeks of age • External ear canals open at 6–14 days and are completely open by 17 days. • Canals may be full of desquamative cells and some oil droplets. • Size and position • Exudate and odor for possible bacterial or yeast infection or mites Mouth • Penlight • Tongue depressor or cotton swab Birth–3 months • Sucking reflex is present at birth and disappears at 3 weeks of age. Deciduous tooth eruption • Incisors: 2–4 weeks • Canines: 3–5 weeks • Premolars: 4–12 weeks • Hairlip, cleft palate, sucking reflex, occlusion or malfunction of jaw bones (malocclusion) 4–6 months Permanent tooth eruption • Incisors: 3–5 months • Canines: 4–7 months • Premolars: 4–6 months • Molars: 4–5 months • Occlusion or malfunction of jaw bones (malocclusion) Nose • Visual examination Birth–6 months • Normal adult appearance • Obstruction, stenosis, discharge, or abnormal shape, swelling Skull • Visual examination Birth–4 weeks • Normal adult appearance • Open fontanelle (soft spot on the forehead) SECTION TWO: PREVENTATIVE CARE Kitten Normal Evaluation Table 2.3 / Pediatric Physical Examination (Continued) Age Puppy Normal General Appearance • Visual examination Birth–6 months • Symmetrical chest wall • Wounds and rib fractures • Congenital sternal or spinal abnormalities Limbs Perineum Genitals Kitten Normal Evaluation Heart • Visual examination • Stethoscope with 2 cm bell and 3 cm diaphragm Birth–4 weeks • Heart rate: 220 beats/min • Heart rhythm is a regular sinus rhythm • Heart rate and pattern • Murmurs (should be noted and veterinarian consulted, as some can be normal/physiologic) 5 weeks–6 months • Heart rate: 70–180 beats/min • Heart rate: 110–200 beats/min Lungs Birth–4 weeks • Respiratory rate: 15–35 breaths/min • Respiratory rate: 25– 35 breaths/min 5 weeks–6 months • Respiratory rate:10–30 breaths/min • Respiratory rate: 25– 40 breaths/min General Appearance • Visual examination Birth–4 weeks • Umbilical cord falls off in 2–3 days. • Umbilical hernia, inflammation, or infection/ulceration Internal Organs • Palpation Birth–4 weeks • Kidneys are palpable in kittens and some puppies. • Normal spleen will sometimes be palpable in an older puppy if foreleg is extended, allowing organs to fall caudally; spleen only palpable if enlarged in kittens. • Liver margins should not extend past the ribs. • Stomach will feel like a large fluid-filled sac if full. • Intestines are soft and freely movable without pain and may be fluid or gas filled. Thickened/ ”ropy” feel may indicate endoparasitism. • Urinary bladder should have resistance to urine outflow. • Enlarged or abnormally small organs, pain on palpation, masses • Intussusception—a sausage-like mass and very painful Forelimbs/Hindlimbs • Visual examination • Palpation Birth–6 months • Normal adult appearance (breed-influenced) • Wounds, bruises, or swelling • Deformities or ↑ or ↓ range of motion in joints Genitalia • Visual • Palpation Birth–6 months • Normal adult appearance • Descended testicles by 4–6 weeks of age (diagnose cryptorchid after 16 weeks) • Cryptorchidism, vaginitis, congenital abnormalities Anus • Visual • Palpation Birth–6 months • Normal adult appearance • Rectal prolapse, inflammation, or irritation • Defecation/urination on their own usually occurs at 2–3 weeks. 2 Abdomen Thorax Specific Region/Examination Method • Breathing rate and pattern • Asymmetrical or absent lung sounds CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 25 Table 2.4 / Normal Parturition 2 In late term pregnancy (58–63 days), the bitch or queen should be observed for signs of labor. These may include a rectal temperature drop to <100° F, vulvar discharge, and leaking milk. Once labor starts, the female should be left alone but observed occasionally progression and/or signs of complications. Stage Time Observations Complications I Prelabor • 6–12 hours, up to 24 • Restless, nesting behavior, getting up and down, nervous, panting, vomiting • Nesting behavior (e.g., arranging bedding, chewing up paper) • Black, green, or red vaginal discharge II Active Labor, Whelping III Expulsion of Placenta • 3–6 hours, up to 24 • Contractions lying on side or standing in a urination stance • Placenta at the vulva, a neonate should be seen within 15 minutes • Mother will chew the placenta to free the neonate, sever the umbilical cord, and lick the neonate for stimulation. • Placenta should be seen within 5–15 minutes. • The next neonate should follow in 1–2 hours. • 30–60 minutes of strong contractions with no neonate produced • >2 hours between pups (>1 hour between kittens) is an emergency • Mother may not release the neonate and sever the umbilical cord. • Eating multiple placentas may lead to indigestion and diarrhea. • Queen: if stressed may stop and restart labor the next day Postpartum • 1–2 months • Bitch: 8–10 weeks of bloody discharge • Queen: 3 weeks of black or red discharge • Mastitis (e.g., fever, lethargy, swollen glands), metritis (e.g., foul smelling discharge), retained placenta (e.g., green discharge) • Eclampsia (e.g., tremors, excitation) 26 • 20–60 minutes per neonate SECTION TWO: PREVENTATIVE CARE Skill Box 2.1 / Care and Feeding of Orphaned Puppies and Kittens Housing • Use a box with tall sides to avoid escape, such as a cardboard pet carrier. • Line the bottom of the box with towels and place a diaper or pee pad on top for easy cleaning. • The box will need to be cleaned frequently to keep the neonates clean and dry. Temperature • Neonates are unable to maintain their own body heat; they rely on the ambient temperature and littermates. • The environment should be draft free with a ambient temperature gradient measured by a thermometer. • Electric heating pads and heat lamps should not be used due to the risk of overheating and burns. • The ambient temperature should be 85–90° F for the first week, 80° F for weeks 2–4, and 70° F for week 5. • Warm the formula to a comfortable temperature, place the neonate in a comfortable dorsal position, and hold the bottle up in a position to closely mimic that of the mother. Ensure that the nipple does not contain air and the bottle is tipped up to avoid air ingestion. Neonates have a vigorous suckling response and can overfeed if not monitored. Milk bubbling out of the neonate’s nose may indicate overzealous feeding or a hole in the nipple that is too large. A satisfied neonate is quiet with a slightly enlarged abdomen. Following each feeding, burping may be necessary to expel excess air ingested. • A nipple bottle is most commonly used, but a feeding tube can be ideal in skilled hands for weak or premature neonates See Skill Box 11.3 Nasoesophageal/Nasogastric Tube, page 415. • With all methods of feeding, care should be taken to avoid aspiration pneumonia, a complication seen with forced nursing, squeezing the bottle, improper feeding tube use, and volume overload. Health • Hydration should be monitored in the neonate by mucus membranes, eyes, urine specific gravity, and urine color. Diet • A neonate should gain 10% of its birth weight daily. • Commercial replacement diets (e.g., Esbilac, KMR) are the best choice for diet replacement. • Crying for >15 minutes is a sign of distress (e.g., hunger, cold, neglected, pain). • When commercial diets are not available, the following recipe can be used in the interim. Urination and Defecation • 1/2 cup whole milk, 1/2 cup water, 1 tsp. salad oil, 1 drop multivitamins, 2 egg yolks, 2 Tums (antacid) crushed • For the first 3 weeks, the neonate must be stimulated to urinate and defecate after each feeding. • Blend all ingredients in a blender, keep refrigerated, and use within 48 hours. • With the neonate held securely in 1 hand (possibly with a towel) over a sink, gently massaging the lower abdomen in a circular motion. The genitals may also be rubbed with a warm, moist cotton ball. • The above diet provides 1.2 kcal/mL, which is the same as commercial diets. • Neonates are fed 22–26 kcal/100 g body weight for the first 12 weeks of life. The diet should be gradually increased over 2–3 days to the recommended daily amount to avoid overfeeding and diarrhea. • The genitals should be cleaned and dried to avoid skin irritation. • Urine and feces should be seen at almost every feeding and in the box. • Feces should be soft, but not green or yellow watery. Overfeeding is the most common cause of diarrhea; further dilute the formula by 1/3 for 2 days. Feeding • The neonate will cry when hungry, but feeding should initially be expected every 2–3 hours. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 27 2 Table 2.5 / Geriatric Physical Examination This chart is designed to show the specific areas to note on geriatric animals. A full examination should be conducted, following Skill Box 2.2, General Physical Examination. However, geriatric animals go through additional changes as a result of the natural aging process and a physical is recommended every 6 months. Many of these changes cannot be visualized on a physical examination, but they may be inferred through the general examination and from discussion with the owner. These symptoms may contribute to or initiate more serious medical conditions, thereby making their determination valuable to the clinician. General Appearance Specific Region Head 2 28 Effects Associated With Skin • ↓ Elastin and collagen • ↓ Blood flow to skin • Thinning of skin and coat • Ineffective barrier to pathogens • May require more maintenance by owner Toenails • ↑ Length because of ↓ activity • More fragile, crumble when trimmed • Difficulty walking • Wounds in foot pads Musculature • ↓ Strength • ↓ Tone • Muscle atrophy and coordination Eyes • • • • • Atrophy of the iris and ciliary muscles • Nuclear sclerosis Ears • Hearing loss • Loss of cochlear hair cells Nose • ↓ Sense of smell • ↓ Function of olfactory nerve endings, which can affect their eating habits Neck • Thyroid nodules • Hyperthyroidism (feline), tumor SECTION TWO: PREVENTATIVE CARE Vision loss ↓ Pupillary light response Change in lens opacity Optic lens hardening Associated With Brain • Amyloid deposition • Memory loss • Personality changes • Cognitive dysfunction disorder • ↓ Glucose tolerance • Cognitive dysfunction disorder Lungs • • • • • • Rarely a cause of concern unless patient needs to undergo an anesthetic procedure Heart • ↑ Sternal contact • Tortuous, redundant aorta (feline) • Radiographic changes Kidney • • • • • Liver • ↓ Protein synthesis • ↓ Metabolic function • Liver disease Limbs Specific Region Joints/Cartilage • ↓ Production of chondroitin sulfate, keratin sulfate, and hyaluronic acid • ↓ Proteoglycan content • Degenerative joint disease Urethral Sphincter • ↓ Tone • Primary urethral sphincter incontinence Immune System • ↓ Function • Chronic disease • ↑ Susceptibility to infections Blood • ↓ Ability to respond to RBC demand • Hypertension • Anemia • Renal or endocrine disease Internal Organs Effects Genitals Table 2.5 / Geriatric Physical Examination (Continued) Loss of lung elasticity ↓ Tidal volume ↓ Expiratory reserve Diminished cough reflex ↑ Density on lung radiographs ↓ ↓ ↓ ↓ ↑ Size Glomerular filtration rate Renal blood flow Ability to handle potassium Mineralization of renal pelvis 2 • Rarely a cause of concern • Kidney disease • PU/PD • No concern known CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 29 Skill Box 2.2 / Cardiac Examination 2 Cardiac Examination Technique Perform auscultation in a quiet room with a calm patient. Place the patient in a standing or sitting position. Avoid listening to recumbent animals, as the change in heart position and configuration leads to errors. The flat diaphragm is used to detect high-frequency sounds (e.g., normal heart and breath sounds, most murmurs), while the bell is used to detect lower-frequency sounds (e.g., 3rd and 4th heart sounds, diastolic murmurs). The entire heart is examined, paying particular attention to the cardiac valves. Begin by placing the diaphragm gently but firmly at the left apex, where the first heart sound is best heard and also the location of the mitral valve. From here, inch the stethoscope to the left base of the heart, which is approximately 2 rib spaces cranial and slightly dorsal. Note the second heart sound and possible aortic and pulmonic stenosis murmurs. Next, palpate the right apex of the heart and move the stethoscope to this region. This is the tricuspid region and possible location of tricuspid regurgitation. Then move to the right base of the heart and observe for subaortic stenosis. Once an abnormality is noted, the surrounding region should be evaluated to find the point of loudest sound. In this process, the entire heart region should be evaluated and a complete examination given. Rate • Canine: 70–180 beats/min • Feline: 110–220 beats/min Heart Sounds Heart Valves Normal Normal • First heart sound (S1) • Location: left apex of the heart • Sound: low-frequency sound longer than S2 • Pulmonic • Location: left 2nd–4th intercostal space above the sternal border • Second heart sound (S2) • Location: base of the heart • Sound: high-frequency sound shorter than S1 • Third heart sound (S3) • Location: apex • Sound: low-intensity sound shortly after S2 • Fourth heart sound (S4) • Location: apex • Sound: low-intensity sound slightly before S1 30 SECTION TWO: PREVENTATIVE CARE • Aortic • Location: left 3rd–5th intercostal space at mid-thorax • Mitral • Location: left 4th–6th intercostal space just above the sternal border, the apex of the heart • Tricuspid • Location: right 6th–7th intercostal space at mid-thorax, the apex of the heart Abnormal • Murmurs Characterized by their location (over which valve they are the loudest), intensity (grade 1/6), frequency (harsh, blowing, musical, honking, or grunting), timing (point in the cardiac cycle the murmur is best heard), and quality (character/behavior). Rhythms Description of intensity • Ventricular premature contractions (VPCs) • • • • • Grade 1: barely audible and localized Grade 2: soft and localized, but easily auscultated Grade 3: moderate loudness and evident in more than 1 location Grade 4: loud with palpable thrill and radiates Grade 5: very loud with palpable thrill, audible with stethoscope barely touching thorax • Grade 6: very loud with palpable thrill, audible when the stethoscope is removed from the thorax • Gallop • Often seen during tachycardia when all four heart sounds are clearly heard. The combination of sounds is similar to the sound of a horse galloping. The rhythm is often heard with congenital heart disease, more specifically with hypertrophic cardiomyopathy in cats. • VPCs interrupt the normal sinus rhythm with a beat that is closer to the previous beat than normal followed by a compensatory pause. Patients often also have pulse deficits. • Atrial fibrillation • Rapid, but totally erratic rhythm with a clunking sound and varying intensity of the first and second heart sounds. Patients often have pulse deficits and variable pulse quality. Artifacts • Panting and excessive thoracic pressure in small patients similar to murmurs • Skin twitching similar to extra heart sounds • Friction from chest piece rubbing across fur similar to crackles Tip: Ventilation artifacts can be discouraged by holding the mouth shut, whistling, or briefly obstructing a nare. Purring may be controlled with a visual distraction (e.g., visualization of water, another animal), blowing short bursts in air in their face, picking up the cat, or gently pressing over the larynx. Tip: When locating heart valves, count the ribs from caudal to cranial. Tip: The pulse and heart beat should be auscultated together and be synchronous. A heart beat without a pulse is a pulse deficit and may indicate an arrhythmia. Note: See Figures 1.9–1.12, Circulation, pages 9–10, and color plates 1.9, 1.10, and 1.12, pages CP-1, 2. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 31 2 Skill Box 2.3 / Pulmonary Examination 2 Pulmonary Examination Technique • Begin the examination by observing the respiratory effort (quality) and pattern and any signs of respiratory distress (e.g., nostril flare, intercostal rib retraction). After the initial assessment, perform auscultation in a quiet room with a calm patient. Place the patient in a standing or sitting position. Avoid listening to recumbent patients as it leads to errors due to changes in thoracic conformation. Divide the thoracic cavity into quadrants to follow a sequential pattern. As each quadrant is auscultated, it is observed for respiratory rate and breath sounds. Rate • Canine: 10–30 breaths/min • Feline: 25–40 breaths/min Breath Sounds • Should be heard equally on both sides of the thorax. Breath sounds heard outside the location defined below can be indicative of a medical problem. The normal respirations of canines can be heard throughout inspiration and during the first 1/3 of expiration. Only during inspiration can normal lung sounds be heard in a cat. Normal • Bronchial: • Location: center of the chest cavity over caudal trachea and larger bronchi • Sound: intense and harsh sounds, full inspiratory and expiratory phase with a louder inspiratory phase • Bronchovesicular: • Location: surrounding the bronchial region • Sound: intermediate sounds representing a combination of bronchial and vesicular sounds, full inspiratory phase with a short and quieter expiratory phase. • Vesicular: • Location: periphery of thoracic cavity • Sound: softer sound (e.g., wispy, rustling of leaves), inspiratory phase is slightly longer and louder than expiratory phase. Abnormal • Stertor: • Location: larynx or trachea • Sound: discontinuous low-pitched snoring sound heard mainly on inspiration • Cause: tissue or secretions transiently obstruct airflow (e.g., elongated soft palate) • Stridor: • Location: larynx or thoracic inlet, referred sounds maybe heard throughout the thorax • Sound: intense continuous high pitched wheezes heard on inspiration • Cause: upper airway obstruction • Crackles (rales): • Location: over chest • Sound: discontinuous popping sound heard mainly on inspiration; defined as fine, medium, or coarse • Cause: fluid or exudate accumulation within airways or inflammation and edema in pulmonary tissue • Rhonchi or wheezes: • Location: isolated or variable • Sound: continuous musical sounds, low or high pitched heard at the end of inspiration or beginning of expiration; defined as high pitched or low pitched • Cause: ↓ airway lumen diameter Tip: Listen to the lung sounds before listening to heart tones because the ear is much less sensitive to softer sounds once it has adjusted to louder sounds. 32 SECTION TWO: PREVENTATIVE CARE Skill Box 2.4 / Abdominal Examination Abdominal Examination Technique • Gentleness when palpating an animal is essential as internal structures may be damaged if handled roughly. Structure descriptions can be: doughy (soft tissue that can be impressed with fingertips), firm (normal organ), hard (bones), fluctuant (soft, elastic, and undulates under pressure). Abnormalities noted on palpation are the following: pain, abnormal structures and their size, consistency, and shape, and location. • Large canine • Place the patient in a standing position. Stand on either side or to the rear. Place 1 hand on either side of the abdomen in a flat and relaxed position. Begin at the spine and gently and slowly move ventrally, allowing the abdominal viscera to slip through the fingers. Repeat this process throughout the abdomen moving caudal. • Small canine or feline • Place the patient in a standing position. Stand next to the patient. Cup 1 hand around the abdomen with the thumb on 1 side and the fingers on the other side in a flat and relaxed position. Begin at the spine and gently and slowly move ventrally, allowing the abdominal viscera to slip through the fingers. Repeat this process throughout the abdomen moving caudal. • Internal structure location • Cranial abdomen • Palpation of the liver, spleen, and the small intestines • Liver is difficult to palpate and extension past the costal arch may indicate hepatomegaly. • Spleen is difficult to palpate and recognition may indicate splenomegaly. • Normal stomach is rarely palpable, but with overeating (doughy or fluid-filled) or gastric distention it may be felt. • Mid-abdomen • Palpation of the small intestines, kidneys, and spleen • Right kidney is more cranial than the left kidney in cats and may be obscured by the ribs. • Mesenteric lymph nodes are difficult to palpate unless enlarged. • Caudal abdomen • Palpation of the colon, uterus, bladder, prostate, and small intestine • Feces can be discerned from a mass by its deformability with fingertip imprints. • Prostate can occasionally be palpated central to the colon and caudal to the bladder. Note: See Figures 1.6–1.8, Internal Organs, page 8, and Color Plates 1.6–1.8, pages CP-1. Skill Box 2.5 / Otoscopic Examination Otoscopic Examination Technique • Examine the good ear first to avoid spread of infection and to decrease resistance to examination of the possibly more painful ear. Begin with an otoscope with the appropriate sized cone for the patient. For ease of examination, the patient should be placed on a table or large canines should be placed in a sitting position. The head should be held in such a manner to avoid crushing the ear canal while directing the muzzle toward the thoracic inlet. Holding the pinna up and out from the base of the skull will allow straightening of the ear canal. Gently insert the otoscope into the external ear canal and slowly advance while observing the canal. As the cone enters the vertical canal, the pinna is pulled up and over the otoscope while the otoscope handle is rotated to a horizontal position. The tympanic membrane will then be visualized in a normal ear as a white translucent membrane. Any abnormalities such as: inflammation, redness, exudate, foreign objects, mites, or tumors should be noted. Note: See Figure 1.19, Ear, page 13. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 33 2 Skill Box 2.6 / Regional Lymph Node Examination 2 Regional Lymph Node Examination Technique • Three pairs of lymph nodes are routinely palpated in a normal animal; submandibular, prescapular, and popliteal. Axillary and inguinal nodes can often only be palpated with enlargement. Peripheral lymph nodes should be palpated simultaneously to evaluate symmetry. Enlarged nodes may be an initial indicator of a problem. Lymph nodes are generally smooth and oval in shape and can be most easily felt by grabbing the skin and allowing it to slip through the fingertips while pulling the hands away. • Submandibular • Location: ventral to the angle of the mandible, cranial to the parotid and submaxillary salivary glands • Size: group of 2 or 3 nodes pea to grape size • Prescapular (superficial cervical) • Location: in front of the cranial border of the scapula • Size: group of 2 or 3 nodes slightly larger than submandibular nodes • Popliteal • Location: caudal to the stifle • Size: 1 node about the size of a pea; not always palpable in smaller animals • Axillary • Location: caudal and medial to the shoulder joint • Size: 1 or 2 nodes; not palpable in normal animals (0.5–10 mm) • Inguinal • Location: furrow between the abdominal wall and the medial thigh • Size: 2 nodes, not palpable in normal animals (0.5–10 mm) Note: See Figure 1.2, Regional Lymph Nodes, page 6. Skill Box 2.7 / Neurologic Examination Neurologic Examination Technique • The neurologic examination begins as the patient walks into the examination room. Notice should be paid to the patient’s body posture (e.g., head tilt), attitude (e.g., demented, semicomatose, disoriented) and gait (e.g., inability or abnormal walk, dragging limbs, circling), purposeful movement (e.g., attempt to move down limbs), and palpation (e.g., symmetry, worn toenails, ↑ or ↓ muscle tone, masses). Postural Reactions Spinal Reflexes • The patient’s ability to recognize an abnormal position and change its position to bear weight and be able to walk. All levels of the nervous system are evaluated, but lesion localization is not possible. • Deficits in spinal reflexes alert to a problem along the nerve pathway; receptor, sensory nerve, efferent nerve, and skeletal muscles. Responses seen may be normal, absent, depressed or exaggerated. • Extensor postural thrust • Anal sphincter reflex • While supporting the patient under the thorax, as the hindlimbs touch the floor, monitor for symmetric caudal walking motions. • Hemistanding/hemiwalking • A hindlimb and front limb of the same side are lifted, monitor for lateral walking movements. 34 SECTION TWO: PREVENTATIVE CARE • Perineal stimulation with a needle or forceps; monitor for contraction of the anal sphincter muscle. • Panniculus reflex • Pin prick stimulus to skin over the back; monitor for twitching of cutaneous trunci muscles on both sides. Skill Box 2.7 / Neurologic Examination (Continued) • Hopping • While supporting the patient, 3 limbs are lifted and the patient is moved medially and laterally, monitor for initiation and movement of hopping. • Placing • While supporting the patient under the thorax, the thoracic limbs are brought in contact with the edge of a table; immediate placement of the limbs on top of the table is expected. • This is done twice, once with the eyes covered and once with the eyes opened. • Proprioceptive positioning • While supporting the patient, turn the hind foot over onto the dorsal surface and monitor the length of time to turn it back to a normal position, if even able. • Wheelbarrowing • While supporting the patient under the abdomen with the hindlimbs lifted, monitor the length of time to start walking forward and the walking coordination. Hindlimb Reflexes • Cranial tibial response • Percuss muscle belly; monitor for flexion of the hock. • Crossed extensor reflex • Pinch digits of down limb; monitor for involuntary movement of upper limb. • Gastrocnemius reflex • Percuss Achilles tendon; monitor for extension of the hock. • Patellar reflex • Patient in lateral recumbency and stifle gently supported in a flexed position, percuss patellar tendon; monitor for extension of the stifle. • Sciatic response • Percuss thumb in the sciatic notch; monitor for jerk of the entire limb. • Withdrawal • Patient in lateral recumbency. pinch digits; monitor for flexion of the limb and pain recognition. Front Limb Reflexes • Extensor carpi radialis response • Percuss the extensor carpi radialis muscle; monitor for extension of the carpus. • Triceps reflex • Patient in lateral recumbency with limb supported, elbow fully extended and leg caudal, percuss the triceps tendon: monitor for slight extension of the elbow. • Withdrawal • Patient in lateral recumbency, pinch digits; monitor for flexion of the limb and pain recognition. Sensory Evaluation Cranial Nerves • Evaluation of deep pain perception • Hyperpathia • Pressure is applied along the thoracic and lumbar regions to the spine and muscles at each vertebra; monitor for a behavioral response to pain • Sensory level • Pin prick stimulus to skin over the back, monitor for behavioral response • The following cranial nerves (CN) are evaluated with a suspected brain lesion • Optic nerve (CN II): vision, menace response • Oculomotor nerve (CN III): pupillary light response, size and symmetry • Trochlear nerve (CN III, IV, VI): eye movements • Trigeminal nerve (CN V, VII): muscle mass, jaw tone, facial movements, blinking, lip retraction • Vestibulocochlear nerve (CN VIII): hearing • Glossopharyngeal and vagus nerves (CN IX, X, XI): pharyngeal sensation, gag response • Hypoglossal nerve (CN XII): tongue movement and strength CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 35 2 Skill Box 2.8 / Orthopedic Examination 2 Orthopedic Examination Technique • Similar to the neurologic examination, the orthopedic examination begins as the patient enters the examination room. Notice should be paid to the patient’s conformation, stance, sitting, standing, rising and gait. The examination should continue with a hands-on evaluation of the area of concern, including the alternate side. A systematic approach should be used to cover the entire limb, often beginning distally and moving proximal. Alterations in range of motion and rotation should be noted along with any crepitus, clicking, clunking, instability, swelling, muscle atrophy or overdevelopment, and pain. Begin the examination by evaluating the nonaffected joint to assess the patient’s normal response to manipulation and pressure. Stifle Pelvis • Cranial drawer motion • Barden’s procedure • Patient in lateral recumbency, 1 hand stabilizes the femur proximal to the stifle. The second hand is placed with the thumb behind the fibular head and the index finger over the tibial crest. With the femur stabilized, the second hand moves the tibia cranial and distal in a plane parallel to the tibial plateau. Monitor for the tibia sliding cranially or caudally in relationship to the femur indicating cruciate ligament rupture or partial tear. • Test should be performed with the stifle joint in extension, 90º flexion, and normal standing position. • Tibial compression test • Limb is held in a standing position, the hock is flexed to tense the gastrocnemius muscle which compresses the femur and tibia together; monitor for forward motion of the tibia in a ruptured cranial cruciate ligament. • Patellar luxation, medial • Limb is held extended with the foot rotated internally, digital pressure is applied medially; monitor for medial displacement indicating luxation. • Patellar luxation, lateral • Limb is held slightly flexed with the foot rotated externally, digital pressure is applied laterally; monitor for lateral displacement indicating luxation. • Patient in lateral recumbency, grasp the femur with 1 hand. Place the thumb of second hand on the greater trochanter of the femur, while resting the rest of your palm on the pelvis. With gentle pressure, attempt to lift the femur, keeping it parallel to the table. Monitor for subluxation of the femur through the thumb on the greater trochanter indicating hip laxity. • Barlow’s sign • Patient in dorsal recumbency with stifle flexed, the left hand is placed on the right stifle and slowly adducted, monitor for luxation of the femoral head from the acetabulum indicating joint capsule stretching. • Hip luxation • Patient in a standing position, place the thumb in the space caudal to the greater trochanter, externally rotate the femur; monitor for the trochanter to roll over the thumb indicating luxation. • Ortolani maneuver, lateral recumbency • Limb is held in a standing position parallel to the table surface. One hand is placed over the hip joint, the other hand cups the stifle joint to apply pressure pushing the femoral head in a dorsal direction in relation to the acetabulum. Monitor for hip subluxation indicating hip laxity. • Ortolani maneuver, dorsal recumbency • Stifles are positioned parallel to each other and perpendicular to the table. Downward pressure is applied on the stifles to subluxate the hip. Maintain pressure and abduct the stifle. Monitor for hip subluxation indicating hip laxity. 36 SECTION TWO: PREVENTATIVE CARE VACCINATIONS Young animals receive a small amount of natural immunity from their mother’s milk, exchanged in the form of colostrum, during the first few days of nursing. However, this temporary maternal protection wanes by 6–9 weeks. To continue and enhance this protection, vaccinations are available to protect the animal from contracting various highly contagious diseases. These diseases and their corresponding vaccinations are charted on the following pages. Vaccines in general are meant to be stored in the refrigerator, and need to be shaken well before dispensing. Lyophilized vaccines should be used within 30 minutes of reconstitution. Heat, excessive cold, and light exposure can inactivate the vaccine and make them ineffective. Guidelines to Follow When Vaccinating an Animal • A complete physical examination and health evaluation are given by a veterinarian before any vaccination. Adverse reactions: As with the administration of any drug, vaccines can result in adverse reactions. Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, lethargy, and anaphylactic shock (vomiting, salivation, dyspnea, and incoordination). Precautions should be taken in animals with a history of vaccine reactions. Vaccines should be avoided if possible, but if they must be given the following guidelines should be observed: • A vaccine from a different manufacturer • Premedication with diphenhydramine and prednisolone sodium succinate 30 minutes prior to the vaccination • Hospital observation for the day Clients should be educated to monitor vaccination sites for lump formation and contact their veterinarian if found. Biopsies should be taken following the AAFP guidelines: • Present for 3 months • Do not vaccinate pregnant animals with a modified live vaccine. • ≥2 cm in diameter • Animals with a fever or in debilitated health should not be vaccinated until healthy. • ↑ Size after 1 month As a constant effort to increase patient bonding and improve client satisfaction, special steps can be taken to ensure patient and owner comfort. Taking the extra steps to make this a more enjoyable experience will benefit both the patient and staff in future visits. A few tips for making injections a more comfortable procedure include: • Allowing the vaccine to warm to room temperature • Changing needles before injection; use of a 25-gauge needle • Gently squeezing or flicking the injection site to dull the area • Distracting the patient (e.g., treats, sliding the patient across the table or lifting their front legs, twitching a ear or tapping the nose, talking to the patient). Titers: The discussion of vaccine titers has become very popular in veterinary medicine, and continues to remain controversial. Titers are available from various laboratories for distemper, parvovirus, rabies, and panleukopenia. If a titer is high, it is accepted as providing protection; however a low titer result does not reflect the immunization of an animal. Titers are best used following the puppy vaccine series to ensure proper levels of immunity have been reached. As each animal and its environment are unique, vaccine recommendations will vary accordingly at the discretion of the veterinarian and in accordance with state laws. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 37 2 Table 2.6 / Canine Transmissible Diseases: Coronavirus, Distemper Distemper Definition Contagious viral disease affecting the GIT, resulting in sporadic outbreaks of vomiting and diarrhea. Diarrhea is caused by the virus invading the enterocytes of the villous tips. An acute to subacute febrile and often fatal, highly contagious viral disease with respiratory, GIT, and central nervous system (CNS) manifestations. Presenting Clinical Signs • Most infected dogs are asymptomatic and less signs are exhibited in adult dogs • Anorexia, depression, diarrhea (yellow-green to orange, malodorous) and vomiting • Mucosal phase: malaise, nasal discharge followed by pneumonia, vomiting, diarrhea and fever • CNS phase: seizures, circling, pacing, ataxia and paresis Examination Findings • Dehydration, mild respiratory effects • Abdominal pustules, anterior uveitis, conjunctivitis, dental enamel hypoplasia, hyperkeratosis of foot pads, KCS, myoclonus, optic neuritis, retinal degeneration and rhinitis General • History/clinical signs • History/clinical signs Laboratory • Electron microscope • Fluorescent antibody tests • CBC: lymphopenia, leukopenia, thrombocytopenia in early disease • Fluorescent antibody test: detection of virus in intact cells (e.g., conjunctival scrapings, buffy coat, urine sediment, CSF, transtracheal wash) • IgM: serum antibodies measured by ELISA • IgG: serial titers on 2 serum samples 2 weeks apart to detect ↑ titers • PCR: virus detection in respiratory secretions, CSF, feces and urine Imaging • N/A • Thoracic: interstitial or alveolar pneumonia Procedures • N/A • N/A General • Symptomatic • Supportive • Fluid therapy • Supportive • Fluid therapy Medication • Imodium • • • • Antibiotics B vitamin supplementation Anticonvulsant therapy Antiemetics Nursing Care • N/A • • • • • Humidification of airways; nebulization and coupage Clean discharge from eyes and nose Nutritional support Adequate fluid intake or therapy Isolation to avoid infecting other patients Diagnosis Presentation Coronavirus Treatment 2 Disease 38 SECTION TWO: PREVENTATIVE CARE Table 2.6 / Canine Transmissible Diseases: Coronavirus, Distemper (Continued) Follow-Up Disease Coronavirus Distemper Patient Care • N/A • Monitor dehydration and electrolytes. • Recheck thoracic radiographs if persistent cough. Prevention/Avoidance • Vaccinate • Clean up feces: Will be shed in the feces for typically 6–9 days; but can be for many months • Vaccinate • Avoid infected dogs or wildlife. • Clean up feces: shedding time typically < 2–3 months Complications • Persistent diarrhea for 10–12 days • Dehydration and electrolyte imbalances • Occurrence of CNS signs may appear for up to 2–3 months after clinical signs • Seizures or CNS signs Prognosis • Complete recovery expected • Ranges from subacute to mortality • Mortality rate of 50% • Optional part of vaccine series • Consider vaccinating high-risk dogs: field trial dogs and kenneled dogs • Transmitted by fecal-oral route • Unvaccinated puppies 6–12 weeks of age are most at risk. • Transmitted through body secretions, body excretions, and airborne • Easily destroyed by heat and most disinfectants; survives no more than a few days outside the host • Recovered dogs are not carriers. • Incubation period: 1–5 weeks Notes 2 Table 2.7 / Canine Transmissible Diseases: Hepatitis, Infectious Tracheobronchitis Hepatitis Infectious Tracheobronchitis Definition Viral disease caused by adenovirus type 1. Affects the liver, eyes, and endothelium Contagious respiratory disease often caused by the bacteria Bordetella bronchiseptica resulting in the harsh, hacking coughing. It can also be caused by the viruses parainfluenza and canine adenovirus 2. Presenting Clinical Signs • Coma, depression, diarrhea, disorientation, lethargy, seizures, stupor, vomiting • Mild form: repetitive dry-sounding hacking cough (referred to as “seal-like”) often followed by gagging and mild serous naso-ocular discharge • Severe form: anorexia, depression, naso-ocular discharge and productive cough Examination Findings • Abdominal pain, anterior uveitis, corneal edema, fever, hemorrhagic diathesis, hepatic encephalopathy, hypoglycemia, pale mucous membranes, nonsuppurative encephalitis, tonsillitis-pharyngitis • Fever Presentation Disease CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 39 Table 2.7 / Canine Transmissible Diseases: Hepatitis, Infectious Tracheobronchitis (Continued) Disease Diagnosis 2 Hepatitis Infectious Tracheobronchitis General • Clinical signs • Cough easily elicited on palpation of trachea • History of frequenting boarding facilities or off-leash parks Laboratory • • • • • CBC: mild leukopenia, neutrophilic leukocytosis with a left shift • Cultures of nasal swabs, transtracheal or bronchial washings: Bordetella and Mycoplasma • PCR: virus detection Imaging • Radiographs, abdominal: hepatomegaly • Ultrasound: hepatomegaly and abdominal effusion • Abdominal, thoracic: severe form, interstitial density, and alveolar pattern General • Symptomatic • Supportive • Fluid therapy +/− potassium and dextrose supplementation • Supportive Medication • Antibiotics for secondary pneumonia or pyelonephritis • Antibiotics • Bronchodilators • Antitussives Nursing Care • Frequent feedings to avoid hypoglycemia • Restricted activity/cage rest • • • • • • Patient Care • Monitor blood chemistries • Monitor dehydration, acid-base balances, body weight, physical assessment, and electrolytes • Adequate fluid intake • Airway humidification • Strict rest for 14–21 days Prevention/Avoidance • Vaccinate • Avoid urine contact: shedding time, 6 months or more • • • • Complications • • • • • N/A Prognosis • Guarded to good • Some with a complete recovery • Complete recovery expected unless severe disease develops • Transmitted through oronasal exposure and shed in all secretions during acute infection • Shed for 6–9 months following recovery • Highly resistant to inactivation and disinfection, thus enabling spread by fomites and ectoparasites • Highly contagious via aerosol spread and fomites • Disinfect with bleach, Nolvasan, or Roccal. • Incubation period: 3–10 days CBC: neutropenia, lymphopenia and thrombocytopenia Chemistry panel: ↑ AST, ALT and ↓ glucose Bile acids: mild to moderately high Coagulation tests: prolonged PT, APTT, hypofibrinogenemia Follow-Up Treatment Procedures Notes 40 Hepatic failure or chronic active hepatitis Acute renal failure DIC Glaucoma SECTION TWO: PREVENTATIVE CARE Encourage outpatient care for uncomplicated disease. Airway humidification Strict confinement with low stress, and few dogs Nutritional support ↑ Fluid intake Fresh air flow Vaccinate Prevent fomite spread with bleach diluted 1:32. Isolate infected animals. Shed for up to 3 months, infectious risk is greatly ↓ after recovery of discharge and cough. Table 2.8 / Canine Transmissible Diseases: Leptospirosis, Lyme Disease Leptospirosis ZOONOTIC Lyme Disease ZOONOTIC Definition Acute and chronic bacterial disease affecting lungs, kidneys, and liver A multiorgan disease caused by the spirochete Borrelia burgdorferi Presenting Clinical Signs • Anorexia, dehydration, depression, myalgia, reluctance to move and vomiting • Anorexia and lethargy Examination Findings • Acute renal or hepatic failure, conjunctivitis, DIC, epistaxis, fever, melena, petechia, poor capillary perfusion, rapid irregular pulse, tachypnea • Fever, lymphadenopathy, and polyarthritis General • Clinical signs • Joint palpation: lameness, swelling, and pain • History of travel in known tick infested areas Laboratory • CBC: leukopenia, thrombocytopenia, and neutrophilia with left shift • Chemistry panel: ↑ BUN, creatinine, AST, ALT, ALP, bilirubin, phosphorus, ↓ chloride, sodium, and potassium • Urinalysis: proteinuria, pyuria, bilirubinuria, and isothenuria • Microscopic agglutination test: + after 1 week, peaking at 3–4 weeks, fourfold rise in titer • Combined IgM-IgG ELISA titers: IgM is + in first week and persists to 2 weeks; IgG is + 2–3 weeks after infection and persists for months • • • • Imaging • N/A • Radiographs, joints: +/− effusion Procedures • N/A • N/A General • Supportive • Fluid therapy • Transfusion therapy • Supportive Medication • Antibiotic: doxycycline, penicillin (leptospiremia) • Antibiotics: tetracycline, ampicillin, doxycycline, and cephalexin • NSAIDs Nursing Care • Restrict activity/cage rest. • Nutritional support • Encourage outpatient care. • Pain management Treatment Diagnosis Presentation Disease IDEXX SNAP 3Dx test IDEXX SNAP 4Dx test IFA and ELISA: ≥1:152 = highly + Synovial fluid analysis: suppurative and +/− Borrelia organisms within WBC CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 41 2 Table 2.8 / Canine Transmissible Diseases: Leptospirosis, Lyme Disease (Continued) Disease Follow-Up 2 Leptospirosis ZOONOTIC Lyme Disease ZOONOTIC Patient Care • Monitor blood chemistries and urinalysis. • Restricted activity Prevention/Avoidance • Vaccinate in high-risk areas. • • Avoid water sources where animals may have urinated; shedding time, months • to years. • • Complications • DIC • Permanent renal and hepatic dysfunction • CNS disorders • Fatal renal failure • Heart block (rare) Prognosis • Most infections are subclinical; those that are acutely severe have a guarded prognosis. • Recovery expected, but recurrence possible within weeks to months • Spread in the urine of recovered animals for months to years following infection • Transmitted by food, water, bedding, soil, vegetation, or fomites • Disinfect with povidine-iodine; bleach 1:10 dilution. • Enters through skin or mucous membranes or by ingestion of contaminated water • Onset is a few days to 30 days; typically 3–14 days. • Transmitted most commonly by the deer tick Ixodes dammini through a tick bite. • Infected animals pose little risk to humans; they are more of a risk in passing ticks to humans. Notes Limit access to tick-infested areas. Use tick repellants/insecticides. Periodically check dogs for ticks. Vaccinate in high-risk areas. Table 2.9 / Canine Transmissible Diseases: Parvovirus, Rabies Parvovirus (CPV) Rabies ZOONOTIC Definition Highly contagious disease causing severe enteritis and affecting the lymphatic system. Typically affects puppies between weaning and 6 months of age. A virus that can infect almost all warm-blooded animals and is considered untreatable. It infects the nervous system, causing death from paralysis. Presenting Clinical Signs • Anorexia, depression, and vomiting • Diarrhea: profuse, liquid, hemorrhagic, and distinct metallic odor • Symptoms may vary in older dogs. Three phases • Prodromal phase (2–3 days): fever, subtle behavior changes • Furious phase (2–4 days): irritability, restlessness, barking, ataxia, and seizures • Paralytic phase (2–4 days): paralysis, depression, coma, and death from respiratory paralysis Examination Findings • Extreme dehydration, fever • Prodromal phase: slow corneal and palpebral reflexes Presentation Disease 42 SECTION TWO: PREVENTATIVE CARE Table 2.9 / Canine Transmissible Diseases: Parvovirus, Rabies (Continued) Parvovirus (CPV) Rabies ZOONOTIC General • History/clinical signs • History/clinical signs Laboratory • CBC: severe leukopenia and lymphopenia, PCV variable • Chemistry panel: ↑ bilirubin, ALT, AST and ↓ potassium, sodium and chloride • ELISA assay • IDEXX Parvo Antigen SNAP test • Fecal hemagglutination test • CSF: minimal ↑ protein and leukocytes • Postmortem virus isolation from fresh brain tissue Imaging • Radiographs, abdominal: gas and fluid distention in GIT • Often causing a misdiagnosis of GIT obstruction • N/A Procedures • N/A • N/A General • Symptomatic • Supportive • Fluid therapy: aggressive • Supportive Medication • Antibiotics: ampicillin and gentamicin • Antiemetics: metoclopramide or H2 blocker • N/A Nursing Care • Nothing by mouth for 24 hours after vomiting and severe diarrhea • Quarantine protocol • Strictly inpatient/quarantine • Runs and cages should be locked. Patient Care • Dogs should remain isolated for 1 week after complete recovery. • None Prevention/Avoidance • Vaccinate out to 16–18 weeks • Isolate puppies as much as possible until vaccine series has been completed. • Vaccinate • Strict quarantine for those suspected of having rabies • Euthanize all animals known to have rabies Complications • Septicemia • Secondary bacterial pneumonia • Intussusception • N/A Prognosis • Survival of 3–4 days is usually followed by rapid recovery. • Immunity by natural infection is lifelong if the dog survives. • Almost 100% fatal • Transmitted by the fecal-oral route, saliva, vomitus, or direct contact • Stable in the environment for months to years • Rottweilers, Doberman Pinschers, Pit Bull Terriers, and Labrador Retrievers seem to be at higher risk. • Disinfect with 1:32 dilution of bleach and water or Parvocide®. • Incubation period 5–10 days • Transmitted in the saliva • Inactivated by disinfectants • Head should be chilled on wet ice (do not freeze) and sent to a lab for analysis. Follow-Up Treatment Diagnosis Disease Notes CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 2 43 Table 2.10 / Canine Vaccination Protocol The site of vaccine injection varies between clinics, but it is important to have a designated location for each vaccine and to note these locations in each patient’s chart. Vaccines are routinely given subcutaneously, except for the intranasal version of Bordetella. Vaccine ≤16 Weeks of Age >16 Weeks of Age Vaccine Classificationa DHPP • Canine distemper (D) • Canine hepatitis/adenovirus (H) (CAV-2) • Canine parainfluenza (P) • Canine parvovirus (P) • 1 dose at 6–9 weeks, then repeat every 3–4 weeks until 16 weeks (e.g., 1 dose at 8, 12 and 16 weeks) • 1 dose at 12 months, then every 3 years • 1 dose initially • 1 dose 12 months after initial, then 1 dose every 3 years Core Core Leptospirosis • Canine leptospirosis • 1 dose: 12 and 16 weeks • Annually dependent on patient’s risks • 2 doses, 2–4 weeks apart • Annually dependent on patient’s risks Noncore Bordetella • Infectious tracheobronchitis • IN: 1 dose at 3–12 weeks, then 1 dose 2–4 weeks later, then biannually or annually dependent on patient’s risks • SQ: 1 dose at 6–8 weeks, repeat 1 dose 2–4 weeks later, then annually dependent on patient’s risks • IN: 2 doses, 2–4 weeks apart, then biannually or annually dependent on patient’s risks • SQ: 1 dose, then biannually or annually dependent on patient’s risks Noncore Rabies • Rabies virus • 1 dose at 12–16 weeks • 1 dose every 1–3 years dependent on vaccine type and state requirements • 1 dose initially • 1 dose every 1–3 years dependent on vaccine and state requirements Core Lyme • Lyme borreliosis • 1 dose at 9–12 weeks, then repeat 2–4 weeks later • Annually, dependent on patient’s risk • 2 doses, 2–4 weeks apart • Annually, dependent on patient’s risk Noncore Noncore Core Note: Injection site, age at administration, and booster protocol may vary depending on the manufacturer of the vaccination and veterinarian’s discretion. Recommendations by the individual manufacturer should be followed. The frequency may vary depending on the state’s requirements and the veterinarian’s protocol. Note: Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, and lethargy to anaphylactic shock (vomiting, salivation, dyspnea, and incoordination). a Core vaccines are those recommended to every dog. Noncore vaccines are recommended based on potential risk factors. Table 2.11 / Feline Transmissible Diseases: Feline Calcivirus Disease Feline Calicivirus (FCV) Definition One of the major causes of feline upper respiratory disease. An acute, highly contagious viral disease causing oral ulceration, pneumonia, and occasionally arthritis. Presentation 2 44 Presenting Clinical Signs Anorexia, depression, dyspnea, mild conjunctivitis, mild sneezing, nasal discharge, ulcerated tip of nose Examination Findings • +/− Arthralgia, enteritis, facial and limb edema, fever, gingivitis, limping syndrome, interdigital paw ulcers, oral ulcers SECTION TWO: PREVENTATIVE CARE Table 2.11 / Feline Transmissible Diseases: Feline Calcivirus (Continued) Follow-Up Treatment Diagnosis Disease Feline Calicivirus (FCV) 2 General • History/clinical signs Laboratory • CBC: neutrophilia and lymphopenia • Chemistry panel: ↑ bilirubin, CK • Virus isolation: cell cultures of swabs from oropharynx, lung tissue, nasal cavity, conjunctiva, feces, and blood Imaging • Radiographs, thoracic: generalized ↑ density of the lungs Procedures • N/A General • Self-limiting in 5–7 days • Supportive Medication • • • • • Nursing Care • Oxygen supplementation if complicated pneumonia • Nutritional support Patient Care • • • • • Prevention/Avoidance • Vaccinate • Prevent contact with FCV-infected cats. • Virus is shed continuously. Complications • Interstitial pneumonia • Secondary bacterial infections Prognosis • Excellent unless pneumonia develops • Recovered cats may shed the virus in their saliva for long periods. Notes Antibiotics: amoxicillin Antibiotic (ophthalmic) Pain medication Immunostimulants: interferon Corticosteroids Keep eyes and nose clear of discharge. Support nutrition and fluid intake Airway humidification Provide soft foods if oral ulcers. Irrigate oral lesions with 0.2% chlorhexidine solution. • Transmission is through direct contact and fomites; virus is shed in oropharyngeal, conjunctival, and nasal secretions, feces, sloughed hair and skin. • Very resistant virus; disinfect with 1:32 dilution of bleach water. • Cats that recover may remain subclinical carriers for months to years. • Cats should be tested for FIV or FeLV to rule out underlying immunodeficiency syndromes. • Occurs with FHV-1 in most cases. • Incubation period is 1–5 days. • Intermittent shedding may take place for 4 months postinfection. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 45 Table 2.12 / Feline Transmissible Diseases: Feline Infectious Peritonitis Definition A systemic viral disease with high mortality. This disease arises from a mutation of a benign virus, feline enteric coronavirus (FEVC) commonly found in the GIT of cats. There are 2 different forms: wet/effusive form and the dry/noneffusive, granulomatous form. Presenting Clinical Signs • Ataxia, behavioral changes, depression, diarrhea, failure to grow, inactivity, paresis, poor condition, seizures, urinary incontinence, vomiting, weight loss • Dry Form: dyspnea, exercise intolerance • Wet Form: abdominal distention Examination Findings • Fever, icterus, pallor • Dry form: anterior uveitis, chorioretinitis, iritis, irregular pupils, tumors • Wet Form: abdominal or pleural effusion General • Clinical signs after other conditions have been ruled out Laboratory • • • • • • • Imaging • Radiographs, thoracic: effusion • Radiographs, abdominal: effusion, organomegaly, lymphadenopathy, and ileocolic mass Procedures • Abdominocentesis or thoracocentesis; straw-colored fluid, viscous, clots, fibrinous, and ↑ protein • Tumor biopsy: granulomatous inflammation General • Therapeutic paracentesis • Fluid therapy • Supportive Medication • Corticosteroids: prednisone • Immunosuppressive drugs: cyclophosphamide • Immunostimulants: immunoregulin, interferon, acemannan Nursing Care • Nutritional support Diagnosis Presentation Feline Infectious Peritonitis (FIP, Feline Coronavirus) Treatment 2 Disease 46 SECTION TWO: PREVENTATIVE CARE CBC: leukopenia (early in disease), leukocytosis with neutrophilia, lymphopenia (late in disease), nonregenerative anemia Chemistry panel: ↑ bilirubin, ALP, ALT, globulins and bile acids, BUN, creatinine Urinalysis: ↓ bilirubin and protein Histopathologic examination: biopsy is the only definitive method for FIP diagnosis Immunohistochemistry: most accurate FIP virus detection on biopsied tissue Titers: limited value, highest titers have ↑ likelihood of disease PCR: virus detection Table 2.12 / Feline Transmissible Diseases: Feline Infectious Peritonitis (Continued) Follow-Up Disease Feline Infectious Peritonitis (FIP, Feline Coronavirus) Patient Care • Confine to prevent exposure to other cats Prevention/Avoidance • • • • Complications • GIT obstruction • Neurologic disease • Pleural effusion Prognosis • Almost 100% mortality • Length of disease is a few days to months. Notes 2 Prevent contact with FIP-positive cats; transmission is rare between cats. Intranasal vaccine; very low efficacy Routine disinfection Control and prevent feline leukemia virus (FeLV) infection. • Transmitted through oral and respiratory secretions, feces, urine, and fomites, but most commonly through the mutation of FECV to FIP • Survives in the environment for several weeks • Readily inactivated by commonly used disinfectants Table 2.13 / Feline Transmissible Diseases: Feline Panleukopenia Virus, Feline Immunodeficiency Virus Feline Panleukopenia Virus (FPV, Feline Parvovirus) Feline Immunodeficiency Virus (FIV) Definition An acute, systemic, and enteric viral disease. It has a sudden onset, is highly contagious, and has a high mortality rate. An immunodeficiency syndrome characterized by chronic and recurrent infection. Gradually selecting and destroying T-lymphocytes. This process makes cats more prone to secondary syndromes. Affected cats can be asymptomatic for >5years. Presenting Clinical Signs • Abdominal pain (crouching position and head between front paws), anorexia, depression, diarrhea, persistent vomiting, rough and dull hair coat Stage 1 • Usually subclinical: fever, neutropenia, and lymphadenopathy Stage 2 • Latent phase: could last for years Stage 3 • Terminal phase: abscesses, anorexia, cachexia, dementia Examination Findings • Fever progressing to hypothermia and progressive dehydration • Conjunctivitis, gingivitis, otitis, periodontitis, pneumonia, rhinitis, skin infections, stomatitis, tachycardia, urinary tract infections Presentation Disease CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 47 Table 2.13 / Feline Transmissible Diseases: Feline Panleukopenia Virus, Feline Immunodeficiency Virus (Continued) Disease Feline Immunodeficiency Virus (FIV) General • History/clinical signs • History/clinical signs of exposure Laboratory • CBC: leukopenia • Chemistry panel: ↑ BUN, creatinine, and electrolyte imbalances • Virus isolation: feces • CITE test for canine parvovirus: detects FPV antigen in the acute stage • Serologic testing: rising titers • Chromatographic test strip, feces: + for FPV and CPV • • • • • • Imaging • N/A • N/A Procedures • N/A • N/A General • Supportive • Fluid therapy • Blood transfusions • Symptomatic • Fluid therapy • Dental care Medication • Antibiotics • Antiemetics: metoclopramide • • • • Nursing Care • Nothing by mouth until vomiting and diarrhea subside • Heat support if hypothermic • Monitor hydration, electrolytes, and CBC • Nutritional support Patient Care • Heat support • Nutritional support once eating • Maintain current vaccines to prevent infection of respiratory disease Prevention/Avoidance • Vaccinate. • Prevent contact with infected cats. • Clean up feces: shedding time up to 6 weeks • • • • Complications • • • • • N/A Prognosis • Poor prognosis in terminal phase: ≤1 year survival • >50% remain asymptomatic within 2 years after diagnosis • Poor prognosis in terminal phase: ≤1 year survival • Transmitted by fomites and through all body secretions for up to 6 weeks. • Disinfect with 1:32 dilution of bleach water. • Survives months to years in the environment • In utero transmission from infected queen leads to cerebellar hypoplasia in kittens. • Incubation period: <14 days • Recovered cats have lifetime immunity against FPV. • • • • • Follow-Up Treatment Diagnosis 2 Feline Panleukopenia Virus (FPV, Feline Parvovirus) Notes 48 Hypothermia and shock DIC Mycotic infection Jaundice SECTION TWO: PREVENTATIVE CARE CBC (stage 3): anemia (v), lymphopenia, neutropenia Chemistry panel: ↑ protein and globulins Urinalysis: ↑ protein ELISA: + Western blot: confirms + results of ELISA Culture, plasma, saliva, tears, urine: FeLV isolated and identified Antibiotics for secondary infection: metronidazole Appetite stimulants: cyproheptadine, diazepam Corticosteroids: prednisone Immune stimulants: interferon, zidovudine, ddC, PMEA, staphylococcal protein A, Propionibacterium acnes, acemannan Isolate affected cats. Neuter males. Quarantine and test incoming cats. Retest high-risk cats regularly. Transmitted through bite wounds, in utero, and transfusions Theoretically transmitted through intimate contact or fomites Shed in the saliva Most commonly seen in unneutered roaming males A kitten may test + when <6 months old due to maternal antibodies: retest at 8–12 months after all maternal antibodies are gone. Table 2.14 / Feline Transmissible Diseases: Feline Leukemia Virus, Feline Rhinotracheitis Virus Feline Leukemia Virus (FeLV) Feline Rhinotracheitis Virus (FHV-1, Feline Herpesvirus) Definition A retrovirus causing immunosuppression and various types of cancer, specifically lymphoma and leukemia. Cats may clear initial infection, but there is no cure for persistent infection, which ultimately leads to death. One of the major causes of feline upper respiratory disease. A highly contagious viral disease causing rhinitis, conjunctivitis, and ulcerative keratitis. Presenting Clinical Signs • Persistent diarrhea and wasting • Anorexia, cough (rare), depression, excessive lacrimation, hypersalivation, loss of voice, nasocular discharge, photophobia, sneezing Examination Findings • Conjunctivitis, fever, gingivitis, keratitis, lymphadenomegaly, periodontitis, rhinitis, skin infections, stomatitis • Fever, conjunctivitis, herpetic ulcers, rhinitis, ulcerative keratitis General • History/clinical signs • Clinical signs Laboratory • CBC: lymphopenia, neutropenia, nonregenerative anemia, thrombocytopenia, and immune-mediated hemolytic anemia • ELISA: virus antigen detection • Bone marrow aspirate or biopsy • IFA test: + • CBC: transient leukopenia, leukocytosis • Virus isolation: cell cultures of swabs from the pharynx, nasal epithelium, or conjunctiva • IFA: viral detection • Stained conjunctival smears: intranuclear inclusion bodies detection Imaging • N/A • Radiographs, skull: chronic disease shows changes in the nasal cavities and frontal sinuses Procedures • N/A • N/A General • Symptomatic • Supportive • Fluid therapy Medication • Antibiotics, esp. with Haemobartonella infection • Immunomodulatory drugs: interferon • • • • • Antibiotics: amoxicillin and enrofloxacin Antibiotics (ophthalmic) Antiviral eye medications: Vira-A Immunomodulatory drugs: interferon Lysine Nursing Care • Blood transfusions; many may be necessary. Using blood from FeLVvaccinated cats may reduce the level of FeLV antigenemia in some cats. • • • • Nutritional support, feeding tube placement Keep eyes and nose clear of discharge. Airway humidification ↑ Environmental temperature; herpesvirus is temperature sensitive Treatment Diagnosis Presentation Disease CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 2 49 Table 2.14 / Feline Transmissible Diseases: Feline Leukemia Virus, Feline Rhinotracheitis Virus (Continued) Disease Feline Leukemia Virus (FeLV) Feline Rhinotracheitis Virus (FHV-1, Feline Herpesvirus) Patient Care • Symptomatic • Nutritional support, low stress environment, management of secondary conditions • Confine indoors to decrease environmentally induced stress. Prevention/Avoidance • Vaccinate outdoor cats and those living with a FeLV-positive cat. • Quarantine and test all new cats to the household or local environment. • Prevent contact with FeLV-positive cats. • Vaccinate. • Prevent contact with FHV-infected cats. • Virus shed intermittently Complications • • • • • • • • • Prognosis • >50% of cats die from related diseases in 2–3 years • Good; 7–10 days • All FeLV-positive cats must remain indoors to prevent further spread of the disease. • Test each cat prior to first vaccine or if there has been a long period of time without vaccines. • More false-positive cats when using whole blood on the ELISA test • False negatives can be seen in cats infected within the last 1–3 months. • Do not use modified live vaccines. • Transmission is most commonly through cat-to-cat bites, grooming, shared dishes, litter boxes, in utero, or through nursing • Transmission is through direct contact and fomites. • Very resistant virus; disinfect with 1:32 dilution of bleach water • Readily inactivated by commonly used disinfectants for months to years • Cats should be tested for FIV and FeLV to rule out underlying immunodeficiency syndromes. Follow-Up 2 Notes 50 SECTION TWO: PREVENTATIVE CARE Lymphoma Fibrosarcoma Glomerulonephritis Toxoplasmosis Haemobartonellosis Chronic rhinosinusitis Persistent nasal discharge Herpetic ulcerative keratitis Permanent closure of nasolacrimal duct Table 2.15 / Feline Vaccination Protocol The site of vaccine injection varies between clinics, but it is important to have a designated location for each vaccine and to note these locations in each patient’s chart. Feline vaccines vary as to their route of administration: subcutaneously, intranasally/intraocularly, or transdermally. The Vet Jet transdermal vaccination system utilizes an internal spring system, which disperses the vaccine through the dermis into the dendritic cells. 2 Vaccine ≥16 Weeks of Age >16 Weeks of Age Injection Sitea Vaccine Classificationb FPV • Feline panleukopenia FCV • Feline calicivirus FHV-1 • Feline viral rhinotracheitis • 1 dose at 6–9 weeks, then repeat every 3– 4 weeks until 16 weeks (e.g., 1 dose at 8, 12, 16 weeks) • 1 dose 12 months after initial, then 1 dose every 1–3 years dependent on manufacturer and hospital policy • 2 doses, 3–4 weeks apart • 1 dose 12 months after initial, then 1 dose every 1–3 years dependent on manufacturer and hospital policy • SQ on right lower shoulder • IN/conjunctival sacs, depending on manufacturer Core FeLV • Feline leukemia • ELISA FeLV test for virus detection prior to vaccination • 1 dose at 8 weeks, then 1 dose 3–4 weeks later • Annually dependent on patient’s risk • Elisa FeLV test for virus detection prior to vaccination • 2 doses; 3–4 weeks apart • Annually dependent on patient’s risk • Transdermal on the left hind lower thigh area • SQ on the left lower thigh area Noncore Rabies • Rabies virus (RV) • 1 dose at 8–12 weeks dependent on vaccine type • 1 dose every 1–3 years dependent on vaccine type and state requirements • Annually using canary-pox vector rabies vaccine • 1 dose initially • 1 dose every 1–3 years dependent on vaccine type and state requirements • Annually using canary-pox vector rabies vaccine • SQ on right hind lower thigh area Core FIV • Feline immunodeficiency virus • 1 dose at 8 weeks, then 2 doses every 2–3 weeks • Annually dependent on patient’s risk • 3 doses every 2–3 weeks • Annually dependent on patient’s risk • SQ Noncore Core Core a Injection site, age of administration, and booster protocol may vary depending on the manufacturer of the vaccination. Recommendations by the individual manufacturer should be followed. The frequency may vary depending on the state’s requirements and the veterinarian’s protocol. Note: Possible reactions range from sensitivity at the injection site, a small bump or knot at the injection site, slight fever, hives, lethargy, to anaphylactic shock (vomiting, salivation, dyspnea, and incoordination) and injection site sarcomas. Any bump found at the injection site should be assessed by a veterinarian. b Core vaccines are those recommended to every dog. Noncore vaccines are recommended based on potential risk factors. ANIMAL CARE Along with medical care provided by the veterinarian, owners must take an active role in the day-to-day health of their animals. Dental care, grooming, and basic medical procedures can help provide the animal with increased health and longevity. Besides providing the basic care, it also allows the owners to be more aware of other health problems that might otherwise be missed (e.g., gum inflammation, tumors, pruritus, otitis externa). CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 51 Skill Box 2.9 / Client Education: Home Dental Care 2 Home dental care should be a daily part of each animal’s life. The commitment to time, energy, and resources from the owner will impact the quantity and quality of their animal’s life. • Brush the visible teeth (opposite side) and then repeat on the other side. Maintenance: Supplies: • Brush daily, at a minimum of 3 times a week. • Toothbrush (e.g., fingerbrush, pet toothbrush, human toothbrush), gauze, washcloth, pantyhose • Oral examination • Veterinary toothpaste, beef bouillon, garlic or tuna water Age: • Home dental care should begin at 8–12 weeks of age. Brushing is not critical until the adult teeth erupt, but starting early allows the animal to become accustomed to the procedure during an impressionable period of development. Introduction: • Regardless of age, introduce brushing slowly and gradually, allowing the animal to determine the amount of time at each stage. • As each step is begun, observe for the animal’s reaction and only advance to the next step once the animal is comfortable. • Massage the animal’s muzzle and lips gently. • Introduce your finger dipped in beef bouillon or garlic water (canine) or tuna water (feline) into the buccal pouch under the upper lip and rub the gum line. • Introduce your finger covered with a gauze, washcloth, or pantyhose and rub the gum line and teeth in a circular motion. • Introduce a pet toothbrush or a very soft human toothbrush held at a 45° angle to the tooth surface, brushing in a oval motion. • Introduce the toothbrush with veterinary toothpaste. • As the animal accepts the procedure, brushing of the lingual surfaces can begin. • Place the nonbrushing hand over the muzzle and tilt head backward to open the animal’s mouth. 52 SECTION TWO: PREVENTATIVE CARE • Gums: redness, swelling, bleeding, pus • Teeth: loss, instability, broken, change in color • Mouth: halitosis, growth Adjuncts to brushing: • Dental diets or treats • Rawhide bones (e.g., Nylabone) • Yearly dental examinations and cleanings, if needed Tips for successful brushing: • Select the same time each day to brush so the animal expects it (routine and repetition). • Brushing in the evening is often preferred as everyone is in a more quiet mood. • Sessions should be short, roughly 2–3 minutes. • Offer praise and reassurance during and following the brushing. Avoid: • Human toothpaste, baking soda, or hydrogen peroxide • Heavy restraint • Brushing aggressively • Brushing if the procedure may cause pain (e.g., recent thorough oral examination, existing CLL, exposed pulp cavities, gingivitis, ulcerations, tooth mobility) • Natural bones, cow hooves, hard nylon toys as they may fracture teeth Skill Box 2.10 / Grooming Skill Box 2.11 / Bathing Grooming is a segment of veterinary care that is limited and typically presents itself as client education. Even though staff may not routinely provide grooming services, clients often have questions regarding the general care of their pets. Brushing, bathing, and toenail trims are the most basic of grooming procedures. There are also certain procedures that may be performed during periods of medical conditions that must be continued routinely to avoid reoccurrence of the problem, such as anal gland expression and ear cleaning and flushing. Brushing should be a routine part of pet care to remove dead fur and dirt and to prevent matting. Besides providing the animal with a shinier and healthier coat and a chance to look and feel for abnormalities, it also allows bonding between the animal and the owner. There are many types of brushes and combs available for specific types of coats; a variety of options can be helpful. Applying a detangler spray before beginning may help with tangled or slightly matted fur. Using a systematic approach, begin at the head and work toward the tail. Use a gentle stroke, as ripping or pulling at the fur is painful and will make brushing a negative experience. For animals with long, thick coats, brush the fur against the natural lay of the fur and then finish with brushing fur down. Following up with a comb may help remove the extra loose fur. 1. Location: a safe place for both owner and animal to stand, a mixture of hot and cold water available, and an area able to withstand water (e.g., shaking wet dog) • Place a towel or mat in the bottom of the tub to supply traction for the animal. • Have a leash hook fastened to the wall so the animal can be secured without having to always have a hand on the animal. 2. Supplies: multiple towels, appropriate shampoo, plastic apron, gloves (depending on type of shampoo) and protective eyewear. 3. Comb, brush, and demat to remove excess fur, which allows better penetration of shampoo as detailed above. 4. Wet down the animal completely, making sure to get water down to the skin. 5. Apply the shampoo and lather the entire animal, including face. 6. Leave shampoo on for the amount of time indicated on the bottle or by the veterinarian. • Use a timer to ensure that the shampoo is on for the correct time: do not guess. 7. Rinse the animal completely, making sure to remove all soapy residue. 8. Dry the animal’s haircoat and ear canals with a combination of shaking (removes 95% of the water) and towels. • Blow in the animal’s ear to get them to shake. • Dry the ear canals, using either cotton balls or a vinegar rinse. Note: Keep the animal in a warm place until completely dry to avoid the animal becoming chilled. 9. Comb and brush out the animal after the bath to remove all the hair that was loosened. Note: Do not use lubricants in the eyes; it may trap the shampoo in the eye instead of protecting the eye. • Do not place an animal in a heater/dryer cage without direct supervision and access to water to prevent overheating and death of the animal. • If drying an animal with a blow dryer, be sure to keep the dryer on the lowest setting and continuously moving to prevent burns to the animals. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 53 2 2 Skill Box 2.12 / Nail Trimming Skill Box 2.13 / Anal Sac Expression Nail trimming is another routine part of pet care. Failing to trim the nails may lead to the nails growing into the pad of the paw, difficulty or inability of the pet to walk, and pain and pad injuries. Most animals are adverse to nail trimming and may need some coaxing. Choosing a time when the pet is tired and comfortable may make the experience more tolerable. When trimming, it is best to hold the trimmer perpendicular (cutting top to bottom) to the nail; when held parallel (cutting side to side), crushing and splintering of the nail may take place. When trimming nails, it is important to avoid cutting the quick, which consists of the blood vessels and nerves that supply the toenail. In dogs, light-colored nails are easy to trim as the blood supply is easily seen and avoided. Dark-colored nails can be difficult to trim and should be done in small cuts. As small cuts are made, the white to pink crescent shape will begin to appear in the middle of the nail. This represents the quick, and continuing to cut will eventually lead to bleeding. Remember to cut all nails including the dewclaws on both front and rear feet. The rear feet nails are typically shorter and require less trimming. In cats, the paw is gently squeezed to expose the nails and then they are trimmed to within 2 mm of the quick. 1. Supplies: gloves, lubricant (e.g., K-Y Jelly), alcohol, absorbent material (e.g., rolled cotton, paper towels, baby wipes), and deodorizer 54 SECTION TWO: PREVENTATIVE CARE 2. Put alcohol-soaked absorbent material into the gloved hand during the expression to catch the expressed material, insert the forefinger into the rectum, and immobilize the sac between the forefinger and the thumb on the outside of the rectum. 3. Gently apply pressure to the sac with thumb and forefinger (located at the 4 and 8 o’clock positions when looking at the anus), milking from the bottom of the sac upward toward the duct opening. 4. Note the amount and character of the material expressed. Normal secretions are a clear to slightly greenish, foul-smelling (similar to dead fish) substance that is a liquid to a paste in consistency. Material that is very thick or purulent or very dark should be brought to the attention of the veterinarian. 5. Clean the perianal area of the animal with alcohol-soaked material or baby wipe and then spray with a deodorizer. • If using powdered gloves, put 2 gloves on the hand doing the expression, then remove 1 glove after each sac is expressed. • If having difficulty expressing a gland, try rolling the skin outward with the finger outside the rectum to better expose the duct. • If having trouble with positioning, switch and use the thumb on the inside and the forefinger on the outside or teach yourself to be ambidextrous and express the right gland with the left hand and vice versa. Skill Box 2.14 / Ear Cleaning and Flushing Method Ear Cleaning Ear Flushing Equipment • Cotton ball • Cleaning solution (chlorhexidine, povidone iodine, Oti-clens, Epi-Otic) • Bulb syringe/syringe without the needle • towel • • • • • • Cotton ball Cleaning solution (Ceremune) Ear irrigator (filled with warm water) Video scope or endoscope Anesthetized patient 5 Fr red rubber feeding tube (cut to about ½ its length) Technique • Verify the patient has an intact tympanic membrane. • Using either a bulb syringe or syringe without the needle, fill the ear canal with cleaning solution. Be careful not to form a seal between the instrument and the ear canal, and do not use a direct stream on the tympanic membrane. • Put a towel or piece of roll cotton at the entrance of the ear canal and begin gently massaging the ear canal from the bottom up. This will work the solution from the bottom of the ear canal to the opening. With a cotton ball, gently wipe out any debris. Do not push cotton ball in the ear any farther than your finger will go easily. • Repeat steps 1 and 2 until the ear canal and solution on the cotton ball come out clean (5–10 times). • To dry the ear canal, use either a flushing solution or suction via an infant feeding tube attached to a syringe. • • • • • Take a picture of the ear canal. If cytology has not been done, take a sample of the ear debris. Insert the Ceremune or other ear cleaner, and massage gently for 3–4 minutes. Wipe out any excess at the entry of the ear. Insert the feeding tube onto the ear irrigator nozzle and turn on the machine, verifying that the pressure gauges are registering as prescribed in the manual. Position the video scope or endoscope into the ear, and then insert the feeding tube into the port and watch on the monitor screen to see the tip protrude from the scope. Depress the water button on the trumpet, release, and then depress the suction button and suction out debris and liquid. Repeat several times. Remove the feeding tube if debris is clogging the tip and clean. A reapplication of the ear cleaning solution may be necessary in ears with a lot of debris. Be sure to remove all of the Ceremune. Take a second picture of the clean canal. Insert any medications if needed. • • • • • • 2 Note: See Figure 1.19, Ear, page 13. CHAPTER 2 / PREVENTATIVE CARE AND VACCINATIONS 55 Chapter 3 3 Nutrition General Nutrition 58 Daily Caloric Requirement Worksheet for a Healthy Animal 59 General Life Stage Feeding Guidelines Body Condition Scoring System 62 Disease Nutritional Requirements 64 Obesity Management 68 60 Key Words and Termsa Aerophagia Alkali Amino acid Antigenic Bioactive amines Bioavailability Cachexia Carbohydrate Daily energy requirement Digestibility Energy Fat Fatty acid Fiber Hydrolyzed protein Kilocalorie a Life stage Malnutrition Meat byproducts Meat meal Metabolism Micronutrient Mineral Neonate Nitrogenous waste Nutrient Obesity Protein Resting energy requirement Vasoactive amines Vitamin Abbreviations Additional References, page AAFCO, Association of American Feed Control Officials BCS, body condition score BW, body weight CHF, chronic heart failure DER, daily energy requirement EPI, exocrine pancreatic insufficiency FLUTD, feline lower urinary tract disease GIT, gastrointestinal tract kcal, kilocalorie ME, metabolizable energy NPO, nothing by mouth PLE, protein losing enteropathy RBC, red blood cell RER, resting energy requirement Laboratory, 71 Parenteral nutrition, 422 Pharmacology, 567 Physical examination, 18 Urinalysis, 147 Key words and terms are defined in the glossary on page 631. 57 GENERAL NUTRITION 3 Proper nutrition is as important as physical examinations, vaccinations, and dental care in maintaining a healthy pet. Unfortunately, not much time is usually given to the subject during client education. Obesity remains the biggest nutritional challenge; it is estimated that 24–44% of dogs and cats in the United States are overweight. Understanding how to feed a pet according to its life stage, how to determine their current condition, how to alter their nutrition based on disease changes, and how to get a pet back to its ideal condition are the keys to proper clinical nutrition. The most important component of proper nutrition begins with a high-quality diet formulated to the appropriate life stage of the animal. Poor-quality, unbalanced, commercial diets; homemade diets of single-food items; indiscriminate mixtures of singlefood items; and variable supplements will lead to dietary imbalances. Along with proper nutrition, fresh, clean water must be provided at all times. Owners often look to the veterinary staff for a better understanding of the “right” diet to feed their pet. Many would like a concrete comparison 58 SECTION TWO: PREVENTATIVE CARE between different foods, but unfortunately this is virtually impossible to do. The information provided in the ingredient list and on the information panel appears at first glance to be consistent between products, but the variables that exist render a comparison unattainable. The most reliable way to evaluate a food is to evaluate the health and appearance of the animal that is eating it. Each animal is an individual and will handle each diet differently. Some basic guidelines to providing a quality diet include feeding diets that have passed the Association of American Feed Control Officials (AAFCO) feeding trials, feeding diets appropriate for the animal’s life stage, and feeding diets containing meat (not including meat byproducts and meat meal). Some indications that a diet change may be indicated for a particular pet are poor body condition, flatulence, borborygmus, ↑ fecal volume and frequency, changes in the expected appearance of the haircoat. Home-prepared diets can be a very valuable option when an approved recipe is followed to guarantee the proper nutrients have been included. Only those recipes formulated by a credentialed veterinary nutritionist should be considered and then not altered. Skill Box 3.1 / Daily Caloric Requirement Worksheet for a Healthy Animal Many factors affect the energy requirements of animals. Understanding these factors may prevent an animal from becoming obese. Daily caloric requirements are altered by the physiologic state (e.g., adult maintenance, pregnancy, lactation, and growth), activity level, temperament, environmental temperature, and the diet’s digestibility. The calculations below provide a starting point; adjustments will need to be made based on each individual animal. Step 1: Calculate Daily Resting Energy Requirement (RER) RER = 70 × (current body weight in kg)0.75 or, for animals weighing between 2 and 30 kg: RER = (30 × current body weight in kg) + 70 = ______ kcal/day Adjust kcal based on visual and manual examination and the BCS of animal. Tip: To calculate (BW kg)0.75 without a scientific calculator: multiply the weight by itself 3 times, then take the square root twice Step 2: Calculate daily energy requirement (DER) by multiplying the RER by the activity factor. Life Stage Activity Factor (RER × ______ = DER) Canine Feline 2.0 1.6–2.0 Gestation Weeks 5–9 Lactation Week 1–2 1.5a Week 3–5 a 2.0 1.5 1.5–5.0 Growth Weaning to 50% of adult BW 3.0 3.0 51% of adult BW to adult 2.0 2.0 Inactive, neutered 1.6 1.2 Inactive, intact 1.8 1.4 Active/working 2.0–6.0 1.6 Adult a 25% of the RER should be provided for each pup in addition to the dam’s DER. These calculations do not take into consideration the type of breed and their differences in growth requirements. Adjust kcal based on visual and manual examination of animal. Step 3: Calculate volume of food required ______ kcal/day/ ______ kcal/cup or can of food = ______ cup/can(s) of food/day Step 4: Calculate amount of each feeding ______ cup/can(s) of food/day/2–3 feedings per day = ______ cup/can(s) of food/feeding CHAPTER 3 / NUTRITION 59 3 Table 3.1 / General Life Stage Feeding Guidelines Each stage of an animal’s life presents changes in nutritional needs. The overall goal of nutrition is to obtain an optimum body condition score (see Table 3.2 Body Condition Scoring System, page 61) while providing the correct balance of nutrients, vitamins, and minerals. Age Diet Feeding Method Comments Birth to Weaning • Dam/queen’s milk • Commercial replacement diets • Home prepared replacement diets • See Skill Box 2.1 Care and Feeding of Orphaned Puppies and Kittens, page 27. • Energy requirement is 22–26 kcal/100 g • Begin introducing puppy or kitten diet at 3–4 weeks of age as milk will no longer provide adequate calories or nutrients • Weaning begins at 6–8 weeks of age • Nursing neonates will feed ad lib • See Skill Box 2.1 Care and Feeding of Orphaned Puppies and Kittens, page 27. • Starting solid food • Mix growth food with warm water to moisten and make into a slurry; place food in a shallow dish. • Allow free access 3–4 times a day. • Remove after 20–30 minutes to prevent bacterial overgrowth. • Neonates can be encouraged to eat by placing their feet in the food, smearing food on their lips, or introducing food into their mouths. • Weaning • Complete weaning should not start before 6 weeks of age (preferably 7–8 weeks of age) and not until close human contact has occurred, and typically does not need assistance after solid foods have been started. • The dam/queen should be separated from the neonates the day before weaning. The neonates should be fed, and food should be withheld from the dam/queen. Water is not removed. • The neonates should be reunited with the dam/queen overnight and be allowed to nurse to drain the mammary glands. Food only should be withheld from both the dam/queen and the neonates overnight. • The neonates are removed from the dam/queen the next day • Body fat stores are only 1–2% at birth, presenting the risk of hypoglycemia, starvation, and hypothermia. • Adequate glycogen reserves do not develop until after first few days of nursing. • All neonates need to receive colostrum in the first 24 hours of life to ensure transfer of passive immunity. • Hypothermia can lead to poor nursing. Weaning to 12 Months • Puppy • Highly digestible, high-quality protein • 25–29% protein of ME • Large- and giant-breed dogs • Overfeeding and extra micronutrients (e.g., calcium) during rapid growth phase contribute to obesity and developmental orthopedic disease. • Maintain feeding puppy diet until an adult to avoid ↑ calcium consumption. • Adjust food intake to maintain a BCS of 2/5. • Kitten • 30% protein of ME • Maintain feeding kitten diet until maturity (10–12 months) if obesity is present, then ↓ amount of food fed. • Puppy • 2–4 measured feedings per day • Large- and giant-breed dogs • Measured feedings 3–4 meals daily • Remaining food after a meal should be discarded and subsequent meals should be reduced in quantity. • Kitten • Free-feed or measured feedings 2–3 times a day • Neutering ↓ energy requirements by 24–33% • Obesity: developmental orthopedic disease (large breed) • Thin: hypoglycemia (small breed) Puppy and Kittens 3 60 SECTION TWO: PREVENTATIVE CARE Adult Table 3.1 / General Life Stage Feeding Guidelines (Continued) Age Diet Feeding Method Comments Maintenance • High-quality adult food • Homemade diets made from approved published recipes • 2–3 measured feedings per day • See Skill Box 3.1 Daily Caloric requirement Worksheet, page 58. • Obesity: diabetes, osteoarthritis, skin problems, surgical risk • Thin: hypoglycemia, hypothermia, muscle disorders 3 Pregnancy Canine • Diet should gradually be changed during the last 3 weeks to a puppy growth diet to provide additional nutrients. • Avoid • Carbohydrate-free meat-type diets should be avoided during gestation and whelping to prevent hypoglycemia and ↑ neonate death. • During the first 5 weeks, the feeding schedule should not change, and the dam should maintain her normal weight. • Weeks 6–9 • Frequency • Feed smaller, more frequent meals to accommodate the shrinking stomach size • Amount • ↑ 15% each week • By gestation, the dam’s weight should ↑ 15–25%. • Obesity: ↓ ovulation, ↓ litter size, large neonates, dystocia • Thin: trouble conceiving, ↓ birth weights, ↑ neonate death Feline • High-quality diet intended for reproduction/lactation or growth • Weeks 2–9 • Amount • ↑ Gradually to a total ↑ of 25–50% • By gestation, the queen’s weight should ↑ by about 40%. • Obesity: large neonates, dystocia • Thin: trouble conceiving, abortion, ↓ birth weights, ↑ neonate death Lactation Canine • High-quality puppy growth food • Avoid • Low-calorie diets (e.g., weight-reducing diets) • Feed free-choice • Daily energy requirements are approximately 3 times that of nonlactating adults. • Lactation peaks at 3–5 weeks postpartum and is maintained until 8 weeks postpartum. • The dam requires approximately 25% of her DER additional for each neonate. • Obesity/thin: insufficient milk production Feline • High-quality diet intended for reproduction/lactation or growth • Lactation peaks at 3–4 weeks postpartum • The queen requires 2–3 times her DER during lactation. See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58. • Obesity/thin: insufficient milk production Geriatric • High-quality adult food for healthy animals • Homemade diets made from approved published recipes • Changes in diet (e.g., protein, fat, phosphorous, sodium, fiber, vitamins, minerals) can be made based upon medical conditions. • 2–3 measured feedings per day • See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58, on calculating the appropriate amount of food. • The caloric intake may need to be reduced to obtain the desired BCS. • Avoid placing feeding dishes in hard-to-reach places. • Obesity: diabetes, osteoarthritis, skin problems, surgical risk • Thin: hypoglycemia, hypothermia, muscle disorders CHAPTER 3 / NUTRITION 61 Table 3.2 / Body Condition Scoring System The Body Condition Scoring System standardizes the interpretation of the overall physical appearance of the animal. It should be a basic part of every examination and should be noted in the record for future comparison. This technique can be easily and quickly taught to clients as part of weight management at home. The BCS can change by 1 value with a 10% change in body weight. 3 Canine Body Condition Score 1: Very Thin Ribs: easily visible and felt with no cover Waist: severe waist Tail Base: lumbar vertebrae and pelvic bones are raised with no fat between the skin and bone Side View: severe abdominal tuck Overhead View: accentuated hourglass shape 2: Underweight Ribs: easily felt with minimal fat cover Waist: easily noted Tail Base: bones are raised with minimal fat between the skin and bone Side View: prominent abdominal tuck Overhead View: marked hourglass shape 3: Ideal Ribs: easily felt with slight fat cover Waist: observed behind ribs Tail Base: smooth contour but bones can be felt under a thin layer of fat Side View: abdominal tuck Overhead View: well-proportioned waist 62 SECTION TWO: PREVENTATIVE CARE Feline Table 3.2 / Body Condition Scoring System (Continued) Canine Body Condition Score Feline 4: Overweight Ribs: difficult to feel with moderate fat cover Waist: poorly discernible Tail Base: some thickening but bones can be felt under a moderate layer of fat Side View: no abdominal tuck Overhead View: back is slightly broadened 3 5: Obese Ribs: difficult to feel under thick fat cover Waist: absent Tail Base: thickened and difficult to feel bones beneath prominent layer of fat Side View: fat hangs from the abdomen Overhead View: markedly broadened and prominent paralumbar fat deposits CHAPTER 3 / NUTRITION 63 Table 3.3 / Disease Nutritional Requirements 3 Each disease or combination of diseases alters the nutritional requirements of a patient. Each patient should have a complete nutritional evaluation to ensure the type of diet and the feeding method are appropriate. The overall consideration regarding nutrition is to optimize BCS. Often it is more important to maintain a patient eating versus providing the exact nutritional requirements. For example, it is more important for a patient with CHF to consume enough food to prevent cachexia than it is to restrict sodium. It often requires a dedicated owner to cater to the changing desires of the patient along with providing the necessary nutritional requirements. It is beyond the scope of this book to provide specific alterations; please consult dedicated nutritional references and seek the advice of a credentialed veterinary nutritionist for specific nutritional alterations. Disease Objective Comments Anemia • Support RBC production. • Nutritional evaluation: minerals (e.g., iron), protein, vitamins (e.g., B) • Iron deficiency is usually due to excessive loss (e.g., hemorrhage, GIT ulcers, and ectoparasitism) versus inadequate intake. Bone Loss and Fracture Repair • Ensure diet is properly balanced. • Ensure adequate energy and protein intake. • Nutritional evaluation: energy, minerals (e.g., calcium, phosphorus), protein • Supplemental calcium must be absorbable and balanced with phosphorous intake. Cardiac Disease • • • • Control or correct cachexia. Maintain BCS. Control sodium retention. Encourage eating. • Nutritional evaluation: amino acids (e.g., taurine), carnitine, energy, minerals (e.g., chloride, magnesium, phosphorus, potassium, sodium), water • Sodium and chloride restriction is based on the degree of cardiac disease • Additional sources of sodium should be considered (e.g., softened water, treats, table scraps) when determining total sodium intake. Constipation • • • • Normalize GIT motility. ↑ Water consumption ↑ Bulk or ↓ quantity Optimize BCS. • • • • • • • • Nutritional evaluation: fiber, water Feed a highly digestible diet. ↑ Fiber ≤5% per week until clinical signs resolve Additional fiber may be achieved through therapeutic veterinary diets or adding ≤10% fiber to regular diet (e.g., pumpkin, high-fiber cereal). Provide small, frequent meals. ↑ Exercise and prevent obesity. Encourage defecation (e.g., frequent walks, clean litter box). Check anus/rectum for causes of poor defecation habits, tenesmus, or dyschezia. Degenerative Joint Disease • ↓ Degenerative joint changes • Optimize BCS. • Nutritional evaluation: fatty acids, vitamins (e.g., E) • ± Chondroprotectives Dental Disease • Prevent or correct periodontal disease. • Optimize oral health. • Nutritional evaluation: carbohydrates, minerals (e.g., calcium, phosphorus), protein, vitamins (e.g., A, B, C, D), water • Food texture and composition may contribute to ↓ plaque accumulation. Diabetes Mellitus • Optimize BCS. • Minimize postprandial fluctuations in blood glucose. • Consistent feeding times and caloric intake • Nutritional evaluation: energy, fat, fatty acids, fiber, minerals, protein, soluble carbohydrates, water • Avoid semimoist foods as they contain simple carbohydrates and may have a hyperglycemic effect. • Provide small, frequent meals and weigh animal frequently. • Changes in exercise and weight may necessitate altering the insulin dose. 64 SECTION TWO: PREVENTATIVE CARE Table 3.3 / Disease Nutritional Requirements (Continued) Disease Objective Comments Exocrine Pancreatic Insufficiency (EPI) • Correct malnutrition. • Reduce requirements for digestive enzymes. • ↑ Caloric intake/density • Optimize BCS. • Nutritional evaluation: fat, fiber, vitamins (e.g., A, D, K, cobalamin, folate) • Avoid high-fiber diets. • Provide small, frequent meals. Flatulence • ↓ Intestinal gas production and bacterial fermentation of undigested food • ↓ Aerophagia • • • • Food Allergy • Identification and avoidance of offending foods (protein) and/or food additives • Relieve clinical signs (e.g., otitis, pruritus, dermatitis, erythema, peripheral lymphadenopathy). • Nutritional evaluation: food additives, protein, vasoactive or biogenic amines • An elimination diet is feed exclusively for 8–12 weeks consisting of 1–2 protein sources the patient has not be exposed to and void of food additives, vasoactive and biogenic amines, and excess protein. • Regardless of diet fed (e.g., commercial or home prepared), it must be nutritionally adequate for the patient’s life stage and condition. • Diet should be continued 2–3 weeks past glucocorticoid administration. • Canned food contains the least amount of additives. • Feeding dishes should be glass, ceramic, or stainless steel. • Outdoor pets should be confined to avoid dietary indiscretions. • Avoid all flavored medications, treats, table scraps, and vitamin supplements. • With the disappearance of clinical signs, begin feeding 1 eliminated food item back daily for 7 days, discontinue if relapse is noted or assume no allergy if no reactions are seen after 7 days. Hepatic Disease • Maintain body weight and BCS. • Promote hepatic regeneration. • ↑ Caloric intake/density • Nutritional evaluation: amino acids (e.g., taurine), energy, fat, fiber, minerals (e.g., iron, potassium, zinc), protein, vitamins (e.g., C, E, K) • Feed a highly digestible diet. • Provide small, frequent meals while slowly ↑ amount fed over a few days. Hepatic Lipidosis • Correct anorexia and malnutrition. • ↑ Caloric intake/density • Nutritional evaluation: carnitine, energy, fat, minerals (e.g., iron, potassium, zinc), protein, vitamins (e.g., C, E, K) • Recovery is directly related to early diagnosis and treatment via enteral or parenteral nutrition. Hyperadrenocorticism • Prevent or correct cachexia. • Optimize BCS. • Nutritional evaluation: fat, fiber, minerals (e.g., chloride, sodium), protein, water • Feed a highly digestible diet. Hyperthyroidism • Correct cachexia. • Optimize BCS. • Nutritional evaluation: energy, fat, minerals (e.g., calcium, chloride, iodine, iron, phosphorus, potassium, selenium, sodium), protein, water • Feed a highly digestible diet. • Poor absorption of many nutrients and ↑ metabolism Hypoadrenocorticism • Optimize BCS. • Nutritional factors to evaluate: energy, minerals (e.g., chloride, potassium, sodium), protein, water • Feed a highly digestible diet. 3 Nutritional evaluation: carbohydrate, fiber, protein, variable per patient Feed a highly digestible diet. Provide small, frequent meals. Discourage gluttony; provide a noncompetitive environment or slow consumption via novel methods. • ↑ Exercise and ↓ stress CHAPTER 3 / NUTRITION 65 Table 3.3 / Disease Nutritional Requirements (Continued) Disease Objective Comments Hypothyroidism • Optimize BCS. • Nutritional evaluation: fat, energy, fiber, trace minerals Inflammatory Bowel Disease • ↓ Antigenic stimulation of the GIT • Provide GIT rest and normalize motility. • ↑ Water consumption • Nutritional evaluation: energy, fat, fatty acids, fiber, minerals (e.g., potassium, zinc), protein, vitamins (e.g., thiamin, vitamin K) • Diets may consist of a highly digestible low-residue GIT diet, ↑ fiber, or an elimination diet (a “sacrificial” novel protein is fed initially while the GIT is healing and then replaced by a second novel protein or hydrolyzed protein diet long term). Obesity • ↓ Body weight and optimize BCS • Control caloric intake. • Prevent obesity-related diseases. • Nutritional evaluation: carbohydrates, energy, fat, fiber, protein • Prevention is easier than treatment of obesity. • See Skill Box 3.2 Obesity Management, page 67. Oncology • Prevent or correct cancer cachexia. • ↑ Nutrient intake • Encourage eating. • Nutritional evaluation: amino acids (e.g., arginine, glutamine, glycine, tyrosine, phenylalanine, methionine, asparagine), fat, fatty acids, carbohydrates, protein, vitamins (e.g., retinoids, vitamins C and E, beta-carotene) • Feed a highly digestible diet. • Nutritional intervention must begin early in disease to prevent cachexia. Orthopedic Disease, Developmental • ↓ Nutrition-related disease • Optimize BCS. • Nutritional evaluation: energy, fat, minerals (e.g., calcium, copper, phosphorus, zinc), vitamins (e.g., A, C, D) • Overfeeding and extra vitamins (e.g., calcium) during rapid growth phase in large- and giant-breed dogs lead to skeletal disease. • Switching growing animals to an adult food should be avoided as nutritional factors may be inappropriately altered (e.g., calcium). • See Table 3.1 General Life Stage Feeding Guidelines, page 58. Pancreatitis • ↓ Pancreatic secretions • Provide pancreatic rest. • Optimize BCS. • • • • • Nutritional evaluation: fat, protein, water Feed a highly digestible diet. Enteral and/or parenteral feeding may be part of the initial treatment. Traditional low-fat, weight-reducing diets may be too calorie restrictive. Canine: NPO for 3–7 days, begin with small amounts of water, gradually add in a carbohydrate (e.g., rice) and then a protein source of ↑ bioavailability (e.g., cottage cheese, lean meat) Protein Losing Enteropathy (PLE) • Correct cachexia. • ↓ Enteric loss of plasma protein • • • • • Nutritional evaluation: carbohydrates, fat, fiber, protein Feed a highly digestible diet. Determining the underlying cause of PLE may alter nutrition. Monitor for protein malnutrition. Provide small, frequent meals. Renal Disease • Delay progression of renal failure. • ↓ Amount of nitrogenous waste (↓ azotemia) • Prevent malnutrition and optimize BCS. • ↑ Water consumption • Encourage eating. • Nutritional evaluation: acid load, amino acids (e.g., arginine), energy, fat, fiber, minerals (e.g., chloride, phosphorus, potassium, sodium, protein, vitamins (e.g., A, B, D), water • Feed a highly digestible diet. • Avoid excess dietary protein in moderate to severe renal failure. • Protein recommendations: • Dogs: 2.0–2.2 g/kg/day • Cats: 3.3–3.5 g/kg/day • Monitor and control mineral imbalances (e.g., phosphorus, calcium). • Optimizing BCS is more important than restricting protein. • Sodium restriction should take place gradually over 2–4 weeks. 3 66 SECTION TWO: PREVENTATIVE CARE Table 3.3 / Disease Nutritional Requirements (Continued) Disease Objective Comments Urolithiasis, Canine– Ammonium Urate • Maintain alkaline urine (pH of 7.0–7.5). • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: protein, water • Dissolution on average take 4 weeks. • Meat-based diets tend to have ↑ purine; vegetable-based diets may be more suitable. Calcium Oxalate • Maintain alkaline urine (pH of 7.1–7.7). • Prevent uroliths. • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: minerals (e.g., calcium, magnesium, sodium), oxalates, protein, vitamins (e.g., B6, C, D), water • Medical regimen dissolution is not possible for calcium oxalate stones, once formed. Cystine • Maintain alkaline urine (pH of 7.5). • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: protein, water • Dissolution can be possible with the addition of 2-MPG. Struvite • Maintain acidic urine (pH of 6.2–6.4). • Resolve underlying infection. • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: minerals (e.g., magnesium, phosphorus), protein, water • Dissolution on average takes 3.5 months. • Avoid long-term feeding of dissolution diet due to ↓ protein and sodium. • Maintain alkaline urine (pH of 6.6–6.8). • Prevent uroliths. • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: fat, fiber, minerals (e.g., calcium, magnesium, sodium), oxalates, protein, vitamins (e.g., B6, C, D), water • Medical regimen dissolution is not possible for calcium oxalate stones, once formed. • Maintain acidic urine (pH of <6.4) • Dissolution and prevention of uroliths • ↑ Water consumption and subsequent ↓ urine concentration • Nutritional evaluation: fat, minerals (e.g., magnesium, phosphorus, potassium), protein, water • Average dissolution is 35 days after negative radiographs • Avoid feeding dissolution diet to immature, pregnant/lactating, renal failure, CHF, metabolic acidosis, hypertensive or hypokalemic patients • Free choice feeding provides a more desirable stable urinary pH, but may contribute to obesity • Provide GIT rest to ↑ gastric secretions and normalize motility. • ↑ Water consumption • ↑ Bulk • ↑ Caloric intake/density • Nutritional evaluation: amino acids (e.g., glutamine), energy, fat, fiber, minerals (e.g., chloride, potassium, sodium), water • NPO for 24–48 hours, offer small amounts of water every 2–3 hours, then begin small amounts of food 6–8 times a day • Gradually reintroduce normal diet after diarrhea is resolved (2–3 normal stools in a row). • Small, frequent meals to prevent gluttony Urolithiasis, Feline Calcium Oxalate Struvite Vomiting/Diarrhea 3 CHAPTER 3 / NUTRITION 67 Skill Box 3.2 / Obesity Management 3 As the rate of obesity among companion animals continues to rise, clients are in the need of obesity management education. Obesity alone can lead to or further contribute to numerous health concerns, such as diabetes, FLUTD, hepatic lipidosis, orthopedic diseases, and skin diseases. Although prevention early on is the key, a weight loss program can be successfully implemented and carried out with appropriate owner compliance. Becoming overweight is as simple as consuming more energy than the body is able to utilize. There are some medical conditions that can contribute to obesity (e.g., hypothyroidism), but the majority of animals are simply eating too much relative to their exercise/activity level. Therefore, decreasing the amount of food consumed or increasing the amount of exercise will lead to weight loss. Obesity management should be implemented when an animal is classified as having a body conditioning score of 4/5 or 5/5. See Table 3.2 Body Condition Scoring System, page 61. The following steps along with owner compliance should provide a happier and healthier pet. Additional information for the owner should include monitoring the amount of treats, the feeding habits of other family members, and the foods of other household pets. • A full examination of the patient along with appropriate diagnostic testing submitted to rule out medical issues (e.g., blood work, urinalysis) • Obtain a complete dietary history including the names and amounts of food fed (e.g., commercial diets, home prepared diets, treats, table scraps), access to additional food sources (e.g., other pet’s food, other family members or neighbors feeding the pet, hunting) • Calculate the current caloric intake and restrict to 60–80% of this amount. If it is not possible to obtain an accurate diet history, calculate the DER for the optimal weight of the patient. See Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58. 68 SECTION TWO: PREVENTATIVE CARE • Verify the protein content of the food at the recommended calories is adequate for that particular animal (1 g protein/lb body weight/day). Failure to verify protein content may lead to muscle loss along with fat loss. • Set smaller, more reasonable weight loss goals over a specified amount of time. The use of the BCS can help the owner better understand the goal. • Weigh the animal every 2–3 weeks to ensure a weight loss and verify all recommendations are being followed. The goal of weight loss is 1–2% per week; if this number is not obtained, further restrictions in calories should be done. Weight loss >2% a week is thought to be detrimental to the patient’s health. • Treats should be <10% of the total daily calories and must be calculated into the total daily calories. • Start or increase the daily exercise program to ↑ calorie expenditure, ↑ muscle mass, and stimulate metabolism. • The addition of microsomal triglyceride transfer protein inhibitors (e.g., Slentrol) may prove beneficial, as well as modifying feeding amounts and habits. Tips for success: • Feed multiple small meals a day to satisfy the pet. • Provide appropriate snacks (e.g., low- calorie commercial treats, plain popcorn, plain rice cakes). • Enlist all family members to be active participants in the weight loss program. • Keeping pets out of the kitchen during preparation and consumption reduces begging and owner’s impulse to feed. Section Three Diagnostic Skills Chapter 4: Laboratory 71 Chapter 5: Imaging 157 Color Plate Chapter 6: General Medicine 201 Chapter 7: Emergency Medicine 299 Chapter 4 4 Laboratory Blood Chemistries 74 Blood Collection, Handling, Storage, and Transport Tips 74 Blood Collection Tubes 75 Blood Chemistries 76 Bone Marrow Evaluation 83 Bone Marrow Collection, Handling, Storage, and Transport Tips 83 Supplies for Bone Marrow Collection 84 Smear Techniques 84 Evaluation 85 Bone Marrow Evaluation 85 Cell Type Identification 86 Interpretation 88 Cytology 88 Cytology Collection, Handling, Storage, and Transport Tips 88 Collection Techniques 88 FNB Needle and Syringe Selection 89 Smear Techniques 90 Evaluation 91 Cytologic Criteria of Malignancy 92 Figure 4.4: Cytologic Criteria of Malignancy Specific Tumor Cells 94 Interpretation 95 Fecal Cytology 96 Vaginal Cytology 97 Classifying Vaginal Cells 97 Staging the Estrus Cycle 98 Function Tests 98 Hematology 104 Complete Blood Count 105 Hemacytometer Use 108 Calculating a Differential 108 Evaluation 108 RBC Alterations and Morphology 108 WBC Morphology 112 WBC Alterations 113 WBC Left Shift 114 Platelet Morphology 115 Platelet Alterations 115 Coagulation Tests 115 Coagulation Screening 115 Coagulation Tests 116 93 71 Blood Transfusions 119 Crossmatching 119 Blood Typing 120 Immunology and Serology Tests 120 Microbiology 122 Microbiology Collection, Handling, Storage, and Transport Tips 122 4 Collection Techniques 123 Specimen Storage 124 Most Commonly Used Culture Media 125 Culture Media Inoculation and Incubation 126 Evaluation of Culture Growth 127 Staining Solutions and Procedures 127 Staining Problems 130 Bacteria Identification 130 Fungi Identification 133 Parasitology 134 Fecal Collection, Handling, Storage, and Transport Tips 134 Endoparasite Examination Methods 134 72 SECTION THREE: DIAGNOSTIC SKILLS Fecal Flotation Solutions 137 Blood Parasite Examination Methods Ectoparasite Examination Methods 138 139 Figure 4.35: Relative Size of Parasite Eggs Endoparasites 139 Ectoparasites Urinalysis 139 145 147 Urine Collection, Handling, Storage, and Transport Tips 147 Urine Examination/Urinalysis Gross Examination Preparation 147 148 149 Chemistry Strip Examination 149 Sediment Examination 150 Reporting of Bacteria and Sperm 151 Sediment Examination Urine Artifacts 155 151 Key Words and Phrasesa Agglutination Aggregation Anisocytosis Anisokaryosis Anticoagulants Axonemes Axostyle Basophilic Brownian movement Carbohydrate Cellularity Cestode Colorimetric Cornified Crenation Dermatophyte Encephalopathy Enzyme Epithelial Extracellular Extrinsic Fibrinogen Genal combs Globulin, α Globulin, β Globulin, γ Gluconeogenesis Glycoaminoglycans Glycogenolysis Granularity Hemolyzed Hemostasis Heparinized Hepatoid Hydatid cyst Hypercellular Hyperplasia Hyperthenuric Hypocellular Hypochromic Hypoplasia Hypothenuric Inanimate Intermediate host Intracellular Intrinsic Lipemic a Abbreviations Lyophilized Lysed Lysosomes Macrocytosis Macrokaryosis Mesenchymal Metabolism Microfilariae Mitotic figures Mordant Mucoprotein Nematode Normocellular Normochromic Nucleoli Oncosphere Oncotic Oocyst Operculum Paratenic host Percutaneous Plasma Pleomorphism Poikilocytosis Polychromatophilic Polycythemia Postprandial Prepatent period Preprandial Proglottid Pronotal Protozoa Pyknotic Rickettsiae Rodenticide Roulleaux Serum Sporangium Sporulated Thrombosis Trematode Trophozoite Urolithiasis Vacuoles μg, microgram μm, micrometer μmol, micromole AchRs, serum antibody against nicotinic ACT, activated clotting time ACTH, adrenocorticotropic hormone ADH, antidiuretic hormone AIHA, autoimmune hemolytic anemia Alk phos, alkaline phosphatase ALP, alkaline phosphatase ALT, alanine aminotransferase APTT, activate partial thromboplastin time AST, aspartate aminotransferase AT, adrenocortical tumors BA, blood agar BMBT, buccal mucosal bleeding time BTT, light blue top tube BUN, blood urea nitrogen CBC, complete blood count CDV, canine distemper virus Cl, chloride CNS, central nervous system CO2, carbon dioxide cPLI, canine pancreatic lipase immunoreactivity DEA, dog erythrocyte antigen DIC, disseminated intravascular coagulation dL, deciliter DM, diabetes mellitus EDTA, ethylenediaminetetra-acetic acid F, Fahrenheit FDP, fibrin degradation product FeLV, feline leukemia virus FIP, feline infectious peritonitis FIV, feline immunodeficiency virus fL, femtoliter FNA, fine needle aspirate FNB, fine needle biopsy FSP, fibrin split product GIT, gastrointestinal tract GRNTT, green top tube GTT, gray top tube HAC, hyperadrenocorticism HCO3, bicarbonate Hct, hematocrit IFA, immunofluorescence Additional Resources, page IgE, immunoglobulin gamma E IM, intramuscular IMHA, immune-mediated hemolytic anemia IV, intravenous K, potassium kg, kilogram KPO4, potassium phosphate L, liter LTT, lavender top tube MC, MacConkey agar MCHC, mean corpuscular hemoglobin concentration MCV, mean corpuscular volume mEq, milliequivalent mg, milligram Na, sodium ng, nanogram NMB, new methylene blue NSAIDs, nonsteroidal anti-inflammatory drugs PAP, immunoperoxidase test PCR, polymerase chain reaction PCV, packed cell volume PDH, pituitary-dependent hyperadrenocorticism pg, picogram pH, potential of hydrogen PIVKA, protein induced by vitamin K antagonism pmol, picomole PT, prothrombin time PTH, prothrombin time RBC, red blood cell RTT, red top tube SAP, alkaline phosphatase SGOT, serum glutamic-oxaloacetic transaminase SGPT, serum glutamic pyruvic transaminase SST, serum separator tube T3, triiodothyronine T4, tetraiodothyronine TBT, toenail bleeding time TLI, trypsin-like immunoreactivity TP, total protein TRH, thyroid releasing hormone TSH, thyroid stimulating hormone TT, thrombin time TWBC, total white blood cell count U, unit USG, urine specific gravity WBC, white blood cell Anesthesia, 439 Canine Transmissible Diseases, 38 Disinfectants, 627 Feline Transmissible Diseases, 44 General Medicine, 201 Injections, 348 Oncology, 273 Pharmacology, 567 4 Key words and terms are defined in the glossary on page 631. CHAPTER 4 / LABORATORY 73 P 4 roficiency in laboratory skills is one of the most important skills of a veterinary hospital. Each clinic will use their laboratory to different levels, but the proper technique and understanding of each procedure should always be maintained for the most accurate results. The key to learning laboratory skills is to be able to recognize the normal. Having a clear understanding of what is normal allows a person to more quickly identify the abnormal. This chapter covers all aspects to laboratory medicine. Each section begins with the proper way to collect, handle, store and transport laboratory samples, followed by the precise steps needed to perform each task. Variation may exist among some protocols depending on a particular laboratory. Laboratory medicine is a critical part of each diagnosis, and this process often begins with the technician. BLOOD CHEMISTRIES Blood chemistries evaluate the various blood levels to reach an insight into the different bodily functions. The critical part of blood chemistries is the collection and handling of each sample. For example, allowing a blood sample to remain at room temperature may elevate some chemistries and decrease others, leading to a possible incorrect diagnosis, treatment, and outcome. Extreme care and diligence should be taken with each sample to ensure the most accurate results. Blood Collection, Handling, Storage, and Transport Tips Collection • Blood samples should be collected from a fasted patient, at least 2 hours postprandial, preferably 4–6 hours. Lipemic samples may lead to hemolysis and therefore ↓ RBC counts. Lipemic and hemolyzed samples can also falsely alter measured serum chemistries. • When feasible, enough blood should be collected to run the tests 3 times; this allows for human error, machine error, and dilution if needed. • Venipuncture site and technique significantly contribute to the quality of the sample. • Always remove the needle to the syringe and the stopper of the tube to let the blood run down the inside of the tube. Sticking a needle 74 SECTION THREE: DIAGNOSTIC SKILLS through the rubber stopper contributes to further hemolysis, especially with a <25-gauge needle. Ideally, a vacutainer system should be used to ↓ hemolysis and ensure the correct blood/anticoagulant ratio. Handling • Fill the anticoagulant tubes first to minimize clot formation, ending with the plain tubes. • Gently mix any tube containing an interactive ingredient, to avoid hemolysis. • Blood smears should be made immediately, using fresh blood after blood collection and fanned to facilitate quick drying. (See Skill Box 4.5, Smear Techniques, page 84.) • Blood smears made with an excessive amount of blood will force the feathered edge off the end of the slide, therefore pushing the larger cells off. • Allow blood to clot in an upright position to prevent cells from sticking to the rubber stopper and hemolyzing during centrifuging. • Remove serum from contact with the cells within 30–45 minutes, to prevent altered laboratory results. • Each tube should be clearly labeled with the patient’s full name, date, and time of collection. Storage • If a sample will not be evaluated in 4–6 hours, the plasma or serum should be poured off and refrigerated. • Blood smears should be dried completely to avoid the formation of condensation inside the slide container and subsequent damage of cellular morphology. • Blood smears should be made and stored at room temperature; refrigeration may cause condensation therefore damaging the cellular morphology. • Do not freeze whole blood, because this causes hemolysis. • Samples to be frozen should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. Transport • Wrap ice packs or blood tubes with paper towels or newspapers to avoid direct contact and subsequent hemolysis. Table 4.1 / Blood Collection Tubes Tube Contents Uses General Information • Glucose determinations • Prevents RBCs from metabolizing glucose by inhibiting enzymes in the glycolytic pathway to more accurately measure blood glucose concentrations than an SST or RTT (e.g., diabetes mellitus and insulinoma) Whole Blood (unclotted) or Plasma Samples • Immediately invert tubes 6–10 times to prevent coagulation. Gray top tube (GTT) • Potassium oxalate and Sodium fluoride 4 Green top tube (GRNTT) • Lithium heparin • Lead determinations • Binds with lead • Not appropriate for cell morphology Lavender top tube (LTT) • EDTA • Hematology smears • Does not alter cell volume or morphology Light blue top tube (BTT) • Buffered sodium citrate • Coagulation determinations • Measures clotting time (e.g., von Willebrand’s disease, warfarin poisoning, activated partial thromboplastin time [APTT], prothrombin time [PT]) • Must be a perfect venipuncture stick to avoid activation of coagulation pathways • Tube must be filled to ensure proper dilution of blood with anticoagulant. Serum Samples • Invert tube to activate clotting, stand upright for 20 minutes, and then centrifuge for 15 minutes to ensure proper separation. Serum separator tube (SST), red/gray swirl top • Clot activator polymer gel • Blood chemistries • Serum is not able to mix with clotted blood once centrifuged. • The clotting activator can interfere with some lab tests (e.g., phenobarbital levels). Red (RTT) • Plain • Blood chemistries, serology, and blood banking • Serum and clotted blood can resuspend if the tube is tilted. • Serum should be separated after centrifugation to a separate plain container. • Glucose is metabolized at approximately 10% per hour when left in contact with cells. Tip: To determine the amount of fluid in a sample, evaluate a well-hydrated patient’s packed cell volume (PCV). A PCV of 50% will yield a sample with 50% cells and 50% fluid. Therefore, a 10-mL sample will yield 5 mL fluid. CHAPTER 4 / LABORATORY 75 Table 4.2 / Blood Chemistries Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Alanine Aminotransferase (ALT, SGPT) Source • Major: hepatocytes • Minor: cardiac muscle, skeletal muscle, pancreas Role • Amino acid metabolism Notes • Liver specific • There is a correlation between ALT levels and hepatic cell damage, but not liver function. • ↑ ALT often seen 2–3 days after hepatic insult and resolves by 14 days Canine/Feline • 5–65 U/L ↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, dilated cardiomyopathy, canine/feline, ehrlichiosis, endocardiosis, exocrine pancreatic insufficiency, feline hypertrophic cardiomyopathy, hepatic disease/ failure, hepatic lipidosis, hyperadrenocorticism, hyperparathyroidism, hypertension, hyperthyroidism, hypoadrenocorticism, pancreatitis, peritonitis, pyometra, Rocky Mountain spotted fever, thrombocytopenia, toxoplasmosis Handling • Hemolysis and lipemia; ↑ values Storage • Room temperature or refrigerator for 24 hours • 2 days at 68° F • 1 week at 32°–39° F • Do not freeze sample. Notes • Corticosteroids and anticonvulsants; ± ↑ values (canine) Albumin Source • Hepatocytes Role • Maintain osmotic pressure by retaining fluid within the vascular compartment. • Binding and transport protein Notes • Edema and effusions = ↓ values • 35–50% of total plasma protein • Best interpreted with globulin levels Canine • 2.3–4.0 g/dL Feline • 2.6–4.0 g/dL Danger level • 1.0 ↑ Rocky Mountain spotted fever ↓ Brucellosis, cholangitis/ cholangiohepatitis, ehrlichiosis, heartworm disease, hepatic disease/ failure, hepatic lipidosis, glomerular disease, hyperglobulinemia, hypertension, inflammatory bowel disease, pleural effusion, protein losing enteropathy, toxoplasmosis Handling • Extreme hemolysis and lipemia; ↑ values Storage • Keep sample covered to prevent dehydration; ↑ values • 1 week at 68° F • 1 month at 32–39° F Notes • Ampicillin; ± falsely ↑ values Albumin-to-Globulin Ratio (A : G ratio) Source • See Albumin and Globulin Role • See Albumin and Globulin Notes • First indicator of protein abnormality • Divide the albumin concentration by the globulin concentration. Canine • 0.6–1.2 Feline • 0.5–2.0 4 76 SECTION THREE: DIAGNOSTIC SKILLS Handling • See Albumin and Globulin Storage • See Albumin and Globulin Notes • See Albumin and Globulin Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Alkaline Phosphatase (Alk phos, ALP, SAP) Source • Major: liver (adult animals), bone (young animals) • Minor: kidneys, intestines Role • Assist in various chemical reactions Notes • Canines can often handle a 2–4-fold ↑ in value before significant signs of disease. • Interpretation is slightly different between canines and felines because of half-lives and amount of hepatic ALP present. Canine • 10–84 U/L Feline • 10–70 U/L ↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, drugs (glucocorticoids, barbituates, etc.), ehrlichiosis, hepatic disease/failure, hepatic lipidosis, hyperadrenocorticism, hyperparathyroidism, hypertension, hyperthyroidism, pancreatitis, pyometra, Rocky Mountain spotted fever, thrombocytopenia, toxoplasmosis Handling • Do not use EDTA or oxalate coagulants. Storage • At room temperature >24 hours; ↑ values • 8 days at 32°–39° F Notes • N/A Ammonia Source • Liver and muscle Role • Byproduct of the breakdown of proteins, amines, amino acids, nucleic acids, and urea Notes • N/A Canine • 45–120 μg/dL Feline • 30–100 μg/dL Danger level • >1,000 (canine) ↑ Cholangitis/cholangiohepatitis, hepatic disease/failure, hepatic lipidosis Handling • Heparinized sample preferred • Centrifuge and pour off plasma immediately. Storage • Store on ice and assay within 1 hour. • Freeze immediately and assay within 2 days. Notes • Vein occlusion for an extended period or strenuous exercise; ↑ values • Antibiotics, enemas, lactulose, diphenhydramine, parenteral amino acids, narcotics, diuretics, or blood transfusions may alter laboratory results. Amylase Source • Major: pancreas • Minor: liver and small intestines Role • Breakdown of starches and glycogen in sugars Notes • ↑ values are not always indicative of severity of disease nor specific for pancreas Canine • 300–1,500 units Feline • 500–1,500 units ↑ Pancreatitis, peritonitis, chronic renal failure, toxoplasmosis Handling • Hemolysis; ↑ values • Lipemia; ↓ values • Do not use EDTA Storage • 7 days at 68° F • 1 month at 32°–39° F Notes • Corticosteroids; ± ↓ values • Saccharogenic method; ± false ↑ values (canine) CHAPTER 4 / LABORATORY 77 4 Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Anion Gap (AG) Source • N/A Role • To differentiate causes of metabolic acidosis Notes • To calculate: (Na+ − K+) − (Cl− + HCO3−) = AG Canine • 12–25 Feline • 13–25 Aspartate Aminotransferase (AST, SGOT) Source • Major: hepatocytes • Minor: cardiac and skeletal muscles, kidneys, pancreas and erythrocytes Role • Amino acid metabolism Notes • Not liver-specific; ↑ values may indicate liver damage, strenuous exercise, IM injections • Tends to parallel ALT values when caused by hepatic disease Canine • 16–60 U/L Feline • 26–43 U/L ↑ Cholangitis/cholangiohepatitis, congestive heart failure, diabetes mellitus, endocardiosis, feline dilated cardiomyopathy, feline hypertrophic cardiomyopathy, hepatic disease/ failure, hepatic lipidosis, hyperthyroidism, hypoadrenocorticism, peritonitis, toxoplasmosis Handling • Hemolysis and lipemia; ↑ values Storage • 2 days at 68° F • 2 weeks at 32–39° F Notes • N/A Bicarbonate (Venous TCO2) Source • All cells Role • Aids in transport of CO2 from tissues to the lungs • Bicarbonate/carbonic acid buffer system Notes • 95% of total CO2 measured Canine/Feline • 21–31 mEq/L ↓ Metabolic acidosis, acute renal failure Handling • Chill in ice water to prevent alteration of acid–base composition. Storage • Do not freeze, as it results in hemolysis. Notes • N/A Bilirubin Source • Hemoglobin via liver processing Role • N/A Notes • Byproduct of erythrocyte degradation • Total bilirubin is composed of conjugated and unconjugated bilirubin. • Not liver specific Canine/Feline • 0.0–0.5 mg/dL ↑ Cholangitis/cholangiohepatitis, hepatic disease/failure, hemobartonellosis, hemolytic anemia, hepatic lipidosis, hyperthyroidism, pancreatitis, peritonitis, toxoplasmosis Handling • Lipemia; ↑ values Storage • Not stable when stored in the light or at 68° F • 2 weeks at 32–39° F in the dark Notes • Total bilirubin may ↓ by 50%/hr with direct exposure to sunlight or artificial light. 4 78 SECTION THREE: DIAGNOSTIC SKILLS Associated Conditions Handling and Special Considerations Handling • Refer to N.a, K., Cl−, and HCO3− Storage • Refer to N.a, K., Cl−, and HCO3− Notes • Drugs used in combination may blunt the gap ↑. Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Blood Urea Nitrogen (BUN, SUN) Source • Amino acids via liver processing Role • N/A Notes • Byproduct of amino acid breakdown • 75% of the kidney must be nonfunctional before ↑ values are seen Canine • 6–29 mg/dL Feline • 10–35 mg/dL ↑ Canine/feline dilated cardiomyopathy, congestive heart failure, cystic calculi, ehrlichiosis, endocardiosis, hepatic disease/failure, hypertension, hyperthyroidism, hypoadrenocorticism, mastitis, pancreatitis, pyelonephritis, renal failure, Rocky Mountain spotted fever ↓ Cholangitis/cholangiohepatitis, hepatic disease/failure, hepatic lipidosis, overhydration, dietary protein restriction Handling • N/A Storage • 8 hours at 68° F • 10 days at 32–39° F Notes • 18-hour fast is recommended, because high-protein diets can cause ↑ values Calcium Source • Bones Role • Maintenance of neuromuscular excitability and tone • Inorganic ion transfer across cell membranes • Blood coagulation Notes • Hemoglobin and bilirubin; ↑ values with colorimetric test methods • Hypoalbuminemia; ↓ values Canine/Feline • 8.0–12.0 mg/dL Danger level • ≤7.0 mg/dL or ≥16.0 mg/dL ↑ Hyperparathyroidism, hypoadrenocorticism, neoplasia, renal failure ↓ Dystocia, eclampsia, hypoparathyroidism, pancreatitis, protein losing enteropathy, renal failure Handling • Hemolysis and contact with cork stoppers; ↓ values • Lipema; ↑ values • Citrate, oxalate, or EDTA anticoagulants; ↓ values Storage • 10 days at 68° F or 32–39° F Notes • N/A Chloride Source • Extracellular fluid Role • Acid-base balance • Maintenance of water distribution • Osmotic pressure in blood Notes • Hemoglobin and bilirubin; ↑ values with colorimetric test methods • Tends to parallel serum sodium Canine • 100–115 mEq/L Feline • 117–128 mEq/L ↑ Metabolic acidosis ↓ Canine dilated cardiomyopathy, constipation, aggressive diuretics, severe emesis, Rocky Mountain spotted fever Handling • Hemolysis and lipemia; ↓ values Storage • Stable if separated from blood cells Notes • Potassium bromide, acetazolamide, ammonium chloride, androgens, cholestyramine, lithium, demeclocycline and amphotericin; ↑ values CHAPTER 4 / LABORATORY 4 79 Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Cholesterol Source • Major: hepatocytes • Minor: adrenal cortex, ovaries, testes and intestinal epithelium Role • Steroid hormone production Notes • Helpful in screening for hypothyroidism and Cushing’s disease Canine 150–275 mg/dL Feline 75–175 mg/dL ↑ Diabetes mellitus, hepatic disease, failure, hyperadrenocorticism, hypertension, hypoadrenocorticism, hypothyroidism, pancreatitis, Rocky Mountain spotted fever ↓ Drugs, exocrine pancreatic insufficiency, hepatic disease/failure, protein losing enteropathy Handling • Hemolysis, fluoride, and oxalate; ± ↑ values, depending on testing method Storage • Very stable at 68° F if separated from blood cells Notes • Corticosteroids; ± ↑ values Creatine Kinase (CK) Source • Cardiac and skeletal muscle and brain tissue Role • Enzyme that cleaves creatine in muscle for energy utilization Notes • Peaks 6–12 hours after muscle injury and returns to normal in 24–48 hours unless damage is ongoing • Very specific, but almost too sensitive • Only large ↑ are clinically significant (≥10,000 U/L) or chronic elevations (≥2,000 U/L) indicating ongoing muscle damage Canine/Feline • 50–300 U/L ↑ Encephalitis, feline dilated cardiomyopathy, feline hypertrophic cardiomyopathy, hypothyroidism, myasthenia gravis, polymyositis Handling • Severe hemolysis, icterus, IM injections; ↑ values • EDTA, citrate, fluoride, exposure to sunlight, and delayed analysis; ↓ values Storage • Not stable, do not freeze; analyze as soon as possible Notes • Exercise, recumbency, IM injections; ± ↑ values Creatinine Source • Skeletal muscle Role • N/A Notes • Byproduct of creatine degradation • 75% of the kidney must be nonfunctional before ↑ values are seen Canine • 0.6–1.6 mg/dL Feline • 1.0–2.0 mg/dL ↑ Canine/feline dilated cardiomyopathy, congestive heart failure, drugs, ehrlichiosis, endocardiosis, hypertension, hyperthyroidism, hypoadrenocorticism, severe muscle damage, pancreatitis, pyelonephritis, renal failure, Rocky Mountain spotted fever, toxoplasmosis Handling • N/A Storage • 1 week at 86–98.6° F Notes • Exercise, active muscle wasting, and meal containing meat; mild ↑ values Fibrinogen Source • Hepatocytes Role • Clot formation Notes • No fibrinogen found in serum, because it is removed from the plasma by the clotting process • Used mostly in cattle and horses Canine • 100–245 mg/dL Feline • 110–370 mg/dL ↑ Cholangitis/cholangiohepatitis, hepatic failure, severe inflammation ↓ DIC, liver failure/end stage Handling • Heparin; ↓ values Storage • Several days at 68° F • Several weeks at 32–39° F Notes • N/A 4 80 SECTION THREE: DIAGNOSTIC SKILLS Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Gamma Glutamyltranspeptidase (GGT) Source • Major: hepatocytes • Minor: kidneys, pancreas, intestines, and muscle cells Role • Enzyme: function unknown Notes • Values typically parallel ↑ in ALP; can be less influenced by secondary nonhepatic conditions or enzymeinducing drugs • Slightly more sensitive and specific for feline hepatic disease than canine Canine • 2–10 U/L Feline • 1–8 U/L ↑ Anterior uveitis, brucellosis, deep pyoderma, ehrlichiosis, feline immunodeficiency virus, hepatic disease/failure, meningitis, pleural effusion, pyometra Handling • N/A Storage • 2 days at 68° F • 1 week at 32–39° F Notes • Corticosteroids or anticonvulsant therapy; ± ↑ values Globulins Source • α-Globulins: hepatocytes • β-Globulins: hepatocytes • γ-Globulins: plasma cells Role • α- and β-globulins: transport and bind proteins • γ-Globulins: antibody Notes • Total serum globulin concentration = total serum protein concentration − albumin concentration Canine • 2.7–4.4 g/dL Feline • 2.6–5.1 g/dL ↑ Diabetes mellitus, hepatic failure, hyperadrenocorticism, hypertension, hyperthyroidism, immune mediated disease, neoplasia, pancreatitis, polyconal gammopathies, renal failure, acute ↓ Acute blood loss, heartworm disease, protein losing enteropathy/ nephropathy Handling • Hemolysis and lipemia; ↑ values Storage • See Albumin and Total Protein Notes • Dehydration; ↑ values • Neonatal animals are 60–80% of adult values; ↓ values Glucose Source • Dietary intake and gluconeogenesis or glycogenolysis by the liver Role • Cellular energy Notes • Indicator of carbohydrate metabolism or endocrine function of the pancreas Canine • 65–130 mg/dL Feline • 70–125 mg/dL Danger level • ≤60 mg/dL ↑ Diabetes mellitus, hypertension, hyperthyroidism, hyperadrenal, hypoparathyroidism, pyelonephritis, renal failure ↓ Dystocia, hepatic failure, failure, hypoadrenocorticism, insulinoma, neoplasia, peritonitis, sepsis Handling • GTT at 6–10mg/mL of blood as a glucose preservative Storage • Separate from blood cells immediately (<30 minutes) • 8 hours at 68° F • 72 hours at 32–39° F Notes • 16–24-hour fast is recommended, except if hypoglycemia suspected • Glucose levels can drop by 10%/hr if not separated from the blood cells • Stress; ↑ values CHAPTER 4 / LABORATORY 81 4 Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Inorganic Phosphorus Source • Bones Role • Energy storage, release, and transfer, carbohydrate metabolism and composition Notes • Inversely related to calcium Canine • 3.0–7.0 mg/dL Feline • 3.5–6.1 mg/dL ↑ Bone lesions, chronic renal failure, toxins ↓ Emesis/diarrhea, fanconi syndrome, hepatic lipidosis, hyperparathyroidism, hypoadrenocorticism Handling • Hemolysis and lipemia; ↑ values Storage • Separate from blood cells immediately • 3–4 days at 68° F • 1 week at 32–39° F Notes • Anabolic steroids, furosemide, mannitol, minocycline, and IV KPO4 may alter values Lipase Source • Pancreas and gastric mucosa Role • Break down the long-chain fatty acids of lipids Notes • Value is not representative of severity of disease • Tends to parallel serum amylase Canine • 0–425 units Feline • 0–200 units ↑ Pancreatitis, hyperadrenocorticism, liver disease, renal disease, failure Handling • Lipemia; ↑ values • Do not use calcium-binding anticoagulants Storage • 1 week at 68° F • 3 weeks at 32–39° F Notes • Corticosteroids; ± ↑ values Lipids/Triglycerides Source • Diet; intestinal absorption Role • Fat metabolism • Stimulus of intestinal lymph flow Notes • Animals at an ↑ risk are obese, high dietary intake of fats and genetic predisposition (e.g., Miniature Schnauzer and Himalayan cats Canine • 50–150 mg/dL Feline • 17–50 mg/dL Danger level • >1,000 mg/dL ↑ Diabetes mellitus, hyperlipidemia, hypothyroidism, pancreatitis, postprandial ↓ Lymphangectasia, protein-losing enteropathy Handling ↑ Lipemia; ↑ values Storage • N/A Notes • 12-hour fast recommended Magnesium Source • Bones Role • Activator of enzyme systems and involved in production and decomposition of acetylcholine Notes • ↑ Bilirubin can cause ↑ values of magnesium Canine • 1.8–2.4 mg/dL Feline • 2.0–2.5 mg/dL Danger Level • <1.0 or >10.0 mg/dL ↑ Hypoadrenocorticism, renal failure ↓ Metabolic conditions Handling • Hemolysis and metal containers; ↑ values • Only heparin anticoagulants should be used. Storage • Samples are very stable. Notes • N/A 4 82 SECTION THREE: DIAGNOSTIC SKILLS Table 4.2 / Blood Chemistries (Continued) Chemistry Definition Normal Range Associated Conditions Handling and Special Considerations Potassium Source • Intracellular fluid Role • Muscular function, respiration, cardiac function, nerve impulse transmission, and carbohydrate metabolism Notes • N/A Canine • 4.0–5.7 mEq/L Feline • 4.0–5.8 mEq/L Danger level • ≤2.5 or ≥7.5 mEq/L ↑ Diabetes mellitus, hypoadrenocorticism, massive tissue trauma, acute renal failure, urethral obstruction ↓ Canine/feline dilated cardiomyopathy, congestive heart failure, constipation, diabetes mellitus, gastrointestinal losses, hepatic lipidosis, peritonitis, renal failure Handling • Hemolysis (esp. Akitas) and refrigeration of an nonseparated sample; ↑ value Storage • Do not freeze nonseparated samples. • Stability is not known. Notes • Plasma is the preferred sample. Sodium Source • Extracellular fluid Role • Water distribution, body fluid osmotic pressure maintenance, and pH balance Notes • “Pseudohyponatremia” seen in cases of hyperlipidemia or severe hyperproteinemia Canine • 140–158 mEq/L Feline • 145–160 mEq/L ↑ Dehydration, heat stroke ↓ Canine dilated cardiomyopathy, congestive heart failure, gastrointestinal losses, hypoadrenocorticism, chronic renal failure, Rocky Mountain spotted fever Handling • Heparin; ↑ value • Hemolysis; ↓ value Storage • Stability is not known. Notes • Diuretic drugs; ↓ value Total Protein (TP) Source • See Albumin and Globulins Role • Oncotic blood pressure, transport mechanism, and immunity Notes • Composed of albumin and globulins Canine • 5.4–7.6 g/dL Feline • 6.0–8.1 g/dL ↑ Dehydration, gammopathy ↓ Acute blood loss, overhydrated Handling • Severe hemolysis and sample dehydration; ↑ value Storage • Keep sample covered to prevent dehydration. • Stability is not known. Notes • See Albumin and Globulins BONE MARROW EVALUATION Bone marrow evaluations can be used to diagnose, to stage certain neoplasias, or to monitor conditions and the body’s response to treatments. The collection and preservation of bone marrow samples are critical to producing diagnostic slides. Properly collected and prepared slides are often evaluated in-house for a preliminary diagnosis before receiving a confirmation from a cytopathologist. Bone Marrow Collection, Handling, Storage, and Transport Tips Collection • Bone marrow samples degenerate rapidly after collection: neutrophils are the first to take on morphologic changes resembling neoplasia. • Samples should be obtained and prepared within 30 minutes of an animal’s death. CHAPTER 4 / LABORATORY 83 4 Skill Box 4.1 / Supplies for Bone Marrow Collection • Surgical preparation materials • Place bone marrow aspirate immediately into an EDTA lavender top tube if slides cannot be made immediately. • Sterile surgical supplies (e.g., gloves, drapes) • Smears must be made within 30 seconds if an EDTA/isotonic solution is not used, to avoid clotting and cell morphology distortion. • Analgesic/anesthetic drugs • Allow the slides to air dry. • Samples must be stained as soon as possible to retain accurate morphology. 3 • 16–18 gauge, 1–1 /4-inch bone marrow biopsy needle 4 Handling • Scalpel blade • Staining typically requires 2 times the usual stain contact time to reach adequate staining. • 12 or 20 mL syringe • Clean microscope slides • 10–20 mL syringe with 2–3% EDTA/isotonic fluid solution Tip: Injecting 0.35 mL isotonic solution into a 7-mL EDTA blood collection tube produces 0.42 mL of 2.5% EDTA/isotonic fluid solution. Skill Box 4.2 / Smear Techniques Technique Definition/Uses Procedure General Information Smear Without EDTA • Samples collected using a clean, dry syringe 1. Hold a slide at a 45–70° angle. 2. Drip the marrow sample down the tilted slide, allowing the marrow flecks to adhere to the slide. 3. With the first slide laying flat, place a second slide on top, allow the drop to spread, and gently pull each slide horizontally in opposite directions. 4. Slides are air-dried and then stained. • Sample must be smeared within 30 seconds of collection. Smear With EDTA • Samples collected using an EDTA/ isotonic solution–filled syringe 1. Sample collected into an EDTA/isotonic solution syringe is expelled onto a Petri dish. 2. Tilt the Petri dish to allow the fluid to drain to the bottom and the marrow flecks to remain adhered to the dish. 3. Using a PCV tube, collect a marrow fleck/spicule and gently place it on a glass slide. 4. Place a coverslip at a 45° angle on the slide so that the corner of the coverslip hangs off the slide. 5. Pull the corner of the coverslip to make a smear of the marrow fleck. 6. Slides are air-dried and then stained. • Sample must be smeared within a few minutes of collection. Note: Make some slides using no pressure and some using gentle digital pressure placed on the coverslip. 84 SECTION THREE: DIAGNOSTIC SKILLS 1. Prepare a slide with stain. Storage 2. Scan the slide, using ×4 magnification. • Slides need to be completely dry before placing in a slide holder. a. b. c. d. Transport • Padding should be placed around both sides of the slide holder to prevent breakage (e.g., bubble wrap, padded envelopes). • Do not mail slides with bottles containing formalin, because the fumes may alter the staining capabilities of the slides. Verify adequate staining. Verify proper slide preparation. Determine the cellularity. Determine the quantity and maturation of megakaryocytes. 3. Examine the slide, using ×10 magnification. a. Cell size b. Cell type Evaluation 4 4. Examine the slide, using ×40 magnification. An air-dried slide should quickly be evaluated with new methylene blue to verify the presence of marrow elements (e.g., megakaryocytes) and its diagnostic quality. If the slide is not adequate, further samples should be taken. Once quality slides are available, a stepwise approach should be taken to ensure a thorough evaluation is completed. a. Chromatin pattern b. Nucleoli 5. Examine the slide, using oil immersion magnification. a. Myeloid:erythroid ratio Table 4.3 / Bone Marrow Evaluation Definition Examination Classification Cellularity Proportion of cells compared to fat cells Low power (×4–10) Proportion • Normocellular: 30–70% • Hypercellular: >50–70% • Hypocellular: <30–50% Megakaryocytes Quantity, maturation, and morphology Low power (×4–10) Quantity • Hypoplasia: <3/large fleck • Hyperplasia: >50/large fleck Maturation • Mature: >50% Erythrocytes Quantity, proportions, and morphology Low and high power (×10–100) Quantity • Rubricyte: 60–70% • Metarubricyte: 30–35% • Prorubricyte: 2% • Rubriblast: <1% Morphology • Karyolysis, pyknosis of immature cells, cytoplasmic or vacuolation, megaloblastic change CHAPTER 4 / LABORATORY 85 Table 4.3 / Bone Marrow Evaluation (Continued) Examination Classification Granulocytes Quantity, proportions, and morphology Low and high power (×10–100) Quantity • Metamyelocyte, band neutrophils, segmented neutrophils: 80% • Myeloblast, promyelocyte, myelocyte: 20% Morphology • Basophilic cytoplasm, vacuolation Myeloid:Erythroid Ratio 300–500 cells are evaluated in differing areas and classified as either myeloid or erythroid High power (×100) • Normal: slightly > 1 : 1 Organisms Identification High power (×100) • Microorganisms: Histoplasma capsulatum, Toxoplasma gondii, Cytauxzoon felis, Erlichia sp. • Parasites: Mycoplasma sp., Babesia sp. Note: Lymphocytes, plasma cells, monocytes, macrophage, and iron storage can also be evaluated. Table 4.4 / Cell Type Identification (See Figure 4.1, 4.2, and 4.3, CP-3) Cell Type Erthyrocytes 4 Definition 86 Appearance Rubriblast • • • • 1–2 Blue nucleoli Large, round, dark purple nucleus with smooth edges Fine granular, linear chromatin Distinct blue tint Prorubricyte • • • • Smaller than rubriblasts Round nucleus with smooth edges Coarse and thickened chromatin Reddish tinge Rubricyte • • • • Smaller than prorubricyte Dark clumps of coarse chromatin that begin to disappear Disappearing nucleoli Redder Metarubricyte • Larger than a mature RBC • Very dark, pyknotic nucleus • Chromatin and nucleoli are gone Reticulocyte • • • • SECTION THREE: DIAGNOSTIC SKILLS Large Nonnucleated Basophilic stippling when stained Residual, nonfunctional RNA Table 4.4 / Cell Type Identification (See Color Plates 4.1, 4.2, and 4.3) (Continued) Cell Type Myeloblast • • • • • Large Nongranular, blue–pink cytoplasm Round to oval, red nucleus Chromatin with stippled pattern 1–2 pale blue nucleoli Progranulocyte/Promyelocyte • • • • ↑ Cytoplasm with small, pink granules Dark nucleus Chromatin is dark and lacy in pattern ± Nucleoli Myelocyte • • • • Metamyelocyte • Indented or U-shaped nucleus • Cytoplasm stains light blue • Can be confused with monocytes of peripheral blood Band • U-shaped nucleus with smooth edges • ± Chromatin clumps present • Cytoplasm stains light blue Megakaryoblast • Not commonly distinguished in bone marrow samples because of size and number present • 2 reddish nuclei • Small amount of basophilic cytoplasm Promegakaryoblast • Dividing nuclei • Deep blue cytoplasm • 2–4 Nucleoli Megakaryocyte • Extremely large • Abundant, deep blue to pale blue granular cytoplasm • >4 Nucleoli Granulocyte Platelet Appearance 4 Oval nucleus Chromatin is dense with a coarse pattern Cytoplasm stains gray–blue Granules take on stain • Eosinophil—red granules • Canine: pleomorphic • Feline: rod-shaped • Basophil—blue granules • Canine: round, red–purple, and few to many • Feline: oval, lavender, and fill cytoplasm • Can be confused with monocytes of peripheral blood CHAPTER 4 / LABORATORY 87 Interpretation 4 Once a slide has been evaluated, the results are interpreted in conjunction with the results of the complete blood count (CBC). Interpretation may lead to a definitive diagnosis or be just 1 more step in the diagnostic path. Depending on the findings, additional tests may be indicated or an initial treatment plan may be established. Even though the preliminary diagnosis can be made by the veterinarian, it is recommended that these slides be sent to a cytology laboratory for confirmation and staging by a board-certified clinical pathologist/hematologist. cinoma), the stage of disease, and its prognosis. Although the final diagnosis must lie in the hands of the veterinarian, the technician may make crucial evaluations and interpretations of the slide material, aiding the veterinarian in the diagnosis. Cytology Collection, Handling, Storage, and Transport Tips Collection • Multiple collection attempts at multiple sites from the lesion should be made to ensure a representative sample. • Adequate pressure must be used with fine-needle aspiration (FNA) to ensure retrieval of cells. CYTOLOGY Cytology is performed in a clinical setting on a day-to-day basis. A technician well trained in cytology can quickly and easily make preliminary findings. These findings may aid in the distinction in the type of cell (e.g., adenocar- • Excessive negative syringe pressure or prolonged aspiration often leads to blood contamination and nondiagnostic slides. • Several slides should be made to allow different staining techniques. Skill Box 4.3 / Collection Techniques Technique Uses Procedure Comments Imprints • External lesions or fresh tissue samples from a surgical biopsy or necropsy 1. Blot the lesion or area to be imprinted with a clean, dry gauze. 2. Touch the lesion against a clean glass slide to make an imprint. • Can repeat several times on 1 slide. • Imprint ulcers before and after cleaning. • Typically collects the fewest number of cells with the greatest amount of contamination Scrapings • External lesions or tissues from surgical biopsy or necropsy 1. Clean lesion and blot dry. 2. Hold scalpel perpendicular to lesion. 3. Pull the blade toward oneself several times in a scraping motion. 4. Transfer the material to the middle of a glass slide with the scalpel blade and smear. • Collects a large number of cells and possibly a large amount of bacterial contamination and inflammation Swabs • Fistulous tracts and vaginal collections 1. Moisten a sterile swab with saline. 2. Gently roll the swab against the inside wall of the tract or vagina. 3. Gently roll the swab across a slide to transfer material in a thin smear. • Only alternative for tract-like lesions • ↑ Cell damage with rough or improper handling 88 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.3 / Collection Techniques (Continued) Technique Fine Needle Biopsya Aspirate a Nonaspirate Uses Procedure Comments • Lesions 1. Isolate and firmly hold the tumor. 2. Insert the needle into the tumor and apply strong negative pressure by pulling the plunger 3/4 of the way back and release pressure. 3. Redirect the needle to a different part of the tumor and again apply pressure; continue this several times in different locations. 4. Quickly smear the contents, using 1 of the smear techniques. (See Skill Box 4.5 Smear Techniques, page 90.) • If the tumor is large enough, negative pressure may be maintained while the needle is being redirected. • Avoids superficial contamination, but with ↑ contamination of tissues surrounding the tumor during aspiration • ↑ Blood contamination with certain types of tumors • Allows for collection from multiple locations within the lesion 1. Isolate and firmly hold the tumor. 2. Insert the needle only into the tumor and rapidly move the needle up and down while maintaining the same track. 3. Remove the needle and attach an air-filled syringe and quickly expel the contents onto a clean glass slide. 4. Smear the contents, using 1 of the smear techniques. (See Skill Box 4.5 Smear Techniques, page 90.) • Avoids superficial contamination, but with ↑ contamination of tissues surrounding the tumor during aspiration • Enough material collected for only 1 smear, which may reduce diagnostic yield • Any mass or solid lesion that is of large enough size to isolate • Ultrasound-guided biopsy of deep tissues • Highly vascular lesions Fine needle biopsy to the center of a mass typically yields necrotic debris and inflammatory cells, peripheral locations may produce the best results. Difficult in small masses ≤10 mm. Skill Box 4.4 / FNB Needle and Syringe Selection • The softer the tissue being aspirated, the smaller are the gauge of needle and syringe. • Do not use needles larger than 21 gauge, because they produce core biopsies and have a greater likelihood of blood contamination. • 12-mL syringes are a safe bet for all tumors. Handling • The material obtained must be prepared and smeared on a slide immediately to avoid drying, clumping, and clotting. • Do not allow the smear to reach the edges of the slide if possible. • Rapidly dry the slide after smearing by waving in the air or using a blow dryer. • Slides should be marked as to which side is the top by using the patient’s information. • 2–3 air-dried unstained slides and 2–3 air-dried stained slides should be prepared when sending to the laboratory. The stained slides are a precaution for those cells that do not hold up well unstained for extended periods. • Fluid samples should be sent with prepared slides if possible. CHAPTER 4 / LABORATORY 89 4 Skill Box 4.5 / Smear Techniques The most common error in cytology is sample handling by the laboratory technician. An improperly prepared slide may contain ruptured cells or areas too thick to read, or the sample may dry before it is smeared. All of these errors may lead to improper evaluation, but they can be remedied by proper technique and care on the part of the laboratory technician. 4 Technique Definition/Uses Procedure Blood Smear Technique • Produces a thin layer of fluid material across the slide • Fluid samples 1. Expel the aspirate material onto a glass slide. 2. Place the second glass slide at a 30–40° angle to the first slide in front of the material. 3. Pull the second slide back into the material and then gently, but swiftly, push across to the end of the first slide. • Rest the “smearing” slide against a fingertip to push across allows a gentle and smooth movement. • The end of the smear should have a feathered edge and not run off the edge of the slide. Squash Preparation • Produces well-smeared slides • Thicker samples (e.g., bone marrow aspirates) 1. Expel the aspirate material onto a glass slide. 2. Place a second glass slide on top of the material at a right angle. 3. Without applying any downward pressure, quickly and smoothly slide the top slide across the bottom slide to smear the material. Squash-Modified Preparation • Produces well-smeared slides with a ↓ tendency for cell rupture • Thicker samples (e.g., bone marrow aspirates) 1. Follow steps 1 and 2 above. 2. Rotate the top slide 45° and then lift up. Combination Technique • A combination using the squash preparation and the blood smear technique • Any sample 1. Expel the aspirate material onto a glass slide. 2. Mentally divide the material into 3 sections and do a blood smear technique on one third of the slide and a squash preparation on the opposite third. Starfish Preparation • Prevents destruction of fragile cells • Any sample 1. Expel the aspirate material onto a glass slide. 2. Using the tip of the needle, spread the material out into the shape of a starfish. 90 SECTION THREE: DIAGNOSTIC SKILLS Storage • Slides need to be completely dry before placing in a slide holder. Transport • Padding should be placed around both sides of the slide holder to prevent breakage (e.g., bubble wrap, padded envelopes). • Do not mail slides with bottles containing formalin, because the fumes may alter the staining capabilities of the slides. • Protect the slides from moisture as the sample may become distorted. Evaluation Once each slide has been properly collected and prepared, it is often evaluated in the clinic for a preliminary diagnosis. The technician is an integral part of this procedure by evaluating the slide and noting any alterations. The DVM then confirms the slide contents and makes a preliminary diagnosis. The slide is sent to a reference laboratory for official diagnosis. 1. Prepare a slide with stain. 2. Scan the entire slide using ×4 magnification. a. Verify adequate staining. b. Check for staining features and artifacts. c. Check for overall cellularity and localized areas of cellularity. d. Check for crystals, foreign bodies, parasites, and fungal hyphae. 3. Examine the slide, using ×10 magnification. a. Cell size b. Cell type c. Cellularity 4. Examine the slide, using ×40 magnification. a. Chromatin pattern b. Nucleoli 4 5. Examine the slide, using oil immersion magnification. a. Cell inclusions b. Cell organisms c. Mitotic figures Tip: Placing a drop of immersion oil on a prepared slide (excluding a wet mount) covered by a coverslip enhances the clarity of the slide contents. To increase magnification to ×100, another drop of immersion oil can be placed on top of the coverslip and examined. To save the slide for later evaluation, the coverslip can be gently slid off horizontally to avoid damaging the slide’s contents. CHAPTER 4 / LABORATORY 91 Table 4.5 / Cytologic Criteria of Malignancy Any slide showing 1 or a combination of the following cellular changes should be carefully reviewed for potential malignancy. A cytology laboratory should be consulted for clarification if needed. Nuclear characteristics have proven to be the most reliable source of determining malignancy. However, all aspects of the cells should be evaluated. Some types of malignant cells do not routinely show any of the following characteristics; therefore, all other aspects of the complete workup should be viewed simultaneously. 4 Cytologic Characteristics Appearance Tumor Cell Types Nuclear • • • • • • Anisokaryosis Macrokaryosis Variation in nuclear : cytoplasmic ratio Coarse chromatin pattern that clumps Irregular nuclear pattern Abnormal size, shape, and appearance of nucleoli • Irregular nuclear membrane Epithelial • Round nucleus with a smooth to slightly coarse chromatin pattern and usually centrally located • 1 or more nucleoli Mesenchymal • Oval nucleus and centrally located Round cell • Centrally or eccentrically located Cytoplasmic • Vascuolization • Variable amount of cytoplasm from cell to cell • Basophilia with Wright’s stain • Abnormal cytoplasmic boundaries Epithelial • ↑ Cytoplasm with secretory products or vacuolated Mesenchymal • Abnormal cytoplasmic boundaries and extensions • Moderate amount Round cell • Well-defined cytoplasmic boundaries • Variable amount, granularity, and vacuolization Structural • Anisocytosis • Macrocytosis • Pleomorphism Epithelial • Large to very large cells • Round to oval to caudate cells, easily exfoliating into sheets, clusters, or clumps Mesenchymal • Small to medium cells • Spindle-shaped cells hard to exfoliate • Individual cells or in disorganized clusters Round cell • Small to medium cells • Round to oval cells; easy to exfoliate individual cells 92 SECTION THREE: DIAGNOSTIC SKILLS Table 4.5 / Cytologic Criteria of Malignancy (Continued) 4 Figure 4.4 Cytologic criteria of malignancy. Note: Courtesy of Dina A. Andrews, DVM, Ph.D, DipACVP. CHAPTER 4 / LABORATORY 93 Table 4.6 / Specific Tumor Cells The following chart gives a general description of common tumor types. Multiple variations can be seen because of location, duration, and malignancy. Each cell should be evaluated in lieu of the rest of the slide and the general findings of the animal. The diagnosis of a particular condition must be made by the veterinarian. Tumor Type Epithelial Mesenchymal Basophilic cytoplasm with ± vacuoles with secretory products Variable nuclear size and nuclear : cytoplasm ratio Nuclei often eccentrically displaced to the periphery of the cells Round to oval cells appearing in clusters Variable nucleolar shape and number Mammary Adenocarcinoma • • • • • Perianal Adenoma • Hepatoid appearing in clumps • Round to oval nuclei with 1–2 nucleoli • Abundant, foamy, and gray to tan cytoplasm with ± granules Sebaceous Gland Tumor • • • • Squamous Cell Carcinoma • Basophilic cytoplasm to abundant, pale cytoplasm • Large nuclei with clumped chromatin • Variable nuclear : cytoplasm ratio Lipoma • Large cells distended with fat or lacy, collapsed cells Osteosarcoma • Variably sized nucleus with clumped chromatin • Spindle-shaped • Abundant, foamy basophilic cytoplasm Soft Tissue Sarcoma • Anisocytosis or spindle shaped • Dark blue cytoplasm with ± vacuoles and pink granules • Variable number and size of nucleoli 4 94 Appearance SECTION THREE: DIAGNOSTIC SKILLS Large cell Nucleus with a slightly coarse chromatin pattern ↑ Nuclear : cytoplasm ratio ± Basophilic and foamy cytoplasm Table 4.6 / Specific Tumor Cells (continued) Round Cell Tumor Tumor Type Appearance Histiocytoma • Color Plate 4.5, CP-4 • • • • • Anisocytosis Poikilocytosis Variable amount of pale blue cytoplasm ↑ Nuclear:cytoplasm ratio Round, oval, or irregularly shaped nuclei with lacy or finely stippled chromatin pattern Lymphoma • Color Plate 4.6, CP-4 • • • • Dense nuclear margins with basophilic cytoplasm ↑ Nuclear:cytoplasm ratio Granular chromatin ≥1 Nucleolus Mast Cell Tumors • Color Plate 4.7, CP-4 • • • • Anisocytosis Round to oval nuclei, stain palely Fine to coarse, blue-black to reddish-purple granules within cytoplasm Variable nuclear:cytoplasm ratio depending on differentiation and grade Melanoma • Green-black to brown granules that are irregular in shape and size in cytoplasm • Poikilocytosis Plasma Cell Tumor • • • • Interpretation Once a slide has been evaluated, the results should confirm an inflammatory and/or neoplastic process. The distinction of inflammation alone often will enable the veterinarian to determine an initial protocol and treatment plan. 4 Oval to round cells with coarse, clumped chromatin 1 small nucleolus ± Basophilic cytoplasm Nonstaining Golgi apparatus eccentrically placed If the slide is found to have neoplastic cells, they are then reviewed against the criteria of malignancy. A preliminary diagnosis on cell type, associated disease, and malignancy can be made by the veterinarian. Often, the results are sent to a cytology laboratory for confirmation and staging. CHAPTER 4 / LABORATORY 95 Table 4.7 / Fecal Cytology Appearance Clostridium sp. • Color Plate 4.8, CP-4 • • • • Giardia • Color Plate 4.9, CP-5 Trophozoites • Pear-shaped with a concave ventral surface • Two outlined nuclei resembling eyes along with a nose and mouth, which are axonemes and median bodies • Forward or “falling leaf” motility • Size: 6–10 μm Cysts • Crescent-shaped indentation when collapsing in fecal float solution • Nuclei, cyst wall, and axonemes seen • Size: 11–13 μm Curved or Spiral Bacteria Organism Yeast 4 Fecal cytology is an important diagnostic tool for identifying inflammatory cells and potentially pathogenic organisms of the GIT. It is indicated in diarrheic animals, either acute or chronic. The first step is to assess the presence and quantity of bacteria. One predominant bacteria may indicate it as an pathogenic organism and a bacterial culture should be pursued. Some conditions may have more than 1 predominant bacteria (e.g., malabsorption, maldigestion). The presence of small numbers of epithelial cells may be found in normal animals. However, the presence of neutrophils or eosinophils may be indicative of inflammatory disease (e.g., Salmonella, Campylobacter sp., eosinophilic colitis). Fecal cytology may also reveal protozoal (e.g., Giardia) or fungal (e.g., Histoplasma sp.) organisms. Fecal cytology is set up in 1 of 2 ways: wet prep or dry prep. See Skill Box 4.16 Endoparasite Examination Methods page 134, for further information. 96 Large, gram-positive rods More easily recognized in the sporulated form “Safety pin” appearance, which represents a nonstaining spore within the sporangium (the body of the cell) >5 per ×100 field may indicate overgrowth Campylobacter • Color Plate 4.10, CP-5 • • • • • Treponeme and Spirillum Type (true spirochetes) • Color Plate 4.11, CP-5 • Gram-negative • Stiff corkscrew helical rods with tight spirals • Corkscrewing motility Brachyspira • Looser, sinusoid, thin spirals • Rapid, nematode-like movement; when attached to shed epithelial cells in large numbers resemble flagella Trichomonas sp. • Single nucleus and undulating membrane • Rolling and erratic motility, flexing axostyle visible, jerky movement • Can be confused with Giardia (feline; diarrheic) Candida-like • Color Plate 4.12, CP-5 • Rarely internal structures; smaller than Giarda cysts Cyniclomyes (Sarrharomycopsis) • Large elongated yeast with bipolar inclusions; sometimes see branching SECTION THREE: DIAGNOSTIC SKILLS Gram-negative Tiny, curved, gram-negative rods (not tightly spiraled) Two attached together as a “seagull” or “W” shape “Swarm of bees”: rapid and darting motility Size: 1.5–5 μm Vaginal Cytology Vaginal cytology is used in evaluating an animal’s stage of estrus cycle. Because of the constant changing of cellular structures during the estrus cycle, the evaluation of vaginal cells should be done every few days and in conjunction with a thorough medical history and examination (e.g., multiple, sequential samples increase accuracy of estrus stage estimation). Table 4.8 / Classifying Vaginal Cells Noncornified Squamous Epithelial Cells Appearance Parabasal cells • Small round cells with a small amount of cytoplasm • Round, distinct nuclei • Uniform in size and shape Intermediate cells • Large round cells with a large amount of cytoplasm • Round nuclei Superficial Intermediate cells • ↑ Cytoplasm that is irregular, folded, and angular • Smaller nuclei, pyknotic Cornified Squamous Epithelial Cells Vaginal Cells 4 Superficial cells • Large cells • ↑ Cytoplasm, folded and angular • Distinct edges As the cell ages • ± Nucleus (nucleated with young cells and anuclear with older/advanced cells) and vacuoles CHAPTER 4 / LABORATORY 97 Table 4.9 / Staging the Estrus Cycle Estrus Stage Definition Cell Appearance Anestrus • No physical changes • Does not attract or accept males • Duration: <4.5 months • Intermediate or parabasal cells • ± Neutrophils • ± Bacteria Proestrus • Swollen vulva, bloody vaginal discharge • Attracts, but will not accept males • Duration: 4–13 days Early • Noncornified squamous epithelial cells • Neutrophils and erythrocytes • ± Bacteria Late • Superficial intermediate cells and cornified epithelial cells • ↓ Neutrophils and ↑ erythrocytes • ± Bacteria Estrus • Swollen vulva and pinkish to straw colored discharge • Accepts males • Duration: 4–13 days Early • 90% Cornified squamous epithelial cells • ± Superficial intermediate cells • ± Erythrocytes • Bacteria Late • ↑ Neutrophils and ↓ erythrocytes • Bacteria Metestrus/Diestrus • Vulvar swelling and discharge • Does not attract or accept males • Duration: 2–3 months Early • Cornified squamous epithelial cells • ↑ Cytologic debris Late • Intermediate and parabasal cells • ± Neutrophils and erythrocytes 4 FUNCTION TESTS Function tests are used to force a system in the body to perform in a specific way (e.g., suppression or stimulation) to provide predictable results. Depending on the results, the information received will help to determine whether the system is functioning correctly. Most of these procedures require 98 SECTION THREE: DIAGNOSTIC SKILLS a specific protocol of fasting, injections, and blood drawing times; however, individual laboratories should be consulted regarding their specific protocol. As with any laboratory test, collection and handling remain the area of biggest human error as well as the area easiest to monitor and perform correctly. Table 4.10 / Function Tests Test Definition/Uses Normal Range Protocols Handling and Special Considerations Adrenocorticotropic Hormone (ACTH) Endogenous Plasma, Concentration Distinguishes between pituitarydependent hyperadrenocorticism (PDH) and adrenocortical tumors (ATs) and primary and secondary hypoadrenocorticism Canine • 2.2–25 pmol/L • <2.2 = AT • 2.2–10 = nondx • >10 = PDH • Fast for 12 hours. • Collect a blood sample. Handling/Storage • Lipemia; may interfere with the assay • Sample should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. • Send by overnight air on dry ice to testing laboratory. • Aprotinin can be added to the EDTA tube to inhibit the degradation of ACTH and remove the need to freeze sample. Notes • N/A Tube: LTT Amount: full tube Use: Hyperadrenocorticism, Hypoadrenocorticism ACTH Stimulation Test or ACTH Response Test Tube: SST or RTT Amount: 0.5 mL serum or plasma each sample The adrenal gland will respond to exogenous ACTH stimulation by glucocorticoid release in proportion to the glands’ size and development. This test measures actual cortisol hormone. Canine Pretest: • 0–10 μg/dL Posttest: • 8–22 μg/dL Feline Pretest: • 0.4–4.0 μg/dL Posttest: • 8–12 μg/dL • Obtain baseline sample. • Cosyntropin • Canines: 0.25 mg IM and felines 0.125 mg IM cosyntropin. • Draw blood sample 1 hour post for canines and 30 minutes and 1 hour post for felines. • ACTH gel • Give 1 unit/lb of ACTH gel IM. • Draw blood sample 2 hours post for canines and 1 and 2 hours post for felines. Handling/Storage • Delay in separation of serum/plasma from blood cells and lipemia; ↓ values • Sample should be immediately placed in an ice bath, centrifuged, transferred into a plastic tube, and frozen. Notes • Discontinue prednisone, prednisolone, cortisone, and fludrocortisone 24–48 hours before test. Evaluates the effect of exogenous ADH on the renal tubular ability to concentrate urine in the face of dehydration or water deprivation Canine/Feline • ↑ in urine specific gravity (USG) • Immediately after a water deprivation test; give 0.5 U/ kg vasopressin IM (max of 5 U) • Empty the urinary bladder and measure specific gravity and osmolality at 30, 60, 90, and 120 minutes Handling/Storage • N/A Notes • Withhold all food and water until the test has been completed. Use: Hyperadrenocorticism, Hypoadrenocorticism; screening and monitoring therapy ADH Response Test or Vasopressin Response Test Use: Diabetes insipidus; differentiates between central and nephrogenic diabetes insipidus CHAPTER 4 / LABORATORY 99 4 Table 4.10 / Function Tests (Continued) Test Definition/Uses Normal Range Protocols Handling and Special Considerations Ammonia Tolerance Test (ATT) Detect abnormal portal blood flow and liver dysfunction Canine Preammonia: • 44–116 μg/L Postammonia: • 85–227 μg/L Danger level • >1,000 μg/dL • Fast for 12 hours and give enemas to clear lower bowel • Obtain baseline sample • Give ammonium chloride at 0.1 g/kg (max of 3 g) • Orally dissolved in 20– 50 mL water and given by stomach tube • Rectally as a 5% solution • Orally as a powder in gelatin capsules • Draw heparinized blood samples at 30 to 45 (gelatin capsules) minutes post Handling/Storage • Centrifuged immediately, pour plasma off and analyze within 1–3 hours or freeze at −68° F Notes • Not recommended for felines • Do not perform if resting ammonia levels are already ↑, because it may cause hepatic encephalopathy. • Oral administration may cause regurgitation. • Vomiting may occur but does not invalidate test. • Venous occlusion, vigorous activity before, and muscle exertion during restraint; ↑ values • 3–10-fold ↑ indicates portosystemic shunts A dysfunctional hepatobiliary system allows ↑ levels of bile acids to be found systemically. This test is a very sensitive function test of hepatic and biliary abnormalities. Canine/Feline Fasted: • <5 μmol/L Postprandial: • <25 μmol/L • Fast for 12 hours. • Obtain a baseline sample. • Feed ≥2 Tbsp of a high-fat diet to a dog and ≥1 Tbsp to a cat. • Collect a blood sample 2 hours post. Handling/Storage • N/A Notes • Ursodeoxycholic acid; altered values • Hemolysis: ↓ values • Ileum disease and large-volume diarrhea; ↓ values A direct measurement of pancreatic lipase versus the general measurement of total serum lipase activity Canine • 1.9–82.8 μg/L • Fast for 12–18 hours. • Collect a blood sample. Handling/Storage • Separate serum and send sample on ice with a direct carrier to Texas A&M GI Lab. Notes • N/A Tube: GRNTT Amount: full tube 4 Use: Hepatic disease and portosystemic shunting Bile Acids Tube: SST Amount: 0.5 mL serum each Use: Hepatic disease, portosystemic shunting, and cholestatic disorders Canine Pancreatic Lipase Immunoreactivity (cPLI) Tube: SST Amount: 0.5 mL serum Use: Pancreatitis and Pancreatic mass 100 SECTION THREE: DIAGNOSTIC SKILLS Table 4.10 / Function Tests (Continued) Test Definition/Uses Normal Range Protocols Handling and Special Considerations Dexamethasone Suppression Test High-dose Differentiates pituitary-dependent hyperadrenocorticism (PDH) from adrenocortical tumors (ATs) in canines. The injected dexamethasone is expected to shut off ACTH production through negative feedback, as seen with PDH. This is also a diagnostic screening test for HAC in felines. Canine PDH: Pretest: • 1.1–8.0 μg/dL Posttest: • 0.1–1.4 μg/dL or ≤50% of pretest level AT: Pretest: • 2.5–10.8 μg/dL Posttest: • 1.4–5.2 μg/dL • Obtain a baseline sample. • Give 0.01 mg/kg dexamethasone IV. • Collect a blood sample at 4 (optional) and 8 hours post. Handling/Storage • N/A Notes • N/A Used to diagnose or confirm HAC Canine Pretest: • 1.1–8.0 μg/dL Posttest: • 0.1–0.9 μg/dL • (nondx 1.0–1.4 μg/dL) Feline Pretest: • 1–4 mg/mL Posttest: • <1.5 μg/dL • Obtain a baseline sample. • Give 0.01 mg/kg (canine) and 0.1 mg/kg (feline) dexamethasone sodium phosphate IV. • Collect a blood sample at 4 and 8 hours post. Handling/Storage • N/A Notes • Keep felines in a stress-free environment during testing. Folate is absorbed in the jejunum and cobalamin in the ileum. Reflect intestinal absorptive function and the status of the intestinal flora. Canine Folate • 3.5–11 μg/L Cobalamin • 300–700 ng/L Feline Folate: • 6.5–11.5 μg/L Cobalamin • 290–1,500 ng/L • Fast for 12 hours. • Collect a blood sample. Handling/Storage • Folate hemolysis; ↑ value • Avoid prolonged exposure to light and heat. Notes • N/A Adjunctive test used to diagnose DM and to monitor glycemic control during insulin therapy Canine • 370 μmol/L Feline • 375 μmol/L • Obtain a blood sample. Handling/Storage • N/A Notes • Corticosteroids, progestins, thiazide diuretics, growth hormone, dextrosecontaining fluids and morphine; ↑ value Tube: SST Amount: 0.5 mL serum each Use: Hyperadrenocorticism Dexamethasone Suppression Test Low-dose Tube: SST Amount: 0.5 mL serum each Use: Hyperadrenocorticism Folate and Cobalamin Tube: SST Amount: 1 mL serum Use: Intestinal bacterial overgrowth, malabsorption, exocrine pancreatic insufficiency, inflammatory bowel disease, or intestinal neoplasia Fructosamine Tube: SST or RTT Amount: 0.5 mL serum Use: Diabetes mellitus 4 CHAPTER 4 / LABORATORY 101 Table 4.10 / Function Tests (Continued) Test Definition/Uses Normal Range Protocols Handling and Special Considerations Prothrombin Time (PTH, PT) A vitamin K–dependent coagulation protein (factor) made by the liver. Evaluates extrinsic and common coagulation pathways Canine • 5–8 sec Feline • 8–11 sec • Collect a blood sample. Handling/Storage • Tube must be completely full. • Centrifuge at 3,000 rpm for 10 minutes, remove plasma. • If >24 hours to run test, spin sample, and freeze plasma. Notes • N/A Identifies an immune response specifically against muscle AchRs. Canine • <0.6 nmol/L Feline • <0.3 nmol/L • Collect a blood sample. Handling/Storage • Separate serum and ship overnight on ice/chilled. Notes • Corticosteroid therapy can lower serum antibody levels. Evaluates the ability of the thyroid gland to suppress pituitary TSH secretion followed by a drop in T4 secretion. Canine/Feline • ↓ in serum T4 after 72 hours of oral T3 • Obtain a baseline sample for T4 and T3. • Give 25 μg/cat of T3 orally TID, starting the next morning for 7 doses. • On the morning of the 3rd day, give 25 μg orally of T3 and redraw blood sample within 4 hours for T3 and T4. Handling/Storage • N/A Notes • Rise in T3 confirms owner’s compliance in giving medication. Evaluate the resting thyroid hormone concentration, a measurement of the total T4 or T3. Canine T4: • 1.0–4.0 μg/dL T3: • 0.5–1.8 ng/mL Feline T4: • 1.8–4.5 μg/dL T3: • 0.4–1.6 ng/mL • Collect a blood sample. Handling/Storage • N/A Notes • Corticosteroids, illness, estrus, pregnancy, obesity, stress; altered values • T3 is not as accurate in the early stages of disease. A measurement of thyroid hormone not bound to a protein (unbound) and available for entry into cells Canine • 0.3–0.5 ng/dL Feline • 0.8–5.2 ng/dL • Collect a blood sample. Handling/Storage • N/A Notes • Least likely to be affected by nonthyroidal diseases Tube: BTT Amount: 1.8 mL whole blood 4 Use: Liver disease and anticoagulant toxicity Serum Antibody Against Nicotinic AchRs Tube: SST Amount: 1 mL serum Use: Myasthenia gravis T3 Suppression Test Tube: RTT Amount: 0.1 mL serum Use: occult Hyperthyroidism Thyroid Hormone, Basal Serum (T4 and T3) Tube: SST Amount: 1 mL serum Use: Hyperthyroidism, Hypothyroidism Thyroid Hormone, Free (Free T4 and Free T3) Tube: SST Amount: 0.5 mL serum Use: Hyperthyroidism, Hypothyroidism 102 SECTION THREE: DIAGNOSTIC SKILLS Table 4.10 / Function Tests (Continued) Test Definition/Uses Normal Range Protocols Handling and Special Considerations Thyroid-Releasing Hormone (TRH) Stimulating Test or TRH Response Test TRH is responsible for the release of thyroid-stimulating hormone (TSH) from the anterior pituitary and the eventual synthesis of thyroid hormone. Evaluates thyroid gland function by the degree of change after the administration of TRH. Canine • >2 μg/dL post-TRH or ≥0.5 μg/dL above baseline T4 Feline • Little to no ↑ • Obtain baseline sample. • Give 0.1 mg/kg TRH IV. • Collect blood sample 4 and 6 hours post (canine) and 4 hours post (feline). Handling/Storage • N/A Notes • TRH administration typically causes hypersalivation, tachypnea, and vomiting up to 4 hours post-stimulation. TSH is responsible for stimulating the synthesis of thyroid hormones in the thyroid gland. Canine • 0.02–0.5 ng/mL • Collect a blood sample. Handling/Storage • N/A Notes • N/A Test of pancreatic digestive function. A ↓ amount of serum TLI is found when there is a ↓ in the amount of functioning pancreatic cells. Canine • 5–35 μg/L Feline • 17–49 μg/L • Fast for 12 hours. • Collect blood sample. Handling/Storage • Allow to clot at room temperature. • Serum is stored at −68° F. Notes • More sensitive and specific for pancreatitis than amylase/lipase Although urine creatinine stays relatively constant in an animal with stable kidney function, increased urine cortisol levels are seen with hyperadrenocorticism. Canine • <1.35 × 10−5 • Obtain urine sample. • Determine cortisol and creatinine concentrations. Handling/Storage • N/A Notes • Avoid stress while obtaining urine sample. • Obtain at home with a morning sample • False positives are common. To determine the significance of protein in the urine; not dependent on urine concentration Canine • <0.3 Feline • <0.6 • Obtain urine sample via cystocentesis. • Determine protein and creatinine concentrations. Handling/Storage • N/A Notes • Performed on a morning sample Tube: SST Amount: 0.5 mL serum each Use: Hyperthyroidism (feline), Hypothyroidism (canine) Thyroid-stimulating Hormone Concentration (endogenous TSH) Tube: SST Amount: 0.5 mL serum Use: Hypothyroidism Trypsin-like immunoreactivity (TLI) Tube: SST or RTT Amount: 1 mL serum Use: Exocrine Pancreatic Insufficiency, Pancreatitis Urine Cortisol:Creatinine ratio Amount: 3–4 mL urine Use: Hyperadrenocorticism Urine Protein:Creatinine Ratio Amount: 1 mL Cystocentesis sample Use: Glomerulonephritis and renal disease CHAPTER 4 / LABORATORY 103 4 Table 4.10 / Function Tests (Continued) Test Definition/Uses Normal Range Protocols Handling and Special Considerations Water-Deprivation Test To dehydrate the body to the point of signaling ADH release and the subsequent concentration of urine by the kidneys Canine • 1.045 Feline • 1.075 • A USG of 1.025 is considered an adequate response. • Stop either test when the animal loses ≥5% of body weight, becomes ill, or USG is >1.025. Gradual • Determine unrestricted daily water intake. • Measure USG and weigh animal. • Reduce water intake by 5% daily (not <66 mL/kg/day). • Measure USG and weigh animal daily. Abrupt • Empty urinary bladder and measure USG and weigh animal. • Withhold food and water until the end of the test. • Every 2–4 hours, empty urinary bladder, measure USG, and weigh animal. Handling/Storage • N/A Notes • Contraindications: dehydration, renal disease, and azotemia • A modified water-deprivation test is the ADH response test immediately after the standard water-deprivation test. • BUN should be monitored regularly throughout both tests. Use: Diabetes insipidus 4 HEMATOLOGY Even though many clinics send their blood samples out to reference laboratories for evaluation or use in-house automated machines, knowledge of how to perform a manual complete blood count (CBC) can be very useful in certain situations. For example, during emergency situations, when time is crucial, the technician may be asked to perform an in-house CBC—or when the automated machine is malfunctioning. The results will provide the veterinarian with crucial information regarding the patient’s hematology status (e.g., anemia, infection, and neoplasia). See Under Blood Chemistries for Blood Collection, Handling, Storage, and Transport Tips. 104 SECTION THREE: DIAGNOSTIC SKILLS A CBC consists of RBC and WBC evaluation, PCV, TP, hemoglobin (Hgb) concentration, differential, platelet estimate, RBC indices, and a reticulocyte count. These tests are all run using a whole blood sample from an anticoagulant tube, such as EDTA. (See Skill Box 4.1, Blood Collection Tubes, page 74.) The assessment of morphology and cell counts must be performed in a monolayer area of the slide. Thicker areas and the feathered edge should be evaluated for large structures, such as: platelet clumps, microfilaria, and mast cells. Cell inclusions are often confused with platelets and stain precipitate; their location (e.g., within the cell, surface of cell) should always be verified by focusing through the cell. Skill Box 4.6 / Complete Blood Count Procedure Definition/Uses Technique Normals Associated Conditions Packed Cell Volume (PCV, hematocrit, Hct) • Percentage of whole blood that is composed of RBCs • Fill a capillary tube 2/3–3/4 full with whole blood and plug 1 end with a clay sealant. • Centrifuge and read results as a percentage. • Record the color and transparency of the plasma. Canine • 37–55% Feline • 24–45% Plasma • Yellow and clear • ↑ Polycythemia, dehydration, stress, neonates • ↓ Anemia, overhydration, weanlings 4 Total Protein Concentrationa (TP) • Indicates oxygen transport capacity of the blood • Break a spun capillary tube above the buffy coat level and put the plasma onto the face of the refractometer. Canine • 5.4–7.6 g/dL Feline • 6.0–8.1 g/dL • ↑ Dehydration • ↓ Overhydration Hemoglobin Concentration (Hgb) • Indicates how well the blood is transporting oxygen • Follow manufacturer’s guidelines for machine’s use. • 1/3 of the PCV • ↑ (Falsely) lipemia, Heinz bodies • ↓ Hypochromic anemias RBC Count • Gives an accurate count of RBCs • Machine counters have shown to be more accurate than manual counting. • The main use of a RBC count is to calculate indices. 1. Prepare the sample (1 : 200 dilution) and hemacytometer (see Skill Box 4.7, page 108) 2. Find the grid at ×4, focus on the center square of the grid and then increase magnification to ×10, count the RBCs in the center square and each of the 4 corners using ×100. 3. Average the totals from grids of both stages and add 4 zeros. 4. Round to the nearest tenth place and put in scientific notation. Canine • 5.5–8.5 × 106/μL Feline • 5–10 × 106/μL • ↑ Polycythemia, dehydration • ↓ Anemia, overhydration WBC Count (TWBC) Gives an accurate count of total W.BCs 1. Prepare the sample (1 : 20 dilution) and hemacytometer. 2. Count the entire grid on ×10. 3. Average the totals from both grids. 4. (Averaged totals [AT] + 10% of AT) × 100 e.g., Grid #1 = 75 Grid #2 = 85 75 + 85 = 160/2 = 80 80 + 8 × 100 = 8,800 μL Canine • 6,000–16,000 μL Feline • 5,000–19,000 μL • ↑ Hemolysis, inflammation, hemorrhage, immune-mediated disease, infection, leukemia, necrosis, neoplasia, toxemia • ↓ Bone marrow disease, radiation, drug administration, retroviruses, myeloproliferative, lymphoproliferative diseases CHAPTER 4 / LABORATORY 105 Skill Box 4.6 / Complete Blood Count (Continued) Procedure Definition/Uses Technique Normals Associated Conditions Differential • Indicates the number of specific WBCs found circulating in the blood • The TWBC count should roughly equal the differential totals 1. Examine a prepared blood smear using ×100. 2. Count up 100 WBCs (neutrophils [N], bands [B], lymphocytes [L], monocytes [M], eosinophils [E], and basophils) and classify according to type. 3. See Skill Box 4.8 Calculating a Differential, page 108. Canine • N—3,600–11,500 • B— 0–300 • M—15–1,350 • L—1,000–4,800 • E—100–1,250 Feline • N—2,500–12,500 • B— 0–300 • M—0–850 • L—1,500–7,000 • E—0–1,500 • Variable dependent on type of cell(s) ↑ or ↓ Nucleated RBCs (nRBC) Color Plate 4.13 • Early release of immature RBCs • The corrected value should be calculated when >5 nRBCs are found and then used to calculate the differential. 1. While performing the differential, keep track of any nRBCs 2. Calculate a corrected TWBC count Corrected TWBC count = Observed TWBC count × 100 100 + nRBC • N/A • Anemia, lead poisoning, hemangiosarcoma Platelet Estimate • Indicates ability for adequate clotting 1. Examine a prepared blood smear using ×100 in which the RBCs are close but not touching, typically near the periphery of the slide. 2. Count 5 different fields and average. 3. Multiply by 15,000 and 18,000 to obtain a range. • When large areas of clumping are seen, assume adequate numbers of platelets. Canine • 200,000– 500,000 μL Feline • 300,000– 800,000 μL • ↑ Myeloproliferative disorder, megakaryocytic leukemia • ↓ B12, iron, or folic acid deficiency, drug toxicity, acute hemorrhage, radiation, viruses, uremia, aplastic anemia 4 Reticulocytes Not until a polychromatophilic erythrocyte is stained with Wright’s stain are they termed reticulocytes. These cells are large, anucleated cells containing RNA stained with a supravital stain (e.g., NMB). The RNA appears as blue intracellular granules. In canines, all reticulocytes are accounted for; however, in felines there are 2 types of reticulocytes and they should be counted and reported separately. Felines have aggregate reticulocytes and punctuate reticulocytes. Aggregate reticulocytes resemble canine reticulocytes and have distinct dark clumps of blue granules and would appear as polychromatophilic erythrocytes with Wright’s stain. Punctuate erythrocytes have individual scattered blue granules with no clumping and would appear as macrocytic mature red blood cells with Wright’s stain. When performing a reticulocyte count, only aggregate reticulocytes are counted as they are the best indicator of regenerative anemia. An ↑ in reticulocytes is expected 2–4 days after blood loss or destruction. A count >60,000 cells/μL indicates regenerative anemia and <60,000 cells/μL indicates a nonregenerative response. See Color Plates 4.13 and 4.17. 106 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.6 / Complete Blood Count (Continued) Procedure Definition/Uses Technique Normals Associated Conditions Reticulocyte Count • Immature RBCs • Used to evaluate the bone marrow’s response to anemia • Perform along with a CBC when severe anemia is present. • PCV values: • Canine: ≤30% • Feline: ≤20% 1. Mix together an equal part of whole blood with NMB, and agitate, and let it sit for 10 minutes. 2. Prepare a blood smear. 3. Examine under ×100 by counting 1,000 RBCs while separately keeping track of the number of reticulocytes. 4. Divide the reticulocyte number by 1,000 and convert to a percentage. 5. Calculate the corrected reticulocyte number. Corrected retic. % = Observed retic. % × PCV Normal mean PCV for species • <1% • ↑ Regenerative anemias RBC Indices Mean Corpuscular Volume (MCV) • Indicates the size or volume of RBCs • Classifies anemias as normocytic, macrocytic, or microcytic MCV (fl) = Canine • 60–77 fL Feline • 39–55 fL • ↑ Reticulocytosis, B12, folic acid deficiency • ↓ Iron deficiency Mean Corpuscular Hemoglobin (MCH) • The mean weight of Hgb in a RBC • Used as a lab check • ↑ MCH should see a ↑ MCV • ↓ MCH should see a ↓ MCV MCH (PG) = Canine • 19–24 PG Feline • 12–17 PG • ↑ Hemolysis • ↓ Iron deficiency Mean Corpuscular Hemoglobin Concentration (MCHC) • Indicates the average hemoglobin concentration in each RBC • Classifies anemias as hypochromic or normochromic MCHC (g dL) = Canine • 32–36 g/dL Feline • 30–36 g/dL ↑ Hemolysis, lipemia, Heinz bodies ↓ Iron deficiency PCV (%) × 10 RBC count × 106 μL Hgb (g dL) × 10 RBC count × 106 μL Hb (g dL) × 100 PCV (%) 4 a Score the capillary tube with the edge of slide just above the buffy coat to allow easy breaking. Using the unbroken end, tap onto the surface of the refractometer or blow air into the tube to expel the plasma. CHAPTER 4 / LABORATORY 107 Skill Box 4.7 / Hemacytometer Use 1. Prepare the WBC or RBC sample, following manufacturer’s directions. 2. Shake the sample just before use to redistribute the cells. 3. Fill the stylette by squeezing the bottle and expelling any air bubbles. 4 4. Place the hemacytometer on the table, and place the coverslip on top. 5. While stabilizing the hemacytometer, place the stylet in the indented portion and gently squeeze just until the stage is filled • Overfilling of the stage will result in multilevels of RBCs and give falsely ↑ values. 6. Load up the other indented area as previously described. Skill Box 4.8 / Calculating a Differential 1. Count up 100 WBCs and differentiate their type and record totals as %/μL. e.g., 45 neutrophils = 45%/μL = 0.45/μL 45 lymphocytes = 45%/μL = 0.45/μL 7 monocytes = 7%/μL = 0.07/μL 3 eosinophils = 3%/μL = 0.03/μL 0 basophils = 0 100 WBCs 2. Multiply each WBC type by the previously obtained TWBC count. e.g., TWBC count = 8,650 8,650 × 0.45 = 3893/μL neutrophils 8,650 × 0.45 = 3893/μL lymphocytes 8,650 × 0.07 = 606/μL monocytes 8,650 × 0.03 = 260/μL eosinophils 8,652/μL TWBC 3. The TWBC should roughly equal the TWBC count. e.g., TWBC (8,652) = TWBC count (8,650) 108 SECTION THREE: DIAGNOSTIC SKILLS Evaluation Once these tests have been performed, the blood is examined and evaluated on the basis of its morphology, inclusions, and presentation. While viewing in a monolayer area of the slide, the abnormality can be graded as the number per oil immersion field or the terms occasional and rare can be used. 1. Prepare a blood smear slide with stain or use the prepared slide from the differential. 2. Scan the slide, using low magnification. a. Platelet aggregation b. RBC rouleaux c. RBC agglutination 3. Examine the slide, using oil immersion magnification. a. RBC morphology i. Size ii. Shape iii. Color iv. Alterations b. WBC morphology i. Toxic changes ii. Nuclear degeneration iii. Cytoplasmic inclusions iv. Alterations c. Platelet i. Distribution ii. Alterations RBC Alterations and Morphology The normal morphology of a canine RBC is a large, biconcave disc (7.5 μm) of uniform size with central pallor. A normal feline RBC is a slightly smaller biconcave disk (5 μm) with only slight central pallor. When observing the prepared slide for RBC morphology, the cells should be evaluated for alterations in size, shape, color, and inclusions. Table 4.11 / RBC Alterations and Morphology (See figures in Color Plate 6–11) Alteration Definition Appearance Associated Conditions Agglutination • Immunoglobulin related cell bridging • Irregular, spherical aggregation or clumping of cells • IMHA, mismatch blood transfusion Rouleaux • ↑ Concentration of plasma proteins (e.g., fibrinogen, immunoglobulins) which results in linear aggregations of erythrocytes • Linear stacks or stack of coins • Multiple myeloma, lymphoproliferative disorders, inflammatory conditions • Slight amount is a normal findings in canines and felines Basophilic Stippling • Color Plate 4.13 • Residual RNA • Very small, dark-blue inclusions on the surface of the RBC • Anemia or lead poisoning Distemper • Color Plate 4.14 • Virus antigen or viral inclusion bodies (identification variable) • Variable sized round, oval, or irregular inclusions • Most often seen in polychromatophilic cells • Faint blue or magenta • Canine distemper virus Heinz Bodies • Color Plate 4.17 • Denatured hemoglobin caused by certain chemicals or oxidant drugs • Seen in up to 10% of normal feline RBCs • Single, light-colored, rounded protrusions within the RBC membrane • Best seen using new methylene blue stain • Lymphosarcoma, chronic renal failure, hyperthyroidism, diabetes mellitus, and oxidative toxins (e.g., onions, zinc, acetaminophen) Howell-Jolly Bodies • Color Plate 4.13 • Color Plate 4.15 • Color Plate 4.30 • Basophilic nuclear remnants seen in young RBCs • Dark blue to black spherical inclusions • Splenic disorders Hypochromasia • Color Plate 4.18 • ↓ Hemoglobin concentration • Can be confused with torocytes and immature polychromatophilic erythrocytes • ↑ Area of central pallor • Doughnut appearance • Iron deficiency • Often associated with anisocytosis in regenerative anemia Polychromasia • Color Plate 4.16 • Color Plate 4.17 • Color Plate 4.20 • Immature erythrocytes that have been released early • When polychromatic erythrocytes are stained with a supravital stain (e.g., NMB), they are termed reticulocytes. • Bluish or gray tint • Iron deficiency, regenerative anemia Microcytosis • ↓ Cell volume • RBCs smaller than normal • Iron deficiency Macrocytosis • ↑ Cell volume • Immature RBCs, reticulocytes • RBCs larger than normal • Regenerative anemia Arrangement 4 Inclusions Morphology, Color Morphology, Size CHAPTER 4 / LABORATORY 109 Table 4.11 / RBC Alterations and Morphology (Continued) Alteration Definition Appearance Associated Conditions Anisocytosis • Color Plate 4.30 • Variation in cell volume • Multiple possibilities (e.g., early cell release or increased cell division of RBCs) • The number of cells showing variation and the degree of variation from the largest to the smallest cells should be noted • Variation in cell size • Liver disease, spleen disorders, regenerative anemia Acanthocytes (spur cell) • Color Plate 4.20 • Caused by cholesterol concentration changes in the cell membrane • Irregularly spiculated • Severe liver disease, disseminated intravascular coagulation (DIC), hemangiosarcoma, hepatic lipidosis, lymphosarcoma, portosystemic shunts, and renal disease Blister Cells (prekeratocytes) • Color Plate 4.18 • Fusion of inner cell membranes • Blister or vacuole on the cell membrane • Iron deficiency Crenation • pH changes associated with slowdrying blood films • Notched or scalloped cell membrane • Artifact • Mostly seen in cats Dacrocytes • Deformed during maturation process • Can be confused with smeared RBCs during smear preparation • Tear shaped • Myelofibrosis Eccentrocytes (hemi-ghost cells) • Fusion of opposing oxidized cell membranes • Shifting of hemoglobin to 1 side, crescent shaped clear area outlined by a thin layer of membrane and lack of central pallor • Oxidative injury Echinocytes (burr cells) • Mechanism unknown, possibly calcium or adenosine triphosphate (ATP) changes in vivo • Evenly spaced, blunt to sharp projections of uniform shape and size • Scalloped edge • Renal disease, lymphosarcoma, doxorubicin toxicity, electrolyte depletion, and snake bites Keratocytes (bite or helmet cells) • Color Plate 4.18 • Blister cells (vacuolated cells) that enlarge and break open on 1 side of cell membrane • Spiculated cells with 2 or more projections • DIC, congestive heart failure, hemangiosarcoma, glomerulonephritis, and chronic doxorubicin toxicity Leptocytes (codocytes, target cells) • Color Plate 4.19 • Characterized by ↑ membrane and ↓ hemoglobin levels • Folded or resemble a target • Nonregenerative anemia 4 Morphology, Shape 110 SECTION THREE: DIAGNOSTIC SKILLS Table 4.11 / RBC Alterations and Morphology (Continued) Alteration Definition Appearance Associated Conditions Nucleated RBCs (metarubricytes, normoblasts) • Color Plate 4.1 • Color Plate 4.13 • Color Plate 4.16 • Early release of RBCs still maintaining its • Dark purple nucleus in a normal-size nucleus RBC • Regenerative anemia, splenic dysfunction, severe stress, hyperadrenocorticism, and corticosteroid treatment Poikilocytosis • Characteristic of ↑ RBC fragility • Variation in shape • Liver, kidney, spleen, and other vessel problems Schistocyte (fragments, helmet cells) • Color Plate 4.20 • Shearing of the RBC by intravascular trauma • Irregularly shaped fragments and sharp pointed projections • DIC, vascular neoplasms, severe burns, and iron deficiency Spherocyte • Color Plate 4.16 • ↓ Amount of cell membrane caused by partial phagocytosis by macrophages • Very difficult to distinguish in cats • Small, dark, round RBCs with little or no central pallor • Autoimmune hemolytic anemia (AIHA), transfusions, parasitic infections, zinc toxicity and snake venom toxicity Stomatocytes (mouth cells) • Multiple possibilities (e.g., leakage of sodium and potassium from the cell membrane) • Cup shaped • Split-like center opening • Liver disease, inherited disorders (e.g., Alaskan malamutes) Torocytes • Often confused with hypochromasia • Bowl-shaped or “punched-out cell” • Thick outer ring of hemoglobin with a sharply defined central clear area • Insignificant Babesia spp. • Color Plate 4.21 • Rare protozoan, tick-transmitted disease of dogs • Babesiosis (acute intravascular and extravascular • Large, teardrop- or ring-shaped hemolysis with hemoglobinuria) intercellular structures, often seen in pairs • Size: 1.5–3.0 μm Cytauxzoon felis • Color Plate 4.22 • Rare protozoan, tick-transmitted disease of cats • Small, irregular rings within RBCs, lymphocytes, or macrophages • Size: 0.5–2.0 μm • Hemolytic anemia, icterus, depression, and fever Mycoplasma haemocanis • Rare rickettsial disease affecting dogs • Chain of small cocci or rods that stretch across the surface of an RBC • Chains may branch • Size: 0.3–3.0 μm • Splenectomized or immunocompromised dogs Mycoplasma haemofelis Color Plate 4.15 • Common rickettsial disease of cats • Parasite is cyclic, and multiple slides may need to be evaluated for a diagnosis. • Parasite rapidly disappears with antibiotic treatment (e.g., tetracyclines). • Nonrefractile cocci, rod- or ring-like structures on the periphery of RBCs • Stain dark purple • Size: 0.5–1.0 μm • Immunocompromised cats, feline hemobartonellosis, or feline infectious anemia 4 Parasites CHAPTER 4 / LABORATORY 111 WBC Morphology The job of WBCs is to defend the body against foreign organisms, conducting their business in the tissues themselves. They are typically nonfunctional in the circulatory system. WBC morphology is significantly different between each type of cell. The frequency that they appear in the body is the order listed below. Table 4.12 / WBC Morphology (See figures in Color Plate 6–11) 4 WBC Definition Appearance (stained) Associated Conditions Neutrophils (Polys, Segs) • Color Plate • Color Plate • Color Plate • Color Plate • First line of defense against infection • Highly motile and phagocytic • Replaced in the body 2.5 times per day • Convoluted and segmented nucleus • Clear to light pink cytoplasm with diffuse granules • Coarse and clumped chromatin • ↑ Fear, exercise, stress, or inflammation • ↓ Severe infections, infectious agents causing decreased bone marrow production, chemical toxicity, and genetic disorders Bands • Color Plate 4.23 • Immature neutrophils • Hyposegmented nucleus with the constriction being <1/2 the width of the nucleus • Left shift is an ↑ in immature neutrophils • Nucleus is horseshoe shaped with large round ends • ↑ Inflammation, bacterial infection, and neoplasia Lymphocytes • Color Plate 4.24 • Color Plate 4.30 • Immunity and antibody production • Virus and tumor defense • Large, round, slightly indented, dark nucleus • Round cell with a small amount of blue cytoplasm • Large, pink cytoplasmic granules • ↑ Fear, excitement, chronic infections, leukemias, and lymphosarcoma • ↓ Corticosteroids, immunodeficiency diseases, loss of lymph, and impaired lymphopoiesis Monocytes • Color Plate 4.25 • Color Plate 4.26 • Highly phagocytic; digesting particulate and cellular debris • Antiviral and antitumor qualities • Become macrophages once in extravascular space • Large, elongated, lobulated, or indented nucleus • Bluish-gray cytoplasm • Large cell with lacy appearance caused by vacuoles • Pink dustlike inclusions • Diffuse nuclear chromatin • Blunt, agranular, light blue cytoplasmic pseudopods • ↑ Corticosteroids, stress, or severe infections and hemorrhages Eosinophils • Color Plate 4.27 • Color Plate 4.29 • Color Plate 4.30 • Ingest products of antibody/antigen reactions • Replaced once daily Canine • Clear cytoplasm with small to large, dull orange granules partially filling cell Feline • Pale cytoplasm with small, dull orange granules completely filling cell • ↑ IgE stimulation, parasitic infections and allergies • ↓ Corticosteroids Basophils • Color Plate 4.28 • Color Plate 4.29 • Their function is still unclear, but related to immunity • Rarely seen, possibly because of rapid degranulation Canine • Dark purple granules partially filling cell • Highly segmented nucleus • Gray-blue cytoplasmic vacuoles Feline • Violet cytoplasm with oval, nonstaining granules • Highly segmented nucleus • ↓ Hyperlipemia, chronic IgE stimulation and allergies 112 4.15 4.23 4.29 4.30 SECTION THREE: DIAGNOSTIC SKILLS Table 4.13 / WBC Alterations Neutrophil toxic change refers to morphologic changes due to altered bone marrow production. The neutrophils’ function is not altered, and they function normally. During an inflammatory response, the bone marrow releases neutrophils at an accelerated rate causing morphology changes such as Döhle bodies, cytoplasmic basophilia, and vacuolation. Reported by an index of 1+, 2+, etc. See Color Plates 4.32 and 4.33. Alteration Definition Appearance Associated Conditions Distemper • Virus • Variable sized round, oval, or irregular cytoplasmic and nuclear inclusions • Most often seen in polychromatophilic cells • Faint blue or magenta • Distemper virus Döhle Bodies • Color Plate 4.32 • Color Plate 4.33 • Retained rough endoplasmic reticulum • Seen with ↓ time in the marrow for maturation • Bluish–gray, angular cytoplasmic inclusions • Typically found at the periphery of the cell • Size: 0.5–2.0 μm • Severe toxemia, inflammation, and infection Chediak-Higashi Syndrome • Autosomal recessive inherited disorder • Fusion of preexisting granules • Persians are most commonly affected • 1–4 large (2.0 μm), fused lightly pink or eosinophilic cytoplasmic lysosomes in neutrophils • Band appearing eosinophils • Chediak-Higashi syndrome Cytoplasmic Basophilia • Color Plate 4.32 • Color Plate 4.33 • Persistent ribosomes • Varying degree of solid to patchy light blue to blue-purple cytoplasm • Severe toxemia, inflammation, and infection Cytoplasmic Vacuolation • Color Plate 4.33 • Disruption in bone marrow production, resulting in a loss of granule and membrane integrity • Foamy, bubble-like, nonstaining circles • Systemic toxicity Mucopolysaccharidoses • Deficiency of lysosomal enzymes needed for the degradation of glycoaminoglycans • Dark purple or magenta granules in neutrophils • Granules and vacuoles in lymphocytes • Mucopolysaccharidoses, lysosomal storage disorders Nuclear Hypersegmentation • Prolonged circulating life • ≥5 nuclear lobes • Aged neutrophils, prolonged storage of blood Nuclear Hyposegmentation • Early release of bands and immature neutrophils • Unsegmented nucleus • Steroid use, inflammatory response if intense/severe Pelger-Huët anomaly • Seen in heterozygotes for Pelger-Huët anomaly • Hyposegmented mature neutrophils with a coarse chromatin pattern without inflammation present • Pelger-Huët anomaly Pyknosis • Result of improper anticoagulant • Effect on nucleus • Condensed, lysed or damaged nucleus • Insignificant Inclusions 4 Morphology CHAPTER 4 / LABORATORY 113 Table 4.13 / WBC Alterations (Continued) 4 Alteration Definition Appearance Associated Conditions Reactive Lymphocyte (Immunocytes) • Color Plate 4.31 • Immune-stimulated T- and B-cells • Cytoplasm and basophilia and a larger, more convoluted nucleus • Antigenic stimulation (e.g., canine ehrlichiosis) Vacuolated Lymphocytes • Accumulation of storage products (e.g., proteins, carbohydrates, lipids) • Cytoplasmic vacuoles • Acquired lysosomal storage disorder, prolonged storage of blood Cytauxzoon felis • Rare protozoan, tick-transmitted disease of cats • Small, irregular rings within RBCs, lymphocytes, or macrophages • Size: 0.5–2.0 μm • Hemolytic anemia, icterus, depression, and fever Ehrlichia canis • Rickettsia, tick-transmitted disease of dogs • Large granular lymphocytes • ↑ Cytoplasm and cell size • Variable sized pink cytoplasmic granules typically clustered next to the nucleus (difficult to find) • Ehrlichiosis Parasites Table 4.14 / WBC Left Shift An increased number of circulating immature neutrophils indicates a left shift. Bands are the most common immature neutrophil identified; however, metamyelocytes and myelocytes can also be seen in more severe cases. Appearance Left Shift • ↑ Immature neutrophils • >300 μL/blood Regenerative Left Shift • • • • Degenerative Left Shift • Neutropenia or slight neutrophilia • Mature cells < immature cells • Leukopenia Transitional Left Shift • Moderate to marked neutrophilia • Mature cells < immature cells Right Shift • Nuclear hypersegmentation Stress Leukogram (Corticosteroid Leukogram) • • • • 114 SECTION THREE: DIAGNOSTIC SKILLS Neutrophilia Mature cells > immature cells Lymphopenia Monocytosis Mature neutrophilia Lymphopenia Eosinopenia +/− Monocytosis Platelet Morphology 1. Venipuncture should be atraumatic while using the largest vein possible. Platelets absorb and carry plasma factors needed to form fibrin to facilitate hemostasis. These thrombocytes vary in size and shape and are nonnucleated with pale blue to lavender granules. They are often seen in clumps at the periphery or feathered edge of a prepared slide. See color plates 4.15, 4.17, and 4.30. 2. Drawn blood should come into contact with the tube additive as soon as possible. 3. The following tubes will give invalid results and should not be used: LTT, GRNTT, SST. 4. Spun samples that are hemolyzed or have visible clots should be redrawn. 4 Table 4.15 / Platelet Alterations Alteration Definition Appearance Associated Conditions Megathrombocytes (Stress platelets, shift platelets, or giant platelets) • Color Plate 4.31 • Seen in felines, contributes to not being able to use an electronic counter • Larger than an RBC • Bone marrow disorders, myelo proliferative disorders Table 4.16 / Coagulation Screening Specific coagulation tests are chosen based on which factors they are able to evaluate. Coagulation Factor ACT APTT PIVKA PT TT Extrinsic Pathway Coagulation Tests Hemostasis is the normal arrest of bleeding and abnormalities of this process can be seen as excessive bleeding (hemorrhage) or excessive hemostasis (intravascular thrombosis). The coagulation process is a sequence of events divided into 3 pathways; intrinsic, extrinsic, and common. Each pathway consists of several coagulation factors that contribute to the entire hemostasis process. A deficiency or abnormality in any 1 or combination of factors can alter the entire process leading to a coagulopathy. Coagulation tests are performed in patients exhibiting signs of questionable clotting abilities. They are able to distinguish between a coagulation problem and a patient with damaged or diseased blood vessels. These tests or a combination of tests can aid in a diagnosis (e.g., von Willebrand disease, DIC) or as monitoring to a hereditary condition or current condition. Blood drawn for coagulation tests must be collected and handled following very specific guidelines to obtain proper results. Activation of the clotting pathway will give erroneous results. Some tips to remember are: III X VII X X Intrinsic Pathway VIII X X IX X X XI X X XII X X I (Fibrinogn) X X II (Prothrombin) X X V X X X X X X Common Pathway X X X X X X X CHAPTER 4 / LABORATORY 115 Skill Box 4.9 / Coagulation Tests Test Definition Procedure Normals Activated Clotting Time (ACT) • Test of intrinsic clotting mechanism • Less sensitive than APTT • Clot formation may be inhibited by administration of salicylates, NSAIDs, anticoagulants, antibiotics, barbiturates. 1. Warm syringe and tube containing diatomaceous earth to 98° F (37° C).a 2. Inject 2 mL freshly drawn whole blood into tube and invert 5 times to mix. 3. Begin the clock with the injection of blood into the tube and incubate in a warm water bath for 1 minute. 4. Observe at 5-second intervals for the first sign of clotting. • Place the tube back in incubation between each 5-second check. Canine • 60–120 seconds Feline • 60–75 seconds • May be slightly prolonged with thrombocytopenia Buccal Mucosal Bleeding Time (BMBT) • Making a standard wound and noting the time to the cessation of bleeding. • Some NSAIDs, analgesics and sedatives may alter the results. • Evaluates platelet dysfunction and severe von Willebrand disease 1. Make a deep puncture at a site with no hair (e.g., buccal, gingiva, nose). 2. Begin timing when blood appears. 3. Remove the blood with filter paper at 30second intervals. 4. Stop timing when there is no more blood. • Do not touch the skin with the filter paper. Canine/Feline • 1–5 minutes Toenail Bleeding Time (TBT) • Evaluates platelet dysfunction, severe von Willebrand disease, hemorrhagic phase of DIC, and coagulation factor deficiencies 1. Clip a toenail back past the quick to cause bleeding. 2. Keeping the animal undisturbed, monitor for the bleeding to cease. Canine/Feline • <5 minutes Platelet Estimate • Estimation of platelet number 1. Examine a prepared blood smear, using ×100 on a place where the RBCs are close but not touching near the periphery. 2. Examine at least 5 fields to ensure accurate results. Canine • 8–29/×100 field Feline • 10–29/×100 field Clot Retraction Test • Evaluation of platelet number and function and intrinsic and extrinsic pathways. 1. Draw a blood sample into a plain sterile tube and incubate at 37° C. 2. Exam the tube at 60 minutes where a clot should be evident. 3. Examine the tube at 4 hours to find a retracted clot. 4. Examine the tube at 24 hours to find a markedly compact clot. • 60 minutes: clot evident • 4 hours: clot retracted • 24 hours: clot markedly compact Quick Assessment Tests 4 116 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.9 / Coagulation Tests (Continued) Test Definition Procedure Normals • Test of intrinsic clotting mechanism and common coagulation pathways • Measure the time in seconds for fibrin clot formation. • Proper dilution is crucial to the accuracy of this test. 1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube. Canine • 8–13 seconds Feline • 13–30 seconds Fibrin Split Product (FSP) or Fibrin Degradation Product (FDP) • Measures the presence of products that result from the action of plasmin on fibrin and fibrinogen • Proper dilution is crucial to the accuracy of this test. • Aids in DIC diagnosis 1. Draw a fresh blood sample to fill an FDP tube (2 mL). 2. Gently invert sample 6–10 times. • Clot formation should occur shortly after blood draw. Canine/Feline • <10 mg/mL Fibrinogen • Quantitative measure of plasma fibrinogen 1. Draw a fresh blood sample to fill an LTT. 2. Gently invert sample 6–10 times to activate anticoagulant. Canine • 100–250 mg/dL Feline • 100–350 mg/dL Protein C Activity Assay • Measures the percentage of protein C • Aids in the diagnosis of thrombotic disorders and hepatic disease 1. Draw a fresh blood sample, using a needle (vacutainer preferred), into a 2-mL BTT, or use a syringe containing citrate (1 part citrate to 9 parts blood). • Do not use a dry syringe and then transfer blood into a BTT. 2. Centrifuge blood and gently pipette off plasma into a plastic container and freeze. Canine • 75–135% Feline • 65–120% Protein Induced by Vitamin K Antagonism/Absence (PIVKA Test) • Detects any coagulation factor deficiency of extrinsic clotting mechanism and common coagulation pathways 1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Centrifuge sample, pipette off plasma, and freeze in a plastic tube. Canine • <25 seconds Prothrombin Time (PT) • Test of extrinsic clotting mechanism and common coagulation pathways • Measures the time in seconds for fibrin clot formation • Proper dilution is crucial to the accuracy of this test. • Used for vitamin K antagonist poisons 1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube. Canine • 5–8 seconds Feline • 8–11 seconds Definitive Tests Activated Partial Thromboplastin Time (APTT) CHAPTER 4 / LABORATORY 4 117 Skill Box 4.9 / Coagulation Tests (Continued) Test Definition Procedure Normals Thrombin Time (TT) • Test abnormalities of the conversion of fibrinogen to fibrin • Measures the amount of time for a fibrin clot formation in citrated plasma after the addition of thrombin • Normal values with rodenticide poisonings 1. Draw a fresh blood sample to fill a BTT. 2. Gently invert sample 6–10 times to activate anticoagulant. 3. Refrigerate if testing is <24 hours or centrifuge sample, pipette off plasma, and freeze in a plastic tube. Canine/Feline • 10–12 seconds von Willebrand Factor Assay (vWF) • Measurement of vWF antigen • Proper dilution is crucial to the accuracy of this test. • Do not test during pregnancy, estrus, lactation. • Draw sample before beginning therapy (e.g., plasma, cryoprecipitate) or wait 48 hours post therapy. 1. Draw a fresh blood sample, using a vacutainer needle, into a 2-mL BTT, or use a syringe containing citrate (1 part citrate to 9 parts blood). • Do not use a dry syringe and then transfer blood into a BTT. 2. Centrifuge blood and gently pipette off plasma into a plastic container. • Within 30 minutes, the sample should be centrifuged, transferred into a plastic tube, and frozen. • Variable, dependent on bleeding time and vWF antigen percentage 4 a 118 Place the tube against your body (e.g., armpit or hand) for easy incubation. SECTION THREE: DIAGNOSTIC SKILLS Blood Transfusions Skill Box 4.10 / Crossmatching Crossmatching determines the compatibility between donor and recipient blood by washing erythrocytes and incubating them with plasma. This procedure will identify incompatibilities that are not identified on blood typing since blood typing only identifies the most common types. However, crossmatching will not pick up low titer antibodies or WBC antigens and not identify incompatibilities to DEA 1 blood types unless previous sensitization (e.g., prior transfusion history) has occurred. Crossmatching is not a substitute for blood typing; both procedures must be performed on every patient (especially feline). Crossmatch Use Procedure Results Major • Comparing donor erythrocytes to recipient serum • Checking for preformed antibodies in the recipient serum against RBCs from the donor Positive • Any hemolysis or agglutination voids any chance of transfusions with this donor. • Agglutination appears as grape-like clusters. Minor • Comparing recipient erythrocytes to donor serum • Checking for preformed antibodies in the donor serum that could hemolyse recipient RBCs 1. Collect 1 mL of donor blood and 1 mL of recipient blood and place them each in a separate purple top tube (EDTA) or green top tube (heparin). Spin each tube for 10 minutes to separate plasma. Remove and save the plasma from each in clean glass or plastic tubes. 2. Wash the RBCs by taking 0.2 mL of RBCs and diluting in 5 mL of 0.9% saline. Spin this for 1 minute, remove the supernatant, and repeat the procedure 2 more times with the pelleted RBCs. 3. Prepare 3 tubes by labeling them as Major, Minor, and Recipient Control. To each tube, add 2 drops of plasma and 2 drops of blood to each as follows: • Major crossmatch: recipient plasma + donor cells • Minor crossmatch: donor plasma + recipient cells • Recipient control: recipient plasma + recipient cells 4. Let the tubes sit at room temperature for 15–30 minutes and then centrifuge for 15 seconds. 5. Check the supernatant for hemolysis and then gently resuspend the pellet by tapping the tube to check for RBC agglutination. Agglutination or hemolysis of the control indicates immune-mediated disease. 6. If agglutination is not observed, transfer a small amount to a slide and examine for microscopic agglutination. 4 Positive • Severe hemolysis or agglutination voids transfusion with this donor. • If the donated plasma with slight hemolysis or agglutination is to contribute substantially to the recipient’s plasma volume, the plasma should be removed from the whole blood and packed RBCs should be reconstituted with sterile saline. CHAPTER 4 / LABORATORY 119 Skill Box 4.11 / Blood Typing Procedure Results Canine Follow the manufacturer’s directions • Add the diluent to each well to rehydrate the lyophilized material. Add 1 drop of the controls and purple top blood sample to appropriate wells. Mix each well and then rock the test card. Prop the card up at a 10° angle to allow the blood to fall to the bottom of the well. Note the wells where gross agglutination has occurred. • If the patient shows gross agglutination in the well marked “Patient Test” and there is no autoagglutination, the patient is DEA 1.1 positive. If no agglutination is visible in the well marked “Patient Test,” the patient is DEA 1.1 negative. • If the patient is very anemic, the pattern of agglutination may be in the form of discrete, small aggregations, each like the head of a large pin, rather than gross agglutination. • Any fine, granular appearance developing after 2 minutes should be disregarded in determining results. Feline Follow the manufacturer’s directions • Add the diluent to each well to rehydrate the lyophilized material. Add 1 drop of the controls and purple top blood sample to appropriate wells. Mix each well and then rock the test card. Prop the card up at a 10% angle to allow the blood to fall to the bottom of the well. Note the wells where gross agglutination has occurred. • If the assay was run correctly, visible agglutination should have occurred in at least 1 of the wells marked “Patient Test.” • If the patient sample shows agglutination in the well marked “Type A,” the cat tested has blood group A. If the patient sample shows agglutination in the well marked “Type B,” the cat tested has blood group B. If the patient sample shows agglutination in both patient wells, the cat tested has blood group AB. • If the patient is very anemic, the pattern of agglutination may be in the form of discrete, small aggregations, each like the head of a large pin, rather than gross agglutination. • Any fine, granular appearance developing after 2 minutes should be disregarded in determining results. 4 IMMUNOLOGY AND SEROLOGY TESTS Table 4.17 / Immunology and Serology Tests Immunology and serology tests are specialized laboratory tests used to obtain information regarding the functioning status of the immune system and the diagnostic identification of antibodies in the serum, respectively. They can be valuable tools in the diagnostics of infectious diseases and autoimmune diseases when used in conjunction with other diagnostics. Due to the complexity of these tests, reference laboratories are required for their processing. Each laboratory has varying requirements for sample submission and should be referred to for more information. See Blood Chemistries for Blood Collection, Handling, Storage, and Transport Tips, page 74. Test Technique Associated Conditions Coombs’ Test (Direct Antiglobulin Test) A species-specific Coombs’ reagent is added to the blood. RBCs that are coated with antibodies will cause agglutination with the added reagent. • Autoimmune hemolytic anemia (AIHA) Enzyme-Linked Immunosorbent Assay (ELISA) A tray with antibody coated wells is filled with the sample. If any antigen is present, it will bind with the antibody in the coated wells. A second enzyme-tagged antibody is added and binds to the antibody–antigen complex. A substrate that reacts with the enzyme is then added and results in a color change if antigen is present. The color change is proportional to the amount of antigen in the sample. The antigen may be actual viral/bacterial material (e.g., FeLV) or the host’s antibody vs. the pathogen (e.g., FIV). • Heartworm, canine parvovirus, FIV, FIP, FeLV, toxoplasmosis, progesterone, atopy, nonregenerative anemia, allergies, and Lyme disease 120 SECTION THREE: DIAGNOSTIC SKILLS Table 4.17 / Immunology and Serology Tests (Continued) Test Technique Associated Conditions Immunodiffusion Viral antigen and an antibody are placed into separate wells in agar. They diffuse through the agar and form a visible band of precipitation if any viral antigen is present. • Viral and fungal pathogens Immunofluorescence Assay (IFA) Direct IFA An antibody for a specific virus is tagged with a fluorescent dye and combined with the sample. If the specific virus is present, the antibody will bind and appear fluorescent during microscopic examination. • Ehrlichiosis and Rocky Mountain spotted fever Indirect IFA An antiviral antibody (immunoglobulin) that was produced in an animal (e.g., rabbit) and a fluorescent tagged antirabbit immunoglobulin are combined with a sample. The second antibody combines with the first antibody, which binds to any viral antigen present in the sample. The antibody-antibody-antigen complex will fluoresce during microscopic examination. • Cryptosporidium, FIV, Giardia, and systemic lupus erythematosus Immunoperoxidase Test (PAP) A specific antibody is bound to the cell or tissue sample. The detection of specific antibody can be done through 3 different methods, all consisting of tagging the antibody and eventually generating a colored product. • CDV, distemper, FeLV, FIP, Neospora, Toxoplasma Intradermal Tests Allergenic extracts are injected intradermal and observed for changes. A wheal formation indicates the presence of antibodies and an allergic reaction. • Allergies; flea allergy Latex Agglutination Small, spherical antibody (or antigen)–coated latex particles are suspended in water. The sample is added, and any antibody–antigen complex will undergo agglutination. The water will be milky or contain clumps of latex particles. • Canine rheumatoid factor, brucellosis, and DIC antigen complexes that form will cause agglutination. Polymerase Chain Reaction (PCR) A specific nucleic acid primer reacts with a portion of the genome from the microorganism in question. The combination is amplified to produce many fragments of the DNA sequence. Electrophoresis is then used to detect the combination and to measure its size and migration pattern. • Often used to confirm results of other tests • Herpesvirus, FeLV, FIV, coronavirus, Bartonella, Ehrlichia, etc. Radioimmunoassay An antibody for a specific virus or antigen is tagged with a radioactive element (e.g., iodine) and combined with the sample. A gamma counter is used to identify the antibody–antigen complex. • Thyroid diseases Serum Antinuclear Antibody (ANA) Serum is serially diluted and added to a prepared slide with 10 areas of monolayer cell lines. If antinuclear antibodies are present, they bind to the nucleus and can be detected through immunofluorescence or immunoperoxidase techniques. • Glomerulonephritis, immune mediated thrombocytopenia, polyarthritis, polymyositis, systemic lupus erythematosus CHAPTER 4 / LABORATORY 4 121 Table 4.17 / Immunology and Serology Tests (Continued) Test Technique Associated Conditions Serum Rheumatoid Factor Latex beads are coated with an antigen which will bind to the rheumatoid factor antibody found in serum or synovial fluid of affected animals • Polyarthritis of erosive/lytic type Western Blot (Immunoblot) Antigens are separated by electrophoresis and blotted to nitrocellulose sheets. The sheets are incubated with labeled antibodies and then observed for bound antibodies by using enzymatic or radioactive methods. • Used to confirm ELISA results • FIV 4 MICROBIOLOGY A small animal laboratory should only be responsible for presumptive identification of bacteria. Further tests for a definitive diagnosis should be sent to a referral laboratory, where they have access to a greater number of techniques and equipment. Skill Box 4.12 outlines basic guidelines for collection of the sample followed through to the preliminary evaluation and interpretation of bacterial growth. Books dedicated to the subject of microbiology should be consulted for further discussion of alternative tests and techniques. 122 SECTION THREE: DIAGNOSTIC SKILLS Microbiology Collection, Handling, Storage, and Transport Tips Collection • Collect sample aseptically. • Collect an adequate amount of the samples to allow for complete examination. • Samples should be attained before starting antibiotic therapy. Skill Box 4.12 / Collection Techniques Site Collection Abortion • Entire fetus or multiple specimens from a range of body parts should be obtained as soon as possible after the animal has died. Abscess/Wound • Unruptured: sterile syringe with wide-bore needle • Ruptured: swab near the edge of the wound and take scrapings from the inside wall of the abscess. Anaerobic bacteria • Sterile syringe with fine-gauge needle • Expel all air out of syringe before obtaining sample. Blood • 5–10 mL of blood from at least 2 different sites and immediately placed in separate blood culture bottles. Collect multiple samples throughout the day. Ear • Swabs of both ears canals and middle ear if needed Eye • Corneal scrapings, swab of the conjunctival sac, or swab of lacrimal secretions Fecal • 1 g freshly voided or rectal examination–obtained feces • Clean anus before collection to avoid contamination with anal skin microflora. Genital • Swab of vulvar mucosa Leptospirosis • 20 mL of midstream urine Urine • 5 mL urine via a catheter or cystocentesis 4 Note: See Cytology, Skill Box 4.3, page 88, and Urinalysis, page 150, and Skill Box 12.8, page 434, and Skill Box 12.10, page 435, sections for specimen collection techniques. Handling • Samples should be handled carefully to avoid human contamination. • Separate multiple samples to avoid cross contamination. • Maintain a clean environment in which the laboratory tests are run. • Wood-shafted and cotton-tipped swabs should not be used with samples suspected of Chlamydia. Storage • Swabbed samples need to be placed in a transport media if they are not immediately inoculated. • Agar plates must be stored inverted to prevent condensation buildup on the surface of the agar. • Sample should be clearly marked with patient’s name, number, origin of the sample, time of collection and whether it was refrigerated. CHAPTER 4 / LABORATORY 123 Table 4.18 / Specimen Storage 4 Test Specimen Storage Acid-Fast Stain Tissue • Red top tube Slides • Slide holder Anaerobic Bacteria Fluid • Sterile syringe with fine-gauge needle in a rubber stopper secured with tape • Culturette swab Blood Blood (5–10 mL) • Blood culture bottle (commercially prepared) Chlamydia Tissue or dacron swab • Chlamydia transport media Culture and Sensitivity (bacterial) Swab • Culturette swab or Transwab Fluid • Red top tube Tissue • Enteric transport media or red top tube Fecal Culture Feces • • • • Fungal culture Hair, scrapings or swab (yeast only) • Red top tube • Culturette swab • Transwab Fluid • Screw-cap tube Slides • Slide holder Swab • Culturette swab • Transwab Fluid or tissue • Red top tube Swab • Culturette swab • Transwab Fluid • Red top tube Tissue • Enteric transport medium • Red top tube Plate with growth • Culture plate KOH Preparation Scrapings or clipped hair or nails • Red top tube Mycoplasma Fluid and tissue • Mycoplasma transport media • Culturette swab • Note: Mycoplasma may adhere to swabs, giving negative results Sensitivity Only Plate with growth • Culture plate Urine Fluid • Culture needs to be set up within 2 hours to avoid overgrowth of insignificant bacteria or refrigerated for no longer than 18–24 hours Gram Stain Identification Only 124 SECTION THREE: DIAGNOSTIC SKILLS Culturette swab Enteric transport media Red top tube Clean, dry container Transport • Tape the lids and caps of inoculated tubes and plates before shipment. • Empty the water that has accumulated on the lid to avoid it dropping onto the agar plate and mixing the colonies of bacteria. • Tissue submitted for fungal cultures should be frozen and marked “Caution” because of its zoonotic potential. 4 Table 4.19 / Most Commonly Used Culture Media Numerous types of culture media are available; however, most veterinary clinics use only a few. The more extensive cultures are sent to reference laboratories for growth and interpretation. a Medium Preparation Uses Interpretations Blood Agar • Trypticase soy agar • Sheep’s blood • Enriched media that supports the growth of most bacteria • Observe for growth, rate of growth, morphology, and hemolytic patterns: • Gamma: no lysis or color change • Alpha: incomplete lysis of RBCs, greenish halo around the bacterial growth • Beta: lysis of RBCs, clear halo around bacterial growth Brain–Heart Infusion Broth • Calf’s brain • Beef’s heart • Dextrose • Enrichment media to increase the number of organisms • Subcultures are made onto agar plates after incubation of 24 hours Dermatophyte Test Medium • • • • • Detection of Microsporum canis and Microsporum gypseum • Observable growth with a simultaneous red color change in 14–21 days MacConkey Agar • Crystal violet • Bile acids • pH indicator • Selects for gram-negative and Enterobacteriaceae • Helps differentiate bacteria • Pink to red colonies: lactose fermenters • Colorless to light yellow colonies: nonlactose fermenters Thioglycollate Brotha • Thioglycollic acid • Yeast extract • Dextrose • Supports growth of anaerobic and facultative anaerobic bacteria • Turbid or streaks if turbidity is not disturbed Sabouraud’s dextrose agar Antibiotic Cycloheximide Phenol red Thioglycollate broth should not be used as the only source of collection media. CHAPTER 4 / LABORATORY 125 Skill Box 4.13 / Culture Media Inoculation and Incubation General Points for Proper Technique • Keep culture plates closed unless inoculating or transferring specimens. • Do not set down the tube cap of medium to avoid contamination. • Flame the neck of the tube before and after transferring specimens. 4 b. Stab only: stab the wire through the agar and then slowly withdraw it along the same stab path. c. Butt and Slant: combine the above 2 methods, starting with the stab method and finishing with the slant method. 4. Remove the wire and reflame. • When flaming the inoculation loop or wire, place the end closest to the handle in the hottest portion of the flame, the blue portion, and then move toward the loop to prevent splattering. Broth Inoculation • When transferring the sample to the agar, use a gentle touch to avoid tearing the surface of the agar. 2. Dip the wire into the specimen to be cultured. Plate Inoculation 1. Mentally divide the agar plate into 4 quadrants. 2. Flame and cool the inoculation loop. 1. Flame and cool the inoculation loop or wire. 3. Insert the loop or wire into the broth just below the surface and touch the side of the tube. 4. Remove the loop or wire and reflame. Tip: Work with 2 inoculation loops; one can be cooling while the other is in use. 3. Dip the loop into the specimen to be cultured. 4. Streak the specimen in quadrant A. Incubation of Cultures 5. Repeat steps 2–4 while slightly overlapping the previous quadrant and then moving around to each quadrant. Be sure to only overlap the previous quadrant’s streaks 1–2 times to prevent excessive numbers of bacteria in 1 area. Quadrant D is expected to grow isolated colonies. • Maintain incubator temperature at 98.6° F and humidity of 70%. 7. Remove the loop and reflame. Slant Inoculation 1. Flame and cool the inoculation wire. 2. Dip the wire into the specimen to be cultured. 3. Types of slant inoculations: a. Slant only: make a “S” shape across the slant with the tip of the inoculation wire. 126 SECTION THREE: DIAGNOSTIC SKILLS • Plates should be placed upside down to prevent the accumulation of condensation on the surface of the agar plate. • Tube media screw caps should be left loose during incubation. • Cultures should be incubated for 48 hours and checked after 24 hours. • To ↑ the level of carbon dioxide, place the plates upside down in a glass jar with a candle on top. Light the candle and place a tightly fitting lid on top. Allow the candle to burn itself out, which will decrease the amount of oxygen and increase the amount of carbon dioxide. This does not create an anaerobic environment. • Place a bowl of water in the bottom of the incubator to maintain a high humidity. Evaluation of Culture Growth c. Acid-fast stain d. Negative stain 1. Identify the source of the sample. 5. Differentiation tests 2. Growth Significant Not Significant • Only 1–2 types of bacterial growth • >3 Types of scant bacterial growth • Circular colonies with clear edges, • Large, irregular, and granular smooth, convex, or rounded colonies and spreading edges • Opaque to gray • Heavily pigmented 3. Changes to the media a. Hemolytic pattern b. Color change c. Odor 4. Microscopic evaluation a. Catalase test i. Differentiates between catalase-positive (e.g., staphylococci) and catalase-negative (e.g., streptococci, enterococci) bacteria ii. Positive test: formation of bubbles b. Oxidase test i. Differentiates between oxidase-positive (e.g., Bordatella bronchiseptica, Pseudomonas aeruginosa) and oxidase-negative (e.g., enterobacter species, escherichia species) bacteria ii. Positive test: purple color change c. Indole test i. Differentiates between indole-positive (e.g., Escherichia coli, Proteus vulgaris) and indole-negative (e.g., Streptococcus pyogenes, Salmonella typhimurium) bacteria ii. Positive test: red color on the surface of the tube a. Simple stain b. Gram stain Skill Box 4.14 / Staining Solutions and Procedures The first step to identification of microbiology slides is to properly prepare the slide. All staining of slides should be done on an air-dried heat-fixed slide. To heat-fix a slide, make several rapid passes of the slide over a flame source (e.g., matches, lighter, or Bunsen burner). Once the slide has been immersed in staining solution, it should be agitated to allow fresh stain to remain in contact with its surface. Staining Technique Uses Preparation Procedure Interpretation Diff-Quik (modified Wright’s stain) General cytology and demonstration of bacteria • Fixative: methanol, triarylmethane dye • Eosinophilic: xanthene dye • Basophilic: thiazine dye mixture 1. Dip the prepared slide 5 times slowly in methanol fixative. 2. Repeat above with eosinophilic stain and basophilic stain. 3. Rinse with water. 4. Air dry. • Clear differentiation of cellular morphology • Staining ranges from pale pink to dark purple. Giemsa Stain Detection of spirochetes and rickettsiae • Fixative: methanol • Giemsa powder • Glycerol 1. Fix the prepared slide in absolute methanol for 3–5 minutes and air dry. 2. Place the slide in diluted stain; 0–30 minutes. 3. Rinse with water and air dry. • Purplish-blue stained bacteria Differential Stains CHAPTER 4 / LABORATORY 127 4 Skill Box 4.14 / Staining Solutions and Procedures (Continued) Staining Technique Uses Preparation Procedure Interpretation Gram Stain Distinguish between gram-positive and gram-negative bacteria based on their cell wall structure • Primary stain: crystal violet • Mordant: Gram’s iodine • Decolorizer: alcohol • Counterstain: dilute carbol fuchsin or safranin 1. Flood the prepared slide with crystal violet; 30–60 seconds. 2. Rinse with water for 5 seconds. 3. Flood the slide with ram’s iodine; 30–60 seconds. 4. Rinse with water for 5 seconds. 5. Decolorize until the purple color is gone; ∼10 seconds. 6. Rinse with water for 5 seconds. 7. Flood the slide with dilute carbol fuchsin; 30–60 seconds. 8. Rinse with water for 5 seconds. 9. Air dry or blot between towels. • Purple-stained bacteria are gram-positive. • Red-stained bacteria are gram-negative. Lactophenol cotton blue Detection of fungi • Lactophenol cotton blue Same as simple stain • Visualization of hyphae, septae, and structure of spores Ziehl/Neelson or Acid-Fast Stain Detection of Mycobacterium spp. and Nocardia • Carbol fuchsin • Acid alcohol • Methylene blue 1. Flood the prepared slide with carbol fuchsin and heat over a flame until it steams and then let it sit; 5 minutes. 2. Rinse with water. 3. Decolorize with acid alcohol until the red color is gone; 1–2 minutes. 4. Rinse with water. 5. Counterstain with methylene blue; 2 minutes. 6. Rinse with water and dry over low heat. • Acid-fast bacteria stain red. • Non–acid-fast bacteria stain blue. Modified Ziehl/ Neelson Stain With Brilliant Green Detection of Mycobacterium spp. and Nocardia • Carbol fuchsin • Acid alcohol • Brilliant green 1. Flood the prepared slide with carbol fuchsin; 3 minutes then heat. 2. Rinse with water. 3. Decolorize with acid-alcohol; 3 minutes. 4. Rinse with water. 5. Counterstain with brilliant green; 3 minutes. 6. Rinse and dry. • Acid-fast bacteria stain red. • Non–acid-fast bacteria stain green. Modified Ziehl/ Neelson Stain With Methylene Blue Detection of Brucella, Nocardia, and Chlamydia • Carbol fuchsin • Acetic acid • 0.5% Methylene blue 1. Flood the prepared slide with dilute carbol fuchsin; 10 minutes. 2. Rinse with water. 3. Decolorize with acetic acid; 20–30 seconds. 4. Rinse with water. 5. Counterstain with methylene blue; 2 minutes. 6. Rinse and dry. • Brucella and Chlamydia stain bright red and in clumps. 4 128 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.14 / Staining Solutions and Procedures (Continued) Staining Technique Uses Preparation Procedure Interpretation Detection of capsules and difficult to stain bacteria (e.g., spirilli) A negatively charged chromogen stain • India ink • Nigrosin 1. Prepare an air-dried slide. 2. Apply 1–2 drops of stain to prepared slide. 3. Apply coverslip and examine as a wet mount. • Capsules appear clear and unstained, surrounded by dark particles. Demonstration of bacteria and general morphology and shape arrangement A positively charge chromogen stain • Carbol fuschin • Crystal violet • Methylene blue • New methylene blue • Safranin Technique #1 1. Place 1 drop on the coverslip and apply to prepared slide. 2. Place a paper towel over the coverslip and apply gentle pressure to absorb excess stain. Technique #2 1. Place 1 drop of stain next to the coverslip on a prepared slide and allow the stain to leak under the coverslip. 2. Place a paper towel over the coverslip and apply gentle pressure to absorb excess stain. Simple Stains Negative Staining Simple Stain 4 • Visualization of cell shape and arrangement • Reticulocytes, Heinz bodies, urine sediments, and oily preparations (e.g., suspected lipomas using new methylene blue) Note: Stains should be periodically filtered, using filter paper to remove any precipitate that may have formed. Note: Rinse slides on the reverse side to avoid disturbing the sample. Note: If a slide is overstained with Diff-Quik, place the slide in methanol for several minutes to destain and then restain. If the slide is understained with Diff-Quik, restain the slide with the appropriate stain color. CHAPTER 4 / LABORATORY 129 Skill Box 4.15 / Staining Problems To avoid staining problems, use fresh clean stains and slides, do not touch the surface of the slide, and immediately stain slides after air-drying. Problem Solution Excessive Staining • • • • ↓ Staining time Rinse adequately between stains and after staining. Prepare a thinner sample on the slide. Allow slide to dry before applying coverslip. Weak Staining • • • • ↑ Staining time Change stains. Stain slides sooner after air-drying. Keep the caps tightly placed on the stain containers to prevent evaporation. Uneven Staining • • • • • Use only clean and dry slides. Do not touch the sample area of the slides before or after preparation. Place slides at an angle for drying to prevent liquid from drying onto the slide. Inadequate mixing of stains. Keep the caps tightly placed on the stain containers to prevent contamination and evaporation. Slide Precipitate • • • • • Rinse adequately between stains and after staining (refer to Skill Box 4.14), page 127. Use clean slides. Do not allow stains to dry onto slide while staining. Change or filter stains periodically and regularly. Keep the caps tightly placed on the stain containers to prevent contamination and evaporation. 4 Table 4.20 / Bacteria Identification Organism General Information Associated Conditions Microscopic Culture Bordetella bronchiseptica • Gram-negative • Upper respiratory infection and pneumonia • Small rods • BA: small, circular, dewdrop shape with +/− beta-hemolysis; slow grower • MC: weak growth Borrelia burgdorferi • Spirochete • Lyme disease • Refer to reference laboratory for identification. • Refer to reference laboratory for identification Brucella canis • Gram-negative • Infertility, abortion, and diskospondylitis • Small, red coccobacillus in clumps • BA: round, smooth, glistening, and translucent Campylobacter spp. • Color Plate 4.10, CP-5 • Gram-negative • Does not survive outside the host ≥3 hours • Gastroenteritis, infertility, and abortion • Tiny, curved, gram-negative rods (not tightly spiraled) • Two attached together as a “seagull” or W shape • “Swarm of bees,” rapid and darting motility • Refer to reference laboratory for identification. 130 SECTION THREE: DIAGNOSTIC SKILLS Table 4.20 / Bacteria Identification (Continued) Organism General Information Associated Conditions Microscopic Culture Chlamydia • Resemble gram-negative • Obligate, intracellular parasite • Conjunctivitis and pneumonia • Small, red, pleomorphic coccobacilli in clumps • N/A Clostridium • Color Plate 4.8, CP-4 • Gram-positive • Obligate anaerobes • Resistant to most disinfectants, requires 20 minutes of boiling or 121º C in an autoclave for 20 minutes • Gastroenteritis, otitis and tetanus • Large, spore-forming rods with rounded ends • “Safety pin” appearance with a swollen, clear center and dark staining ends • BA: 1–3 mm in diameter, round to slightly irregular, raised, granular, transparent with a double zone of hemolysis • MC: no growth Escherichia coli • Gram-negative • Facultative anaerobes • Readily killed by disinfectants, sunlight, and desiccation • Genital tract infection, musculoskeletal infection, pneumonia, enteritis, abscesses, urinary tract infection, and sepsis • Small, non–spore-forming rods • BA: large, smooth, gray, mucoid colonies with +/− hemolysis • MC: red growth, lactose fermentation, hemolytic pattern Fusobacterium • Gram-negative • Obligate anaerobes • Pleuritis and abscesses • Slender, long rods with pointed ends and long beaded filaments • BA: small, smooth, convex and whitish-yellow in color colonies with a narrow zone of alpha- or beta-hemolysis Mycobacterium tuberculosis • Gram-positive • Pulmonary nodules (dogs) and gastrointestinal problems (cats) • Small, straight or slightly curved acid-fast rods, singly or in clumps • Refer to a reference laboratory for identification Mycoplasma spp. • Gram-positive • Lack a cell wall; therefore do not stain adequately enough to evaluate • Readily killed by common disinfectants • Genital tract infection, arthritis, conjunctivitis (cats) and pneumonia • Small, coccobacillus-like, non– spore-forming, no cell wall and +/− pleomorphic • Refer to a reference laboratory for identification Nocardia spp. • Gram-positive aerobes • Saprophyte in the soil • Partially acid-fast • Pleuritis and abscesses in multiple tissues • Branching, filamentous rods or coccobacilli • BA: irregularly folded, raised, smooth to rough with a dry granular texture; slow grower • MC: no growth Pasteurella spp. • Gram-negative • Facultative anaerobes • Readily killed by most common disinfectants • Conjunctivitis, genital tract infection, upper respiratory infection, pneumonia, pleuritis, abscesses and urinary tract infections • Small, non–spore-forming coccobacilli or rods • BA: round, smooth, gray colonies with +/− hemolysis • MC: no growth Proteus spp. • Gram-negative • Facultative anaerobes • Readily killed by common disinfectants, sunlight and dessication • Cystitis, urinary tract infections, diarrhea, wounds and otitis • Medium-sized non–spore-forming rods • BA: large, smooth, gray, swarming, mucoid colonies with +/− hemolysis • MC: colorless growth that may spread CHAPTER 4 / LABORATORY 131 4 Table 4.20 / Bacteria Identification (Continued) 4 Organism General Information Associated Conditions Microscopic Culture Pseudomonas spp. • Gram-negative • Killed by most common disinfectants, ↑ resistance to high dilutions of quaternary ammonium compounds and phenolic compounds • Conjunctivitis, otitis musculoskeletal infection, abscesses, and urinary tract infections • Small rods • BA: 3–5 mm in diameter, irregular, spreading, translucent, bluish-metallic sheen, betahemolysis and grape-like odor • MC: yellow-green pigmented growth with a grape-like odor Rickettsia • Resemble gram-negative • Obligate, intracellular parasite • Smallest organism able to reproduce on its own • Can not live outside the host • Rocky Mountain spotted fever, salmon poisoning disease, Ehrlichia and Hemobartonella • Small, pleomorphic coccobacilli • N/A Salmonella • Gram-negative • Readily killed by common disinfectants, sunlight, and dessication • Gastroenteritis, abortion, hepatitis, and septicemia • Small, non–spore forming rods • BA: large, smooth, gray, mucoid colonies with +/− hemolysis • MC: colorless growth Spirochetes • Color Plate 4.11, CP-5 • Gram- negative • Lyme disease, leptospirosis, • Stiff corkscrew helical rods with tight spirals • Corkscrewing motility • N/A Staphylococcus aureus/intermedius • Gram-positive • Stable, surviving for months when dried in pus or other body fluids • ↑ Resistance to common disinfectants • Conjunctivitis, genital tract infection, mastitis, pyoderma, otitis, osteomyelitis, musculoskeletal infection, pneumonia, abscesses and urinary tract infections • Cocci, often in grape-like clusters, non–spore forming, +/− capsules • BA: 4 mm in diameter, round, smooth, glistening with a double zone of hemolysis and gold pigmentation • MC: no growth Streptococcus spp. • Gram-positive • Facultative anaerobes • Remain living for weeks to months after being expelled from the body • Readily killed by common disinfectants • Conjunctivitis, genital tract infection, otitis, pneumonia, abscesses, and urinary tract infections • Cocci, +/− singly or in chains of varying lengths and non–spore forming • BA: 1 mm in diameter, round, smooth, glistening and resemble dewdrops with beta-hemolysis (Alpha and gamma-hemolysis are typically normal flora) • MC: no growth Note: BA = blood agar, MC = MacConkey agar. 132 SECTION THREE: DIAGNOSTIC SKILLS Table 4.21 / Fungi Identification Organism Associated Conditions Microscopic Culture Aspergillus • Nasal infections • Common laboratory contaminant • Preparation: clear cellophane tape with lactophenol blue or scrapings mixed with 10% sodium hydroxide • Identification: short pieces of thick, septate hyphae • • • • Blastomyces —Dermatitidis • Pulmonary nodules, internal ulcers • Abscesses • Preparation: wet mount with 20% KOH • Identification: large, oval or spherical, thick-walled with a single bud that is connected to the mother cell by a wide base • Refer to reference laboratory for confirmation by culture. Candida spp. • Color Plate 4.12 • Mycotic stomatitis (canine) • Enteritis (kittens) • Preparation: scrapings of lesions made as wet mounts with 20% KOH, India ink, or lactophenol cotton blue • Identification: thin-walled (no capsule) oval budding yeast cells and +/− pseudohyphae • • • • Coccidiodes immitis • Systemic and bone infections • Preparation: unstained wet mounts • Identification: thick-walled sporangia • Caution: Because of its zoonotic potential, refer to a reference laboratory for culture. Cryptococcus —neoformans • Paranasal and CNS infections • Preparation: A small amount of discharge is mixed on a slide with water and India ink in a 1 : 2 ratio • Identification: budding yeast-like cells with large capsules • • • • Histoplasma capsulatum • Systemic, pulmonary and gastrointestinal infections • Soil borne • Preparation: Giemsa or Wright’s method • Identification: small oval cells surrounded by a halo seen intracellularly in monocytic cells • Caution: Because of its zoonotic potential, refer to a reference laboratory for culture. Malassezia –pachydermatis • Color Plate 4.34, CP-11 • Chronic otitis externa (canine) • Pyoderma • Preparation: wet mounts with 10% NaOH • Identification: oval or bottle-shaped, small budding cells • • • • Microsporum canis • Dermatophytosis • Preparation: place a few pieces of plucked hair, scales, or crust from skin scraping, 20% KOH, and black India ink on a slide, and apply a coverslip with gentle pressure • Gently heat the slide, and let it sit for 10–15 minutes. • Identification: spores and chains of highly refractile arthrospores • Medium: dermatophyte test medium (DTM, modified Sabouraud dextrose agar) • Additive: Phenol red, pH indicator • Incubation: 2 weeks at room temperature • Identification: flat colony, white surface and silky in center, red color change to agar Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 48 hours at 77–98.6º F Identification: flat, white, and floccose, then turns green to dark green and powdery 4 Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 2 days at 77–98.6º F Identification: creamy, smooth colonies with yeastlike odor Medium: Blood agar or Sabouraud dextrose agar Additive: none Incubation: 14 days at 95–98.6º F Identification: wrinkled, whitish granular colonies to mucoid, cream to brown colonies Medium: Blood agar or Sabouraud dextrose agar Additive: Olive or coconut oil Incubation: 14 days at 77º F in a CO2 incubator Identification: greenish pigmentation CHAPTER 4 / LABORATORY 133 Handling PARASITOLOGY Fecal analysis is 1 of the most common laboratory tests run in small animal clinics. The skills required for preparing and reading these tests are minimal and are expected of every technician. Regardless of their simplicity, the result of these tests and subsequent treatment often leads to a full recovery by the patient. • Samples should be handled carefully to avoid human contamination. • Maintain a clean environment in which to run the laboratory tests. • Maintain clear records as to the procedure performed. Storage • Fecal samples can be stored in whirl pak bags, small plastic sandwich bags, plastic containers, or disposable laboratory gloves turned inside out. Fecal Collection, Handling, Storage, and Transport Tips 4 Collection • Samples can be stored indefinitely in 10% formalin (1 part feces to 9 parts formalin), with minor limitations. • Sample must be as fresh as possible because of rapid development of eggs once passed. • Owner should witness animal defecating to ensure freshness and observe for any straining, fresh blood, or other problems. • Samples should not be stored by freezing, 70% ethyl alcohol, or 100% methyl alcohol. Transport • Fresh samples not to be examined in 2 hours should be refrigerated for no longer than 24 hours. • Sample should be cooled to 39.2º F in the refrigerator and then packed on ice or cold packs for 24–48 hours. • Submit the amount equal to the size of an adult male’s thumb, at least 10 g. • Place important papers in a separate plastic bag in case of sample fluid leakage. • Sample should be clearly marked with patient’s name, number, time of collection, and whether it was refrigerated. Skill Box 4.16 / Endoparasite Examination Methods Method Uses Technique Comments Gross Examination • Consistency • Color • Blood, mucus, or adult parasites • Visualize the feces or vomitus. • Reveals conditions (e.g., blood) not seen in other methods Direct Smear: Wet Prep • Protozoa (e.g., Giardia) • Parasite burden • Bacteria (e.g., spirochetes, Cryptosporidium, Campylobacter) 1. Place a drop of saline or water with an equal amount of feces on a slide. Thoroughly mix the feces and water and smear to make a thin film over slide. 2. Remove any large pieces of feces and add a coverslip to examine. 3. Examine under ×10 for parasite eggs, ×40 for protozoal organisms, and ×100 for bacteria. • Stain can be added to the side of the coverslip for clearer identification. • No egg distortion • Not a concentrated technique (small sample size) leading to low numbers • Motility can be a helpful diagnostic aid 134 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.16 / Endoparasite Examination Methods (Continued) Method Uses Technique Comments Direct Smear: Dry Prep • Protozoa (e.g., Giardia) • Parasite burden • Bacteria (e.g., spirochetes, Cryptosporidium, Campylobacter) 1. Place a small amount of feces on a slide and thinly spread out using an applicator stick. 2. Heat fix and stain with Diff-Quik. 3. Examine under ×10 for parasite eggs, ×40 for protozoal organisms, and ×100 for bacteria. • No egg distortion • Not a concentrated technique (small sample size) leading to low numbers • Not able to judge motility of parasites Standard or Simple: Flotation • Most parasites • Parasite burden 1. Place 1–2 g feces in a suitable container (e.g., paper cup) and add flotation solution. 2. Mix the contents thoroughly with a tongue depressor and strain through a tea strainer or cheesecloth into a second container. 3. Pour this mixture into a test tube and add more flotation solution until a meniscus is formed. 4. Place a glass coverslip over the meniscus for 10–15 minutes. 5. The coverslip is then removed, placed on a slide, and examined. • Commercial fecal flotation kits available • Less efficiently recovers eggs than the centrifugal flotation method • Misses larvae that settle because of gravity Centrifugal Flotation • Most parasites • Parasite burden 1. Mix 1 tsp feces in a paper cup with enough water or flotation solution to make a semisolid suspension. 2. Place a tea strainer or cheesecloth over a second paper cup, and empty the contents on top of it. 3. Push the liquid through the strainer with the tongue depressor and then discard the solid waste. 4. Pour the strained mixture into a 15 mL centrifuge tube. 5. Fill the tube with flotation solution to form a slight positive meniscus; do not overfill the tube. 6. Place a coverslip on top of the tube. 7. Put the tube in a balanced centrifuge and spin at 1,300 RPM for 5 minutes. 8. Remove the tube and let it stand for 10 minutes. 9. Lift the coverslip directly upward and place on a glass microscope slide. • More efficiently recovers eggs than the standard flotation method • Requires a centrifuge with a horizontal rotor and the ability to hold 15-mL tubes • Misses larvae that settle because of gravity Baermann Technique • Nematode larvae 1. Fill the funnel with warmed water or physiologic saline (86º F) to cover the wire screen. 2. Spread a piece of cheesecloth or gauze square over the wire screen in the funnel. 3. Place 5–15 g feces, soil, or tissue on the cheesecloth and fold any excess cloth over the sample. Make sure that the warm water covers the sample. 4. Leave the sample undisturbed overnight (>8 hours). 5. Place a glass slide under the cut-off pipette and allow 1 drop of the liquid to fall onto the slide. 6. Apply a coverslip and examine. If the slide is negative, repeat several times for assurance. • Efficient recovery of larvae 4 CHAPTER 4 / LABORATORY 135 Skill Box 4.16 / Endoparasite Examination Methods (Continued) Method Uses Technique Comments Fecal Culture • Hookworm larvae • To distinguish between parasites that have similar-appearing eggs and cysts 1. Place feces in a glass jar rinsed with 0.1% sodium carbonate solution or on a piece of filter paper in a Petri dish. 2. Cover the container and place in a dark area for 7–10 days. There should be enough moisture in the container to produce condensation on the sides; if not, add a small amount of water. 3. After 7–10 days, rinse the container with a small amount of water, collect liquid, and centrifuge. 4. Examine the sediment with a microscope. • Guaranteed identification Wet Mount/Fecal Culture • InPouchTM • Tritrichomonas foetus Following the manufacturer’s instructions: Remove the pouch from the bag and confirm that ∼1 mL of liquid is in the upper chamber. Open the pouch and insert an applicator stick with 0.03 g of fresh feces or a coated swab into the liquid of the upper chamber. Remove the feces by gently rubbing the stick between thumb and forefinger and walls of chamber. Close the pouch and label. Wet Mount Stand the pouch upright for 15 minutes to concentrate T. foetus at the bottom of the pouch. Place the viewing clip horizontally across the pouch and then lay the pouch across the microscope and examine, paying special attention to the edges. Fecal Culture Squeeze all liquid into the lower pouch, close pouch, and incubate for 18–24 hours. Mix the pouch up and down against an edge 3–4 times. Place the viewing clip horizontally across the pouch and then lay the pouch across the microscope and examine. • The addition of excess fecal material will make the medium too cloudy to view. • If no T. foetus is seen, evaluate daily for 2–4 days and up to every other day for 12 days. • 1–10 organisms is sufficient to result in a presumptive positive test. • Fecal culture is typically more accurate than the wet mount. 4 Note: A dried tapeworm proglottid may be rehydrated by soaking in water or physiologic saline for 1–4 hours. Note: Additional fecal cytology information can be found at Skill Box 4.7 Fecal Cytology, page 95. 136 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.17 / Fecal Flotation Solutions Fecal flotation solutions are used to assist in the discovery of parasitic eggs in fecal material. The solution chosen must have a specific gravity that allows parasite eggs to float and the bulk of fecal material to sink. Because water has a specific gravity just slightly lower than many parasite eggs, sugar or salts are added to increase the solution’s specific gravity and allow the eggs to float. The desired specific gravity is between 1.2 and 1.25 g/mL. Solutions with a specific gravity >1.35 g/mL will allow both debris and parasite eggs to float, making egg identification more difficult. A specific gravity <1.10 will force both debris and parasite eggs to sink, giving no diagnosis. Solutions that are purchased premixed are preferred because of quality control. Solutions mixed in the clinical setting tend to have less quality control and give variable results. Almost all solutions will form crystals on the slide if left sitting. Media Preparation Specific Gravity General Information Magnesium Sulfate • Magnesium sulfate: 400 g • Tap water: 1,000 mL 1.20 • Readily available and inexpensive Sodium Chloride • Sodium chloride: 400 g • Tap water: 1,000 mL • Stir while adding the sodium chloride to water. Heating is not necessary, but speeds the dissolution. 1.18–1.20 • Readily available and inexpensive • Corrodes expensive laboratory equipment • Severely distorts eggs Sodium Nitrate • Sodium nitrate: 400 g • Tap water: 1,000 mL • Stir while adding the sodium nitrate to water. Heating is not necessary, but speeds the dissolution. 1.20 • • • • Floats the greatest percentage of eggs Can be purchased in a ready-to-mix solution Distorts the eggs after 15 minutes May not be readily available and more expensive Sugar Solution, Sheather’s Solution • Granulated sugar: 454 g • Tap water: 355 mL • Dissolve sugar in water by heating on low heat and stirring. Add 2 mL of 37% formaldehyde or phenol crystals to prevent bacterial growth. 1.27–1.33 • • • • Readily available and inexpensive Does not distort eggs or crystallize Floats an adequate percentage of eggs Best if used with centrifugal flotation technique Zinc Sulfate • Zinc sulfate: 371 g • Tap water: 1,000 mL • Stir while adding the zinc sulfate to water. Heating is not necessary, but speeds the dissolution. 1.18 • Best for intestinal protozoa (e.g., Giardia) • Light must be ↓ and focused immediately under the coverslip. • Floats a high percentage of eggs Note: If a fecal sample is left for more than 1 hour, the eggs may become waterlogged, resulting in distortion or sinking to the bottom. CHAPTER 4 / LABORATORY 137 4 Skill box 4.18 / Blood Parasite Examination Methods Method Uses Technique General Information Direct Examination • Microfilariae 1. Add 1 drop of blood to a slide. 2. Add a coverslip and examine for movement. • Small sample volume owing to low sensitivity Thin Blood Smear • Trypanosomes, protozoans, and rickettsia 1. Place a drop of blood near 1 end with a glass slide laying on a flat surface 2. Place another slide at a 30%–40% angle in front of the blood. 3. Back the slide up until the blood runs along the edge of the second slide. 4. Then gently and steadily push the slide forward and off the first slide, producing a smear with a feathered edge. 5. Air-dry, +/− add stain and examine. • Small sample volume Thick Blood Smear • Microfilariae, protozoa, and rickettsiae 1. Place 3 drops of blood on a slide, spread the drop out with a wooden applicator stick into a 2-cm circle. 2. Air-dry the slide. 3. Place the slide in a slanted position in a container of distilled water. 4. Once the smear losses its red color, remove it, and allow it to air-dry. 5. Place the slide in methyl alcohol for 10 minutes 6. Add Giemsa stain for 30 minutes. 7. Rinse slide and examine. • Larger sample volume Buffy Coat • Microfilariae 1. Fill and centrifuge an Hct tube for 3 minutes. 2. Using a file or glass slide, score the tube just below the buffy coat and snap apart. 3. Tap the tube until the buffy coat drops onto a glass slide. 4. Add a drop of saline and stain, place a coverslip on, and examine. • Does not allow differentiation of microfilariae species Modified Knott’s Technique • Microfilariae 1. Mix 1 mL whole unclotted blood with 9 mL 2% formalin in a test tube. 2. Centrifuge at 1,300–1,500 rpm for 5 minutes. 3. Pour off the supernatant and add 2–3 drops of stain to the sediment. 4. With a pipette, mix the sediment and stain. 5. Place a drop on a glass slide, apply a coverslip, and examine under ×10. • Allows differentiation of microfilariae species 4 138 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 4.19 / Ectoparasite Examination Methods Method Uses Technique General Information Gross Examination • Lice, mites, ticks, flies, or fleas 1. Visualize the ectoparasite on the animal or by using a flea comb. • Limited number of parasites visible Cellophane Tape • Lice or mites 1. Bend the cellophane tape into a loop with the sticky side out. 2. Press the tape against the animal’s skin. 3. Put 1 drop of water on a slide and lay tape over it and press down. 4. Examine under a microscope. • Limited number of parasites visible 1. Place a drop of mineral oil on a glass slide. 2. Roll the swab or material collected in the mineral oil to deposit any debris. 3. Place a coverslip on the slide and examine with a microscope, using 4× magnification. • Most thorough technique for ectoparasite diagnosis Microscopic Examination • Most ectoparasites 4 Table 4.22 / Endoparasites (See figures in Color Plate 11–13) Prevention of human infection from endoparasites involves proper hygiene (e.g., washing hands and properly cooking food), isolation of infected animals, and quarantine of newly acquired animals. Each fecal sample should be thought of as a zoonotic risk and treated appropriately. Figure 4.35 Relative size of parasite eggs. Note: Adapted from Veterinary Parasitology Reference Manual by William J. Foreyt. Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Ancylostoma caninum ZOONOTIC • Common Name: Southern hookworm • Type: Nematode • Affected Species: Canine • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.36 Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 2 weeks • Anemia, weakness, inappetance, poor growth, dry cough, diarrhea, constipation, and dark tarry stools • Fecal flotation • Egg: oval or ellipsoid, capsule-shaped, 8–16 cells inside a thin wall • Sample must be <48 hours old because eggs larvate rapidly in the external environment. • • • • • • • • • • • Butamisole Dichlorvos Diethycarbamazine/oxibendazole Febantel/praziquantel Fenbendazole Ivermectin Lufenuron + milbemycin Mebendazole Milbemycin oxime Moxidectin Pyrantel CHAPTER 4 / LABORATORY 139 Table 4.22 / Endoparasites (Continued) 4 Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Ancylostoma tubaeforme ZOONOTIC • Common Name: Feline hookworm • Type: Nematode • Affected Species: Feline • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.37 Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 3–3.5 weeks • Interdigital dermatitis, pulmonary lesions, anemia and poor hair coat • Fecal flotation • Egg: oval or ellipsoid, capsule shaped, 8–16 cells inside a thin wall • Sample must be <48 hours old because eggs larvate rapidly in the external envirnoment. • • • • • • Dichlorvos Fenbendazole Milbemycin oxime Mebendazole Moxidectin Pyrantel Cryptosporidium ZOONOTIC • Common Name: N/A • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Heating >131º F for 15–20 minutes, thorough drying, 5% ammonia solution, and formaldehyde • Environment: Resistant for months • Image: Color Plate 4.38 Oocysts passed → ingested by definitive host → develop in the ileum and cecum • Prepatent period: 2–7 days • Asymptomatic or diarrhea • Fecal flotation, acid-fast staining, negative staining, ELISA and IFA tests • Oocysts: oval to spherical, thick-walled and sporulated • Note: difficult to distinguish from yeast cells on fecal flotations • • • • Clindamycin Tylosin Azithromycin Paromomycin Dipylidium caninum ZOONOTIC • Common Name: Flea tapeworm • Type: Cestode • Affected Species: Canine and feline • Image: Color Plate 4.39 Proglottids passed and rupture to release thousands of eggs → ingested by intermediate host (flea and biting lice) → development → definitive host ingests the intermediate host → attaches to lining of small intestines to mature • Prepatent period: 4 weeks • Anal pruritus, chronic enteritis, vomiting, or nervous system disorders • Fecal flotation or visual examination of feces, perianal area, or bedding • Egg: double-pored, rice or cucumber seed appearance, oblong packets of 20 eggs or less • Epsiprantel • Febantel/Praziquantel • Praziquantel Dirofilaria immitis ZOONOTIC • Common Name: Heartworm • Type: Nematode • Affected Species: Canine and feline • Image: Color Plate 4.40 • Intermediate host (mosquito) must carry the larva for 15–17 days with the temperature ≥58º F → intermediate host infects definitive host → larva passes from venous circulation to heart → resides in pulmonary arteries and right ventricle of heart → microfilaria circulate in blood and are picked up by intermediate host (mosquito) • Prepatent period: 24 weeks • Murmur, lack of stamina, weight loss, chronic cough, obstruction of pulmonary vessels, and congestive heart failure • Knott’s test, buffy coat examination, direct blood smear, millipore filtration of blood, and various serologic tests for antigen of adult worm • Microfilaria: straight with 1 tapered end and 1 straight end Adulticides • Caparsolate • Malarsomine • dihydrochloride Microfilariacides • Diethylcarbamazine • Diethycarbamazine/oxibendazole • Dithiazine • Ivermectin • Levamisole • Milbemycin oxime • Moxidectin • Selamectin 140 SECTION THREE: DIAGNOSTIC SKILLS Table 4.22 / Endoparasites (Continued) Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Echinococcus granulosus and multiocularis ZOONOTIC • Common Name: Canine and feline tapeworm, respectively • Type: Cestode • Affected Species: Canine and feline • Image: Color Plate 4.41 Proglottids passed → ingested by intermediate host (e.g., cattle, swine, sheep and rodents) → attaches to liver → definitive host ingests the intermediate host → attaches to lining of small intestines to mature • Prepatent period: 4 weeks • Diarrhea • Hydatid cyst disease in intermediate host • Fecal flotation or purging the animal and collecting the clear mucus at the end • Egg: ovoid containing a single oncosphere with 3 pairs of hooks • Note: indistinguishable from Taenia spp. eggs • Mebendazole • Praziquantel Filaroides osleri • Common Name: Tracheal worm and canine lungworm • Type: Nematode • Affected Species: Canine Eggs passed → ingested (passed from dam to pup through grooming or regurgitated meals) → migrate to small intestines and then to lungs to develop → migrate to oral cavity or passed through feces • Prepatent period: 10 weeks • Coughing and chronic tracheobronchitis with nodule formation in large airways • Fecal flotation, Baerman technique, and sputum smear • Larva: short, with an Sshaped tail • Albendazole • Ivermectin Giardia ZOONOTIC • Common Name: Giardia • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Bleach and quaternary ammonium • Image: Color Plates 4.12 and 4.42 Eggs passed → ingested → migrate to small intestines • Prepatent period: 5–7 days • Asymptomatic or diarrhea (appearing pale and greasy with a foul odor) • Fecal flotation, direct fecal smear, and IFA • Active form: pear-shaped with the anatomy resembling a face of crossed eyes, nose, and a mouth • Furazolidone • Metronidazole Isospora canis/felis ZOONOTIC • Common Name: Coccidia • Type: Protozoa • Affected Species: Canine and feline • Disinfection: Incineration, steam cleaning, immersion in boiling water and 10% ammonia solution • Prevention: Insect and rodent control and sanitation • Environment: Extremely resistant to environmental conditions • Image: Color Plate 4.43 Eggs passed, usually by mother → ingested, often by puppy or kitten → develop to a trophozoite → migration to intestines • Prepatent period: 1–2 weeks • Asymptomatic or diarrhea progressing to vomiting, inappetance, and dehydration • Fecal flotation • Egg: small, oval, and thin-walled • Sporulated: 2 sporocysts per egg • Unsporulated: 1 cell stage inside egg • • • • 4 Furazolidone Sulfadiazine + trimethoprim Sulfadimethoxine Toltrazuril CHAPTER 4 / LABORATORY 141 Table 4.22 / Endoparasites (Continued) Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Nanophyetus salminocola ZOONOTIC • Common Name: Salmon poisoning fluke • Type: Trematode • Affected Species: Canine Eggs passed by definitive host (e.g., raccoon) → ingested by intermediate host (snail) → larva passed → ingested by intermediate host (salmon) → salmon ingested by definitive host (e.g., dog) → develop in intestines • Prepatent period: 1 week • Lymph-adenopathy, depression, vomiting, and hemorrhagic enteritis • Caused by the rickettsial agent (Neorickettsia helminthoica) carried by the fluke • Fecal flotation or fecal smear • Egg: gold, operculum at 1 end and blunt point at opposite end Fluke • Praziquantel Rickettsial organism • Chloramphenical • Doxycycline • Oxytetracycline • Tetracycline Spirocerca lupi • Common Name: Esophageal worm or park worm • Type: Nematode • Affected Species: Canine Egg passed by definitive host (e.g., dog) → ingested by intermediate host (beetle) → ingested by paratenic host (e. g., lizards, birds, rodents) or definitive host (e.g., dog) → larva penetrate stomach wall and migrate through the arteries to the esophagus → forms a fistula and releases egg in the feces • Prepatent period: 5–6 months • Dysphagia, regurgitation, vomiting, esophageal neoplasia, hypersalivation, hypertrophic osteopathy • Fecal flotation (specific gravity >1.036) or fecal smear • Egg: thick walled, ellipsoid embryonated egg • Disophenol sodium • Ivermectin • Doramectin Taenia pisiformis • Common Name: Tapeworm • Type: Cestode • Affected Species: Canine • Image: Color Plate 4.44 Proglottids passed → ingested by intermediate host (e.g., rabbit and ruminant) → attaches and develops in peritoneal cavity → definitive host ingests the intermediate host → develops in the small intestines • Prepatent period: 8 weeks • Enteritis and intestinal obstruction • Fecal flotation or visual exam of feces, perianal area or bedding • Egg: round and containing a single oncosphere with 3 pairs of hooks • Each proglottid carries many eggs • • • • • Epsiprantel Febantel + praziquantel Fenbendazole Mebendazole Praziquantel Taenia taeniaeformis • Common Name: Feline tapeworm • Type: Cestode • Affected Species: Feline Proglottids passed → ingested by intermediate host (e.g., rodent) → attaches and develops in the liver → definitive host ingests the intermediate host → develops in the small intestines • Prepatent period: 5–6 weeks • Diarrhea and intestinal blockage • Fecal flotation or visual examination of feces, perianal area, or bedding • Egg: ovoid containing a single oncosphere with 3 pairs of hooks • Each proglottid carries many eggs • • • • • Epsiprantel Febantel + praziquantel Fenbendazole Mebendazole Praziquantel 4 142 SECTION THREE: DIAGNOSTIC SKILLS Table 4.22 / Endoparasites (Continued) Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Toxascaris leonina ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Canine and Feline • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.45 Eggs passed → ingested by definitive host or intermediate host (e.g., mice) → definitive host ingests intermediate host → attaches and develops in small intestines • Prepatent period: 8–10 weeks • Chronic diarrhea, vomiting, constipation, and unthriftiness • Fecal flotation or visual examination of feces • Egg: spherical to ovoid, unembyronated, light cytoplasm, and a smooth outer shell • • • • • • • Dichlorvos Diethylcarbamazine Fenbendazole Milbemycin oxime Mebendazole Piperazine Pyrantel Toxocara canis ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Canine • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.45 Eggs passed → ingested via environment or paratenic host → hatch in small intestines and penetrate mucosa → migrate through the liver and heart until the lungs → develop in lungs → coughed up and swallowed → mature in the small intestines for 4–6 weeks • Prepatent period: 4–6 weeks • Distended abdomen, weakness, unthriftiness, and diarrhea • Fecal flotation or visual examination of feces or vomitus • Egg: spherical, unembyronated, deeply pigmented center, and a rough, pitted outer shell • • • • • • • • • Dichlorvos Diethylcarbamazine Diethycarbamazine/oxibendazole Febantel + Praziquantel Fenbendazole Mebendazole Milbemycin oxime Piperazine Pyrantel Toxocara cati ZOONOTIC • Common Name: Ascarid, roundworm • Type: Nematode • Affected Species: Feline • Disinfection: Bleach • Environment: Eggs can remain infective in the soil for months to years • Image: Color Plate 4.46 Eggs passed → ingested via environment or paratenic host → hatch in small intestines and penetrate mucosa → migrate through the liver and heart until the lungs → develop in lungs → coughed up and swallowed → mature in the small intestines for 4–6 weeks • Prepatent period: 7–8 weeks • Stunted growth and damage caused by migrations • Fecal flotation • Egg: spherical, unembyronated, deeply pigmented center, and a rough, pitted outer shell • • • • • • • • Dichlorvos Diethylcarbamazine Fenbendazole Lufenuron Mebendazole Piperazine Pyrantel Selamectin CHAPTER 4 / LABORATORY 4 143 Table 4.22 / Endoparasites (Continued) 4 Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Toxoplasma gondii ZOONOTIC • Common Name: Toxoplasmosis • Type: Protozoa • Affected Species: Feline • Environment: Can live in the soil for months to >1 year • Image: Color Plate 4.47 Oocysts passed → ingested via environment, intermediate host (most warm-blooded vertebrates) or transplacental → migrate to small intestines and extraintestinal dissemination elsewhere via blood and lymph • Prepatent period: 3–10 days for ingestion of cysts and 20–40 days for oocysts • Asymptomatic or transient diarrhea, anorexia, depression, fever, and clinical signs dependent on site and extent of injury from migration (e. g., CNS, hepatic, pulmonary) • Fecal flotation, ELISA, or agglutination procedures • Oocysts: oval and unsporulated • • • • Clindamycin Pyrimethamine Sulfadiazine + trimethoprim Toltrazuril Trichuris vulpis • Common Name: Whipworm, fecal jewel • Type: Nematode • Affected Species: Canine • Disinfection: Diluted sodium chloride • Environment: very resistant • Image: Color Plate 4.48 Eggs passed → ingested → penetrate and develop in small intestines → migrate to cecum and develop for 60–80 days • Prepatent period: 9–12 weeks • Weight loss, intermittent and chronic diarrhea and typhlitis • Fecal flotation • Egg: thick, brown-yellow symmetrical shell with clear polar plug at each end and unembyronated • • • • • • Diethycarbamazine/oxibendazole Febantel + praziquantel Fenbendazole Ivermectin Mebendazole Milbemycin oxime Uncinaria stenocephala ZOONOTIC • Common Name: Northern canine hookworm • Type: Nematode • Affected Species: Canine and feline • Disinfection: Bleach • Environment: Can live in cool, moist soil for several weeks • Image: Color Plate 4.49 Eggs passed → ingestion, percutaneous, prenatal and transmammary → lungs for development → coughed up and swallowed → small intestines to mature • Prepatent period: 2 weeks • Weakness, inappetance, poor growth, and diarrhea • Fecal flotation • Egg: oval or ellipsoid, capsule shaped, 8–16 cells inside a thin wall • Sample must be <48 hours because eggs larvate rapidly in the external environment • • • • • • Dichlorvos Fenbendazole Ivermectin Mebendazole Milbemycin oxime Pyrantel 144 SECTION THREE: DIAGNOSTIC SKILLS Table 4.23 / Ectoparasites (See figures in Color Plate 13–15) Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Cheyletiella ZOONOTIC • Common Name: Fur mite of dogs and cats and walking dander • Type: Mite • Affected Species: Canine and feline • Human Risk: Low • Image: Color Plate 4.50 • Ingest: keratin debris and tissue fluid • Location: skin • Transmission: direct contact and contact through inanimate objects • Life Cycle: 18–21 days • Asymptomatic, mild alopecia, dandruff, and pruritus • Scrape margins of lesions, flea comb, visual, or cellophane tape • Adult: body shape resembles a shield or acorn, hook-like accessory mouth parts and comb-like structures at the tip of each leg • Ivermectin • Selamectin Ctenocephalides canis/felis • Common Name: Flea • Type: Flea • Affected Species: Canine and Feline • Human Risk: Low • Image: Color Plate 4.51 • Ingest: blood • Location: head and base of tail • Transmission: direct contact or through contact with inanimate objects • Life Cycle: 21 days–>1 year • Flea bite dermatitis, anemia, pruritus, red lesions, hair loss, and ulcers • Visual and flea comb • Adult: medium brown to mahogany in color, laterally flattened body, 2–8 mm long with pronotal and genal combs • Transmit Dipylidium and Hemobartonella spp. • • • • • • • • Cuterebra • Common Name: Rodent botfly, warbles, and wolves • Type: Fly • Affected Species: Canine and feline • Human Risk: Low • Ingest: N/A • Location: face and neck region, can be found on any furred area • Transmission: contact with rodent burrow or eggs from an adult fly • Life Cycle: 3–4 weeks • Cutaneous lump with a breathing hole • Visual Larvae • 2nd Stage: cream to white, toothlike spines and 5– 10 mm long • 3rd Stage: large, coal black, heavily spined, and up to 3 cm long • Surgical removal of larvae • Note: do not crush larva when removing, because it may cause anaphylaxis • Wound treatment Demodex canis • Common Name: Follicular mange mite, red mange, or puppy mange • Type: Mites • Affected Species: Canine • Human Risk: None • Image: Color Plate 4.52 • Ingest: unknown • Location: hair follicles and sebaceous glands • Transmission: direct contact from dam to pup; otherwise not contagious between hosts • Life Cycle: 21 days • Alopecia of muzzle, face, and forelegs; erythema, 2º bacterial pyoderma, and pruritus • Deep skin scrapings on squeezed skin or biopsy • Adult: cigar-shaped, 8 stubby legs at anterior end of body, and ¼ cm long • • • • Dermacentor variabilis/andersoni • Common Name: American dog tick and wood tick • Type: Tick • Affected Species: Canine • Human Risk: High • Image: Color Plate 4.53 • • • • • • Asymptomatic or vasculitis • Intermediate host for Rocky Mountain spotted fever, tularemia, and other Rickettsia spp. • Visual • Adults: blue-gray with white markings on shield • • • • • Ingest: blood Location: whole body Transmission: contact Life Cycle: 3 months–2 years Tick must be attached for 5–20 hours to transmit disease 4 Fipronil Imidacloprid Lufenuron Methoprene Nitenpyram Pyrethrins/pyrethroids Pyriproxyfen Selamectin Amitraz 0.025% Ivermectin Milbemycin oxime Multivitamin/fatty acid supplement • Antibiotics • Benzoyl peroxide 5% (gel or shampoo) aids in penetration in the follicles when used with Amitraz Dichlorvos Fipronil Pyrethrins Pyriproxyfen Selamectin CHAPTER 4 / LABORATORY 145 Table 4.23 / Ectoparasites (Continued) 4 Parasite Transmission Route Clinical Signs Diagnostics Common Treatments Linognathus setosus • Common Name: Sucking louse of dogs • Type: Lice • Affected Species: Canine • Human Risk: Low • Environment: Live 7 days off host • Image: Color Plate 4.54 • • • • • Ingest: blood Location: whole body Transmission: contact Life cycle: 3–4 weeks Definitive host: canine and feline • Skin irritation, itching, dermatitis, alopecia, anemia, and roughened hair coat • Visual • Adult: dorsoventrally flattened, red to gray in color, head is more narrow than the widest part of the thorax, and 1st pair of claws smaller than 2nd and 3rd pairs • Fipronil • Ivermectin • Pyrethrins Otodectes cynotis • Common Name: Ear mite • Type: Mite • Affected Species: Canine and feline • Human Risk: N/A • Image: Color Plate 4.55 • • • • Ingest: epidermal debris Location: ear and base of tail Transmission: contact Life Cycle: 18–21 days • Shaking of head, irritation, otitis media, hematomas, head tilt, circling, and convulsions • Visual or ear swab • Adult: oval with 8 legs, fused head and thorax, short unjointed pedicle with suckers on the end of some of the legs • Clean the ear of all crusty debris. • Ivermectin • Milbemycin oxime • Selamectin Rhipicephalus sanguineus • Common Name: Brown dog tick • Type: Tick • Affected Species: Canine • Image: Color Plate 4.56 • • • • Ingest: blood Location: whole body Transmission: contact Life Cycle: 6 weeks–1 year • Anemia • Intermediate host for babesiosis and ehrlichiosis • Visual • Adult: brown with prominent lateral extensions on head, giving a hexagonal appearance • • • • • Dichlorvos Fipronil Pyrethrins Pyriproxyfen Selamectin Sarcoptes scabiei canis ZOONOTIC • Common Name: Mange mite or scabies • Type: Mite • Affected Species: Canine • Human Risk: low • Image: Color Plate 4.57 • Ingest: interstitial fluid • Location: ears, lateral elbows, and ventral abdomen • Transmission: contact • Life Cycle: 2–3 weeks • Severe itching, dry and thickened skin, erythema, papular rash, scaling, crusting, and excoriations • Deep skin scraping • Adults: oval with 8 legs, fused head and thorax, long unjointed pedicel with suckers on the end of some of the legs • • • • • Ivermectin Amitraz Benzyl benzoate Lime-sulfur Selamectin Trichodectes canis • Common Name: Biting louse of dogs • Type: Lice • Affected Species: Canine • Environment: Live 7 days off host • Image: Color Plate 4.58 • • • • • Itching, rough hair coat, and dermatitis • Visual • Adult: dorsoventrally flattened, yellow, large rounded head; head is wider than any other part of the body, 2–4 mm • Pyrethrins 146 SECTION THREE: DIAGNOSTIC SKILLS Ingest: skin and hair Location: whole body Transmission: contact Life Cycle: 3–4 weeks URINALYSIS • Centrifuge the sample at 500–3000 rpm for 3–5 minutes. Urinalysis is one of the most frequently performed laboratory tests in small animal clinics. Due to the filtering nature of the urologic system, information gained from this test may assist the veterinarian in a final diagnosis. Rarely does the urinalysis alone provide the diagnosis, but when interpreted along with clinical signs, blood chemistries, and other diagnostic tests, a diagnosis can be made. Even though this is a routinely done lab test, special care must be taken to ensure accurate results. Slight changes can make large alterations in the final results. As a technician, performing a complete urinalysis with great skill is a must. • Gently pour off the supernatant to avoid disrupting the remaining pellet. Urine Collection, Handling, Storage, and Transport Tips Collection • Collect before the administration of any medication, if possible. • Morning, prepandial samples offer the most accurate specific gravity, pH and cellular components, but allow for the degeneration of casts overnight in the bladder. • Collection containers must be clean, well rinsed, and free of any disinfectant residues. • Gently mix the pellet to avoid cellular damage. Note: Applying the brake to produce an abrupt stop may resuspend the sediment and alter results. Storage • Samples at room temperature should be examined within 60 minutes. • Samples can be refrigerated for 6–12 hours in a covered container. • Refrigerated samples tend to form crystals. • Samples may be frozen for chemistry tests, but cellular components will be destroyed. Transport • Add 1–2 drops of serum to the sample to preserve cell morphology. • Add 1 drop of 40% formalin to each ounce of urine. Urine Examination/Urinalysis • Collect at least 3–5 mL of urine. • See Skill Box 12.8, page 434, and Skill Box 12.10, page 435, for procedural information on urine collection. Handling • Samples should be covered immediately to avoid pH changes and contamination. • Samples with a delay of examination of >1 hour should be refrigerated, delay in examination can lead to changes in all aspects of a urinalysis. • Thoroughly mix a sample before examination. All urine samples should be evaluated for the following physical properties. Each of the assessments listed below is observed through a visual examination of the sample, except the specific gravity. The specific gravity is obtained with a refractometer, which accurately measures the amount of solids dissolved in a urine sample. The most accurate results are obtained with the supernatant, as it is free of cellular debris that may give false increases. The refractometer should be checked daily to ensure its calibration is set correctly. Using 1 drop of distilled water, the specific gravity reading should be 0.00. • Slowly warm refrigerated samples up to room temperature before examination and likewise, allow urine to cool down to room temperature after collection. CHAPTER 4 / LABORATORY 147 4 Table 4.24 / Gross Examination Physical Property Observation Definition Associated Conditions Color Yellow • Any shade of yellow is considered normal. • Variations are often attributable to changes in concentration (e.g., clear with low USG). • N/A Red or red/brown • Cloudy, red urine is hematuria with intact RBCs. • Clear, red urine is hemoglobinuria with free hemoglobin. • UTI, cystitis, trauma, neoplasia, urolithiasis Brown • Contains myoglobin • Muscle cell lysis Yellow/brown or yellow/green • Contains bile pigments • Liver disease White • Contains leukocytes • UTI, cystitis, heavy crystalluria Small amount • Normal when sample is shaken • N/A Large amount • Contains protein • Kidney disease, fever, excessive exercise Green • Contains bile pigments • Liver disease Ammonia • Breakdown of urease • UTI, cystitis Sweet, fruity odor • Contains ketones and/or glucose • Diabetes mellitus Canine • 1.015–1.045 Feline • 1.035–1.060 • Normal • Measurement of the density of urine compared with pure water • N/A Canine • >1.045 Feline • ≥1.060 • Hyperthenuric • If dehydrated; canine: ≥1.030; feline: ≥1.035 • False ↑: ↑ glucose and protein • ↑ Water intake or excretion of solutes • Cold urine produces a falsely high USG. ≤1.007 • Hypothenuric • ↓ Water intake, pyometra, liver disease, kidney disease, diuretics, or diabetes insipidus Clear • Normal • N/A Cloudy or flocculent • Contains cellular components • UTI Polyuria • ↑ Urine production; pale with a ↓ USG (≤1.020) • Nephritis, diabetes mellitus, diabetes insipidus, pyometra, liver disease, and kidney disease Oliguria • ↓ Urine production • ↓ Water intake, fever, shock, heart disease, and dehydration Pollakiuria • Frequent urination • UTI, urolithiasis, and crystalluria Anuria • Complete lack of urine output • No urine output in 12 hours • Urinary obstruction, urinary bladder rupture, and death 4 Foam Odor Specific Gravity (USG) Transparency Volume 148 SECTION THREE: DIAGNOSTIC SKILLS Preparation Chemistry strip evaluation provides detection of elements present in a urine sample that may or may not be seen during visual examination or microscopic evaluation. Because chemistry strips provide many false-negative results, both a visual examination and a microscopic examination should always be performed. Chemistry strip bottles should be kept at room temperature and away from intense light, moisture, and heat. Strips can be immersed in a urine sample for 2–3 seconds to allow saturation of the pads. Extended time may lead to test reagents leaking into the urine sample. A pipette or dropper also may be used to saturate each pad and then turning the strip on its side and tapping to eliminate excess urine. Allowing urine to run down the test strip can allow mixing of the chemical pads altering the results. The results are then read at the time indicated by the manufacturer in consistent artificial light to avoid the fluctuations seen with natural light. The color change can be subjective and also altered by the presence of urine pigments. (e.g., bilirubin, hemoglobin). Table 4.25 / Chemistry Strip Examination Chemical Property Observation Definition Associated Conditions Bilirubin Bilirubinuria • A byproduct from the breakdown of hemoglobin • Trace amounts found in dogs if USG is ≥1.030, but not common in cats • False negative: exposure to light • Confirmation tests: Ictotest • Hemolytic anemia, bile duct obstruction, liver disease, fever, and prolonged fasting or starvation Blooda Hematuria • Presence of intact RBCs • After centrifugation, urine will appear clear with a red pellet. • UTI, cystitis, renal disease, strenuous exercise, trauma, and genital tract contamination Hemoglobinuria • Presence of free hemoglobin, typically caused by intravascular hemolysis • After centrifugation, urine will remain tinted red. • Hemolytic anemia, severe burns, incompatible transfusions, leptospirosis, babesiosis, systemic lupus erythematosus, and metal toxicity Myoglobinuria • Presence of myoglobin typically due to muscle damage • Urine is dark brown to black. • Muscle damage Glucose Glucosuria • Appears if blood glucose threshold is exceeded BG values • Canine: >180 mg/dL • Feline: >300 mg/dL • Not detectable in the urine of normal animals • False negatives: cold urine • Diabetes mellitus, Cushing’s disease, chronic liver disease, high carbohydrate meal, stress, fear, restraint, administration of IV glucose, and Fanconi’s syndrome Ketones Ketonuria • • • • • • • Diabetes mellitus, liver disease, persistent fever, high-fat diets, starvation, fasting, and long-term anorexia Formed from the breakdown of fatty acids Not detectable in the urine of normal animals Produces a sweet, fruity smell False-negative: delayed analysis False-positives: pigmented urine Confirmation tests: Acetest CHAPTER 4 / LABORATORY 149 4 Table 4.25 / Chemistry Strip Examination (Continued) Chemical Property Observation Definition Associated Conditions pH Normal • Concentration of H+ ions, a measure of the degree of alkalinity or acidity • Canine: 5.2–6.8 • Feline: 6.0–7.0 • N/A Alkaline • ↑ Concentration of H+ ions • <7.0 • False-increases: delayed analysis • Postprandial alkaline tide, plant diets, UTI, metabolic and/or respiratory alkalosis, distal renal tubular acidosis, urine retention, and certain drugs (e.g., bicarbonate, citrate) Acidic • ↓ Concentration of H+ ions • >7.0 • Protein diets, metabolic or respiratory acidosis, fever, starvation, excessive muscular activity, chloride depletion, and certain drugs (e.g., DL-methionine, furosemide) Protein Proteinuria • Measurement of albumin and globulins • Only found in trace amounts in normal urine • Always interpret in light of USG and contents of urine sediment • False positives: ↑ USG, ↑ pH, pigmented urine, detergent contamination • Confirmation tests: sulfosalicyclic acid test, microalbuminuria test (e.g., Heska ERD screen) • Glomerulonephritis, glomerular amyloidosis, multiple myeloma, parturition, estrus, and UTI Protein : Creatinine Ratio Normal • Quantifies level of proteinuria as significant or not • Canine: ≤0.3 • Feline: ≤0.6 • N/A Increased • ↑ Urine protein loss • >1 • Chronic interstitial nephritis, glomerulonephritis, and amyloidosis 4 a To differentiate between hemoglobinuria and myoglobinuria, compare plasma and urine simultaneously. Plasma and urine will both appear red with the presence of hemoglobin, and only urine will appear red to brown with myoglobin. Sediment Examination A microscopic examination of the urine sediment should be a part of every routine urinalysis. It is used to confirm findings from gross examination and chemistry strip examination. Much additional information can be gained from a microscopic examination that cannot be determined in any other method. Samples collected first thing in the morning or after several hours of water deprivation provide the most diagnostic information. The increased concentration of these samples increases the likelihood of finding formed elements. Each laboratory needs to determine their normals and urine procedures. Commonly, a standard amount of 5 mL urine is centrifuged and poured off, leaving the pellet and approximately 0.3 mL urine in the tube. The remain150 SECTION THREE: DIAGNOSTIC SKILLS ing urine and pellet are mixed together, and 1 drop is placed on a slide. A coverslip is placed over the drop, and the sample may be read either stained or unstained. When examining an unstained sample, achieving proper light adjustment (e.g., lower stage slightly or partially close diaphragm) of the microscope to view refractile elements is important. The entire slide is examined with low power to look for areas of cell clusters, casts, cellularity; paying attention to the periphery. Casts and crystals are evaluated at low power and reported as #/lpf (low-power field). RBCs, WBCs, and epithelial cells are examined with high power and reported as #/hpf (high-power field). Bacteria and sperm are examined under high power and reported as rare through 4. Reporting of Bacteria and Sperm Rare—only a few seen after scanning numerous fields 1+: <1/hpf 2+: 1–5/hpf 3+: 6–20/hpf 4+: >20/hpf 4 Table 4.26 / Sediment Examination (See figures in Color Plate 15–22) Bacteria Bacteria are not normally found in properly collected normal urine samples. Its presence with WBCs often indicates a bacterial infection, whereas the absence of WBCs typically indicates a contaminated sample. A sample properly collected via cystocentesis or catheterization should be sterile and any presence of bacteria is significant (e.g., diabetes mellitus, Cushing’s disease, and glucocorticoid treatment). See color plates 4.59 and 4.61. Note: Normal brownian movement may often be confused with bacteria in unstained sediments. Component Appearance Definition Associated Conditions Cocci • Circular bacteria in singles, pairs, or chains • Refract light and have brownian movement • Confirm with gram stain of an air-dried smear of urine; cocci will be gram-positive • Difficult to detect if <100,000 bacteria/mL • Acid pH: Enterococcus and Streptococcus spp. • Alkaline pH: Staphylococcus spp. • UTI, cystitis, pyelonephritis, metritis, prostatitis, vaginitis Bacilli • Rod-shaped bacteria in singles, pairs, or chains • Refract light and have brownian movement • Difficult to detect if <10,000 bacteria/mL • Acid pH: E. coli • Alkaline pH: Proteus spp. • UTI, cystitis, pyelonephritis, metritis, prostatitis, vaginitis Blood Cells Blood cells are classified by number per high power field (#/hpf). Blood cells are thought to always be significant unless reviewed against other factors affecting the animal. For example, an animal with only a few RBCs and no other abnormalities may have received trauma through a catheterization procedure. WBCs are always thought to be significant, because they typically only appear with some level of an infection, unless contamination of infected genitalia takes place. WBCs do not need to be classified into type; by the time they reach the bladder, they have degenerated to an unrecognizable state. The presence of WBCs should always result in an in-depth look for bacteria. RBCs • Color Plate 4.64 • Color Plate 4.69 • Smooth edges, small, and biconcave • Size: 6–7 μm • Unstained: pale, yellow to orange disks without nuclei • Stained: varying color from light pink to dark red • Crenated: ruffled edges and slightly darker • Lysed: colorless rings of varying size • Dilute urine may show larger, swollen and globular RBCs • Normal: Voided: 0–8/hpf Catheter: 0–5/hpf Cystocentesis: 0–3/hpf • Atraumatic technique will produce the above numbers, multiple attempts may ↑ the number of RBCs • Cystitis, neoplasia, calculi, inflammation, necrosis, trauma, bleeding disorder CHAPTER 4 / LABORATORY 151 Table 4.26 / Sediment Examination (Continued) Component WBCs • Color • Color • Color • Color Plate Plate Plate Plate 4.60 4.62 4.63 4.64 4 Appearance Definition Associated Conditions • Round with granular appearance (distinct nuclei) • Size: 10–14 μm • WBCs size ↑ in dilute urine and ↓ in concentrated urine • Presence of WBCs should cause careful consideration for the presence of bacteria and culture setup • Normal: Voided: 0–1/hpf • Neutrophils are the most common type of WBC seen • Nephritis, pyelonephritis, cystitis, urethritis, ureteritis Casts Casts, consisting of a mucoprotein matrix, are formed in the lumen of the distal and collecting tubules of the kidneys. Because of this location, they are all cylindrical with parallel sides and rounded to blunted ends. Cast morphology is susceptible to high-speed centrifugation, rough handling, and delayed analysis (degrade when allowed to sit in alkaline urine or for long periods). The presence of ↑ numbers of casts may indicate tubular disease, but the quantity does not suggest the duration or severity of disease. Epithelial • Color Plate 4.65 • Nearly transparent, clear, and highly refractile with renal epithelial cells • Originate from the Loop of Henle, distal tubule and collecting tubule • Never observed in normal urine • Nephrotoxicity, acute renal disease, ischemia, pyelonephritis Fatty • Color Plate 4.66 • Coarsely granular with fat droplets • Signify degeneration of the renal tubules • Diabetes mellitus and renal disease Granular • Color Plate 4.67 • Coarse to finely granular • Orange: bilirubin • Pink to red: hemoglobin or myoglobin • Composed of particulate matter from renal tubular cell necrosis or degeneration • Hyaline casts containing granules • Normal to see 0–2/hpf • Acute renal disease Hyaline • Color Plate 4.68 • • • • • Composed of pure protein precipitates (mucoprotein matrix) • Normal to see 0–2/hpf • Fever, mild renal disease, general anesthesia, IV diuresis, strenuous exercise RBC/WBC • Color Plate 4.69 • Color Plate 4.70 • RBC: • Contains a few to many RBCs • Deep yellow to orange • WBC: • Contains a few to many WBCs • Appearance changes to granular once the cells start to degenerate • Formed from the aggregation of RBCs and/ or WBCs • Never observed in normal urine • Intrarenal bleeding or infection, trauma, glomerulonephritis, renal tubulointerstitial inflammation, toxicity Waxy • Color Plate 4.71 • Highly refractile, homogeneous, and translucent • Blunted ends and cracks • Final stage of granular cast degeneration • Most stable of all casts • Chronic renal disease 152 Nearly transparent, clear and highly refractile Rounded ends Stained: light pink to purple May contain a few inclusions SECTION THREE: DIAGNOSTIC SKILLS Table 4.26 / Sediment Examination (Continued) Component Appearance Definition Associated Conditions Crystals Crystalluria may or may not be indicative of a medical condition. Crystals may form because of sample handling (e.g., refrigeration) or through the accumulation of normal urine components. Urine pH, concentration, temperature, and solubility of the components all contributes to the type of crystal formed. Crystals can be reported as occasional, moderate, many or by using a 1–4+ scale. Amorphous Phosphate • Color Plate 4.59 • Color Plate 4.72 • Granular precipitate • Dull brown in color • Typically seen in neutral or alkaline urine • Seen in normal urine • Easily confused with bacteria • Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog) Amorphous Urate • Color Plate 4.73 • Granular precipitate (sodium, potassium, magnesium and calcium salts) • Yellow or yellow-brown in color • Typically seen in acidic urine • Dissolve in alkaline urine • Easily confused with bacteria • Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog) Ammonium Biurate • Color Plate 4.74 • Round with long spicules • Resemble a thorn apple • Yellow to brown in color • Seen in alkaline, neutral or slightly acidic urine • Liver disease, portosystemic shunts, urate urolithiasis, or breed predisposed (Dalmatian and English Bulldog) Bilirubin • Color Plate 4.75 • Fine elongated spicules • Red brown or golden yellow in color • May be seen in normal urine • Liver disease or hemolytic anemia Calcium Carbonate • Color Plate 4.76 • Round with lines radiating out from the center • May resemble short dumbbells • Typically seen in alkaline urine • N/A Calcium Oxalate Dihydrate • Color Plate 4.77 • Colorless, square with refractile lines forming an × across the surface (e.g., envelopes) • Radiopaque with hard, sharp protrusions • +/− Cuboid shape • Typically seen in neutral or acidic urine • May be seen in normal urine • Ethylene glycol toxicity, oxalate urolithiasis Calcium Oxalate Monohydrate • Small, flat, elongated structures with pointed ends (e.g., spindles) • Typically seen in neutral or acidic urine • Ethylene glycol toxicity, oxalate urolithiasis Cystine • Color Plate 4.78 • Hexagon and flat • May appear as singles or in layers • Typically seen in acidic urine • Renal tubular dysfunction Leucine • Color Plate 4.79 • Yellow or brown, round with concentric striations • Typically seen in acidic urine • Not well understood • Acute liver disease or chloroform or phosphorus toxicity Sulfonamide • Color Plate 4.80 • Clear to brown, eccentrically bound needles in sheaves • Rarely seen with the newer forms of sulfonamide drugs • Sulfonamide treatment Triple Phosphate (Struvite, Magnesium, Ammonium and Phosphate, MAPS) • Color Plate 4.81 • 8-sided prisms with tapered sides and ends • Resemble coffin lids • ↑ Ammonia leads to fern leaf like appearance • Typically seen in neutral or alkaline urine • Cystitis or struvite urolithiasis CHAPTER 4 / LABORATORY 153 4 Table 4.26 / Sediment Examination (Continued) 4 Component Appearance Definition Associated Conditions Tyrosine • Color Plate 4.82 • Colorless or yellow, very fine needles in sheaves or clusters • Typically seen in acidic urine • Not well understood • Acute liver disease or chloroform or phosphorus toxicity Uric Acid • Color Plate 4.83 • Yellow brown diamond, rosettes, or oval plates with pointed ends • Typically seen in acidic urine • Liver disease, portosystemic shunts, or breed predisposed (Dalmatian and English Bulldog) Epithelial Cells Squamous and transitional epithelial cells are seen commonly in the urine of normal animals. Squamous epithelial cells are the largest of the epithelial cells and are considered not significant. Transitional epithelial cells only prove to be significant with a large increase in number. Renal epithelial cells, however, are typically only seen with renal disease and always thought to be significant. They are the smallest of the epithelial cells and are often confused with WBCs. Renal • Color Plate 4.84 • Round to caudate with a large eccentric nucleus displaced near the bottom • Prominent nucleolus • Often confused with WBCs • Epithelial cells originating from the renal tubules • Rarely found and usually indicate renal disease • Renal disease Squamous • Color Plate 4.85 • Very large, thin, and polygonal • Tend to fold onto themselves and appear singularly or in sheets • Small, round nucleus, placed close to the center • Appears as a fried egg • Epithelial cells originating from the urethra, bladder, vagina, and prepuce • Often seen and typically not significant • N/A Transitional • Color Plate 4.86 • Round to caudate, granular with a small nucleus centrally located • Varying size • Epithelial cells originating from the prokimal urethra, bladder, ureters, and renal pelvis • Often seen and only significant in large numbers, clumps or sheets • Cystitis, pyelonephritis, or neoplasia Miscellaneous Numerous artifacts can be seen in urine because of contamination. The following also can be seen with a disease condition associated with the urinary tract. Hemoglobin • Orange globules with varying size • Intravascular hemolysis resulting in free hemoglobin • Often confused with RBCs • Severe hemolytic diseases or alkaline urine Lipid Droplets • Color Plate 4.87 • Varying size, round, light green, and highly refractile • Seen in the plane of field just below the coverslip • Commonly seen in urine associated with no disease condition • Often confused with RBCs • Diabetes mellitus, obesity, and hypothyroidism Mucus Threads • Resemble twisting ribbons • More commonly seen after catheterization • May be seen in normal animals • Urethral irritation or genital 154 SECTION THREE: DIAGNOSTIC SKILLS Table 4.26 / Sediment Examination (Continued) Component Appearance Definition Associated Conditions Parasites Two urinary tract parasites can be seen in the dog and cat. Fecal contamination may lead to finding an array of parasites in urine, but the following are the only ones that originate from the bladder. Capillaria Plica • Color Plate 4.88 • Clear to yellow with flattened bipolar end plugs and a roughened shell • Bladder worm of dogs and cats • Travels through the lungs and may cause coughing • Nonpathogenic Dioctophyma Renale • Barrel shaped, bipolar, yellow brown with a pitted shell • Giant kidney worm of the dog • Largest nematode affecting domestic animals • Ingest the parenchyma of the right kidney, leaving only the capsule • Crayfish and fish are the intermediate host. • Kidney disease or peritonitis Urine Artifacts Many substances can contaminate a urine sample. They may arise from improper collection, the environment, or general anatomy. Besides the arti- 4 facts listed below, parasite eggs, fecal material, fungal spores, and fungi also may be seen. Please refer to the respective sections for identification of these items. Table 4.27 / Urine Artifacts Urine Artifact Appearance Definition Air Bubbles • Color Plate 4.78 • Varying size, round, flat, refractile with a dark border • Result from the trapping of air during the application of the cover slip Fungi • Aseptae or segmented hyphae • Contaminant • Patients with systemic fungal disease affecting the urinary system (rare) Hair • Needle like with tapered edges • Contaminant from environment or surrounding genitalia Pollen • Double budding spores (e.g., Mickey Mouse®) • Contaminant from environment Sperm • Oval head with a whip like tail • Seen in the urine of intact males or recently mated females Starch Granules • Color Plate 4.89 • Faceted or scallop edges with indented or dimpled center • Not refractile • Contaminant from gloves Yeast • Color Plate 4.90 • Oblong, colorless budding bodies with double refractile walls • Varying size • Contaminant from environment or surrounding genitalia • Certain species may infect the urinary tract of patients with resistant UTI (rare) Note: The normal values for this chapter are used with permission from Phoenix Central Laboratory. CHAPTER 4 / LABORATORY 155 Chapter 5 Imaging Radiology 159 Radiographic Equipment 160 Radiographic Exposure and Image Factors 161 Radiographic Technique Chart 161 Example 1: Veterinary X-Ray Technique Guide 162 Example 2: Veterinary X-Ray Technique Chart 163 Evaluating Radiograph Technique 164 Exposure Evaluation 164 Density Evaluation 164 Scale of Contrast Evaluation 164 Radiographic Alterations 166 Radiographic Artifacts 167 Radiographic Positioning 167 Directional Terms 168 Positional Terms 168 Soft Tissue Positioning 169 Thorax 169 Abdomen and Pharynx 169 Head Positioning 170 Skull 170 Zygomatic Arch 171 Tympanic Bullae 172 Temporomandibular Joint 172 Nasal Cavities and Sinuses 173 Nasal Cavities and Sinuses (continued) Spine Positioning 174 Cervical 174 Thoracic–Lumbar 175 Sacrum–Caudal 175 Shoulder and Forelimb Positioning 176 Scapula–Shoulder 176 Humerus 176 Elbow 177 Radius/Ulna and Carpus 178 Metacarpus/Phalanges 178 Pelvis and Hindlimb Positioning 179 Pelvis 179 Femur, Stifles, and Tibia/Fibula 180 Tarsus and Metatarsals 181 Radiographic Contrast Studies 181 Types of Contrast Media 182 Fistula Contrast Studies 183 5 173 157 c05.indd 157 3/14/2008 11:49:10 AM Fistulography 183 Abdominal Contrast Studies 183 Peritoneography 183 Gastrointestinal Tract Contrast Studies 184 Esophagography and Gastrography 184 Upper and Lower Gastrointestinal Study 185 Head Contrast Studies 187 Dacryocystorhinography, Rhinography, and Sialography 187 Spinal and Joint Contrast Studies 188 Myelography and Epidurography 188 Discography and Arthrography 189 Urethra Contrast Studies 190 Urethrography, Canine 190 5 158 c05.indd 158 Urethrography, Feline 191 Vaginal Contrast Studies 192 Vaginography 192 Urinary Tract Contrast Studies 193 Cystography 193 Cystography (continued) 194 Additional Imaging Techniques 195 Computer Tomography and Echocardiography 195 Fluoroscopy 196 Magnetic Resonance Imaging and Nuclear Medicine Ultrasonography 197 Basic Scanning Technique 198 Sites for Ultrasound Scanning 198 196 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:10 AM a Key Words and Termsa Abbreviations Collimate Commissure Computer radiography Contrast Density Dosimeter Hypertonic Manubrium Mucoceles Radiolucent Radiopaque Retrograde Santes’ rule Stranguria Transaxially C, cranial Cd, caudal CHF, congestive heart failure CMIARF, contrast medium–induced acute renal failure CRT, capillary refill time CSF, cerebral spinal fluid CT, computed tomography D, dorsal Di, distal DR, digital radiography DV, dorsoventral EU, excretory urography FFD, focal film distance GIT, gastrointestinal tract IP, image plate IVP, intravenous pyelography IVU, intravenous urography kVp, kilovoltage peak Additional Resources, page L, lateral LAT, lateral M, medial mA, milliamperage mA-s, milliamperage per second MHz, megahertz MM, mucous membranes MRI, magnetic resonance imaging OBL, oblique Pa, palmar Pl, plantar Pr, proxmial R, rostral s, seconds SID, source image distance V, ventral VD, ventrodorsal Anatomy, 3 Anesthesia, 439 Catheter Placement, 349 Fluid Therapy, 359 General Medicine, 201 Injections, 348 Medical Procedures, 427 Monitoring, 332 Stomach Tube Placement, 428 Urinary Catheter Placement, 435 5 Key words and terms are defined in the glossary on page 631 RADIOLOGY Radiographs are an extremely useful diagnostic tool for the veterinarian. However, to be diagnostic, the radiograph must reflect proper measurement and positioning of the patient. Veterinary technicians are a valuable resource in the production of these radiographs. An understanding of the anatomic layout of the species and the manner in which a radiograph is taken is of great assistance to the production of a diagnostic radiograph. This chapter contains the basic information of radiographic equipment, imaging factors, positioning information, and contrast radiography. Digital radiography (DR) has made its way into the veterinary field. This technology complements the advancements made in computer technology and results in many benefits for the patient, veterinarian, and staff. The advantages to DR include increased time efficiency in processing, storing and retrieving of radiographs, improved contrast resolution allowing soft tissue and bone evaluation in one image, and the ability to use teleradiology. There is also the ability to change the contrast and density of the image to improve diagnostic sensitivity, but this technique can also add artifacts leading to confusion and misdiagnosis. With the expected decrease in the number of retakes due to computer manipulation and the increased efficiency of the DR unit, patient and staff safety should increase. CHAPTER 5 / IMAGING c05.indd 159 159 3/14/2008 11:49:10 AM Table 5.1 / Radiographic Equipment Radiographic equipment is especially expensive and extreme care should be taken with its use and maintenance. However, the greatest risk with radiography is patient and staff safety. It has been scientifically proven that ionizing radiation causes damage to living cells (e.g., reproductive, growth, gonadal, cancer, metabolically active cells). There is no level of exposure that is nondamaging; therefore, caution should be taken to limit exposure to the lowest level possible. Protective apparel is the first defense against radiation exposure—lead aprons, thyroid shields, and gloves must be worn in all circumstances. The staff should also protect themselves by wearing a dosimeter badge and goggles and by staying as far back from the primary beam and subsequent scatter radiation as possible. Excessive and unnecessary exposure should also be avoided. Equipment Description Maintenance Protective Apparel • • • • • Hang aprons vertically or lay flat. • Gloves should be placed on vertical holders or over bottomless soup cans to allow airflow and avoid cracks in the lead lining. • Radiograph all apparel quarterly to assess protectiveness of shield and check for cracks, tears, or other irregularities. 5 Aprons Thyroid shields Gloves Dosimeter Film-Screen Radiography Processing Tanks • Develops the film • May be manual or automatic • Clean routinely, and replenish liquids as needed. • Clean thoroughly every 2–3 months. • Check manufacturer’s guidelines for your specific machine. Film • Imprints the image (various types) • Handle carefully. • Store in a vertical position in a cool, dry, dark place. Cassettes • Houses the film and intensifying screens • Do not drop or allow leaking liquids into the cassette. • Clean the exterior regularly with mild soap and water. • Clean the intensifying screens routinely with a commercial solution, mild soap and water, or dilute ethyl alcohol. • Leave the cassette open and propped in a vertical position to dry. • Store in a vertical position when loaded with film. Computed Radiography Reader • Reads the image from the IP Image Plate (IP) • Imprints the image Computer • Manipulates and permits viewing of the image • Erase the plates daily. • Clean the plates once a week. Direct Digital Radiography Selenium Detector Plate 160 c05.indd 160 • Utilizes a direct energy conversion process to capture image • Offset calibration daily. SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:11 AM Table 5.2 / Radiographic Exposure and Image Factors Factor Definition Application Contrast • The difference between the lightest and darkest part of the film, reflecting 2 adjacent radiographic densities • High kVp (low contrast) for tissue • Low kVp (high contrast) for bone Density • The degree of blackness of a film • To produce a darker film ↑ mA, kVp, or exposure time Detail • The clarity of the image on the film • For better detail: use longer source–image distance (SID), have the patient closer to the film, and use a shorter exposure time. Distortion • The alteration of the original image • For less distortion: use short SID, have the patient closer to the film, and less angulation of the film or patient. Exposure Time (s) • Measures the length of time electrons are allowed to flow across the tube • Longer exposure time = ↑ production of x-rays • mA-s is the product of milliamperage and the exposure time. It indicates the number of x-rays being produced during an exposure. • Using a high mA setting allows for the use of shorter exposure times. Grid Factor • The ↑ in exposure to compensate absorption by the grid device • Used in the formation of a technique chart (part of Santes’ rule) Kilovoltage peak (kVp) • Measurement of the electric potential difference between the cathode and anode in the x-ray tube • Higher kVp = greater penetration power • Controls the quality • Directly proportional to film density and inversely proportional to film contrast Milliamperage (mA) • Measurement of the number of electrons that flow across the tube from cathode to anode • Higher mA = production of more x-rays • Directly proportional to film density Milliamperage per Second (mA-s) • The number of x-rays produced per second • Controls the number and quantity of x-rays produced Source Image Distance (SID) • Focal spot to film distance (FFD) • The distance between the focal spot on the target anode and the radiographic film • ↑ SID = a ↓ in the number of x-rays reaching the film Radiographic Technique Chart Every clinic with an x-ray machine should have a technique chart that has been assessed by the local radiologist to fit your particular machine. These charts significantly decrease the time involved in the calculation of the machine settings and thereby reduce the time spent on taking each radiograph. The chart also ensures consistency among the personnel using the machine. Factors involved in a technique chart are the species, the anatomic region, the x-ray machine, screen type, and the film type. The basic steps to set up a technique chart are: 1. Choose an animal of respective size to reflect its species (e.g., canine: an animal around 50 pounds; feline: an animal around 9 pounds). 2. Measure the animal laterally around the thickest part of the thorax. Set standard SID as a constant (40). 3. Calculate the kVp requirement using Santes’ rule: (2 × tissue thickness in cm) + SID + grid factor = kVp. • Example: (2 × 15 cm) + 40 + 8 = 78 kVp 4. Determine mA-s requirement based on the following chart: CHAPTER 5 / IMAGING c05.indd 161 5 161 3/14/2008 11:49:11 AM Fast/High-Speed Screens Average Dog Medium/Par Speed Screens MA-s Anatomical Region mA-s 2.5 Extremity 5.0 5.0 Thorax 7.5 7.5 Abdomen 10.0 10.0 Pelvis 12.5 Average cat: mA-s is recommended at 1.5. 5 5. Determine the mA and exposure time with emphasis on the highest mA possible. Divide mA by mA-s to get exposure time (seconds). 1 Example: 300 divided by 5.0 = –60 6. Take a trial radiograph of the animal, using the calculated factors and assess its quality. Modify the mA-s by 30–50% in the appropriate direction and retake the radiograph. 7. Once a diagnostic radiograph is produced, use these factor numbers to start your chart. This will need to be repeated for the various areas of the body and for each species. See guidelines below for the chart making: For each 1-cm change, add or subtract 2 kVp, up to 80 kVp. For each 1-cm change, add or subtract 3 kVp, from 80–100 kVp. For each 1-cm change, add or subtract 4 kVp, above 100 kVp. 8. Modifications to this method would include: a. Pleural fluid or ascites or obvious organ enlargement (e.g., cardiomegaly) (↑ mA-s 50%) b. Obesity, heavily muscled dogs, or contrast studies (↑ mA-s 50%) c. Excessively thin animals or puppies/kittens (↓ mA-s by 50%) The following charts reflect 2 different styles of a technique chart. It is helpful to have your chart reviewed by a board-certified radiologist. Example 1: Veterinary X-Ray Technique Chart The following is for use with: QUANTA 3 screens SID is 40″. Grid ratio is 8:1 CRONEX 7 film Kodak LANEX REGULAR Kodak TMG-1 film mA Time mA-s kVp Skull 3.3 (2 × cm) + 55 kVp 1/60 5 (2 × cm) + 55 kVp 300 1/60 5 (2 × cm) + 50 kVp 300 1/30 10 (2 × cm) + 48 kVp Small Dogs and Cats 300 Medium and Large Dogs 300 Small Dogs and Cats Medium and Large Dogs Cervical Thorax 3.3 (2 × cm) + 43 kVp 1/60 5 (2 × cm) + 43 kVp 300 1/60 5 (2 × cm) + 45 kVp 300 1/30 10 (2 × cm) + 50 kVp Small Dogs and Cats 300 1/60 5 (2 × cm) + 52 kVp Medium and Large Dogs 300 1/30 10 (2 × cm) + 52 kVp Extra-Large Dogs 300 1/30 10 (2 × cm) + 60 kVp Small Dogs and Cats 300 Medium and Large Dogs 300 Small Dogs and Cats Medium and Large Dogs Abdomen and Thoracic Spine Pelvis Extremities: Femur and Humerus Small Dogs and Cats 300 1/45 Medium and Large Dogs 300 1/30 Small Dogs and Cats 300 1/45 Medium and Large Dogs 300 1/30 6.6 10 (2 × cm) + 45 kVp (2 × cm) + 45 kVp Extremities: Radius and Ulna 162 c05.indd 162 6.6 10 (2 × cm) + 45 kVp (2 × cm) + 45 kVp SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:11 AM Example 2: Veterinary X-Ray Technique Chart Bone 300 mA Chest 300 mA kVp Abdomen 300 mA kVp kVp cm Time Table Grid Time Table Grid Time Table Grid 4 1/30 42 — 1/60 44 — 1/30 — — 5 “ “ — “ 46 — “ — — 6 “ 45 — “ 48 — “ — — 7 “ “ 55 “ 50 — “ — — 8 “ “ 57 “ 52 — 1/15 — 51 9 “ 46 59 “ 54 — “ — 53 10 “ “ 61 “ 56 — “ — 55 11 “ — 63 “ 58 — “ — 57 12 “ — 65 “ 60 74 “ — 59 13 “ — 67 “ 62 76 “ — 61 14 “ — 69 “ 64 78 “ — 63 15 “ — 71 “ 66 80 “ — 65 16 “ — 73 “ 68 82 “ — 67 17 “ — 75 “ — 85 “ — 69 18 “ — 77 “ — 88 “ — 71 19 “ — 79 “ — 91 “ — 73 20 “ — 81 “ — 95 “ — 75 21 “ — 84 “ — 99 “ — 77 22 “ — 87 “ — 103 “ — 79 23 “ — 90 “ — 103 “ — 82 24 “ — 94 1/30 — 96 “ — 85 25 “ — 96 “ — 100 “ — 88 26 “ — 103 “ — 105 “ — 91 27 “ — 108 “ — 110 “ — 95 5 “ Indicates same value as above; —, not applicable. CHAPTER 5 / IMAGING c05.indd 163 163 3/14/2008 11:49:11 AM Evaluating Radiograph Technique Density Evaluation Following a technique chart to take a radiograph is a straightforward process. However, this still may not produce a radiograph with the contrast and density needed for a quality image. There are many factors that affect the quality of the film; besides equipment issues, the mA, kVp, and time have considerable control of image quality. Understanding their relationship along with the difference based on BCS, breed, and disease condition can produce the desired quality of radiograph. The density of a film is the degree of blackness and is mostly controlled by mA-s. Begin evaluating the density by determining the degree of blackness. The area outside the patient’s body and inside the collimated area should be black. Lighter shades would indicate ↑ density is needed. Table 5.3 / Exposure Evaluation 5 To determine if an x-ray needs to be adjusted, one must first be able to evaluate the quality of a film. There are some basic guidelines to a properly exposed image, but there is also veterinarian preference. Begin by evaluating the overall appearance (e.g., too light or too dark) of the x-ray. With the xray on a standard viewing box, place your hand under the image. If you are able to see your fingers, yet not the wrinkles and creases the image has the correct exposure. If you are not able to see your fingers, the image is overexposed (too dark) and if you can see your fingers and all wrinkles and creases the image is underexposed (too light). If it is determined that an image is too light or too dark, further evaluations need to take place to determine why. Underexposed (Too Light) Good Exposure Overexposed (Too Dark) Hand Test • Fingers, wrinkles, and creases visible • Fingers visible • Fingers not visible Thorax • Visible: surrounding vasculature • Not visible: vasculature over the heart, lung over diaphragm • Visible: caudal vena cava, descending aorta, bronchi, pulmonary vessels, cardiac silhouette, air-filled lungs • Taken on inspiration • Optimal: high kVp and low mA-s (↑ contrast and ↓ density) • Lungs are as black as the background. Abdomen • Internal organs are washed out and not distinguishable. • Visible: margins of the internal organs, stomach, diaphragm, small and large intestines, liver, spleen, bladder, ± kidneys, prostate • Taken on expiration • Optimal: low kVp and high mA-s (↑ density and ↑ contrast) • Internal organs are dark and not distinguishable. • Clear margins of compact bone with a radiolucent center, physes in young animals (can be open up to 14 months) • Optimal: low kVp and high mA-s (↑ density and ↑ contrast) • Bone is bright white with no detail. Bony Structures • Bone is dark with no detail. Eraluating Radiograph Technique Table 5.4 / Scale of Contrast Evaluation The scale of contrast is the shades of grays or the degree of blacks and whites and is mostly controlled by kVp. A kVp setting that is too high will give a low contrast (e.g., overall gray appearance). A kVp setting that is too low will give a high contrast (e.g., strong blacks and whites). Once a radiograph has been evaluated and it is determined that alterations are needed, the decision needs to be made as to what settings need to be altered. Unfortunately, this is not an exact science and adjustments of one or more settings may be needed. However, there are some general starting points when adjusting the settings. In general, mA-s is altered by 25–50% to make large overall changes and to alter the density (degree of blackness). kVp is altered by 10–15% to make small subtle changes and alter the scale of contrast. Another point, altering the kVp by 10–15% is approximately the same change in exposure as altering the mA-s by 50% (e.g., halving or doubling the mA-s). Therefore, with proper exposure and the need to only change the contrast, the kVp and mA-s must be altered together in the opposite direction (e.g., ↑ kVp and ↓ mA-s). 164 c05.indd 164 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:11 AM Table 5.4 / Scale of Contrast Evaluation (Continued) Alteration ↑ Density • Film is too dark. • ↓ mA-s • To ↓ the amount of x-rays and ↓ the blackness ↓ Density • Film is too light. • ↑ mA-s • To ↑ the amount of x-rays and ↑ the blackness ↑ Contrast • Film has strong blacks and whites. • ↑ kVp • To ↑ the penetrating power of the x-rays and to lengthen the scale of contrast ↓ Contrast • Film is washed out/gray appearance. • ↓ kVp • To ↓ the penetrating power of the x-rays and to shorten the scale of contrast Example 5 Film Evaluation 165 c05.indd 165 3/14/2008 11:49:11 AM Table 5.5 / Radiographic Alterations BCS With radiology experience, adjustments to the mA-s and kVp can be made prior to the first x-ray taken. There are certain anatomical factors (e.g., body weight, muscle mass, haircoat) that are known to alter the image based on the technique chart. The technique chart is based on an “average” animal and alteration for normal often requires setting adjustments. The most important point to remember is that large changes are made with mA-s (25–50%) and subtle changes are made with kVp (10–15%). Disease Breed and Anatomy 5 166 c05.indd 166 Evaluation Radiograph Effect Setting Alteration Comments BCS 1–2 • ↓ Body fat, muscle wasting • ↓ mA-s and/or kVp • ↓ Subject density BCS 4–5 • ↑ Body fat • ↑ mA-s and/or kVp • ↑ Subject density Achondroplastic dwarf • Compressed mediastinal area • Short dense legs • ↑ mA-s and/or kVp • ↑ Subject density • Be sure legs are pulled out of the view (e.g., tape stirrups). Barrel-chested • ↑ Thoracic size • ↑ mA-s • ↑ Subject density • Extend cervical region as far forward as possible. Brachycephalics • Motion artifact • Trapped air • X-rays not taken on inspiration/expiration • ↓ mA-s and/or kVp to ↓ density • Blow in their nose to briefly stop panting. Deep-chested • Deep cranial thorax and thin caudal thorax • ↓ mA-s and/or kVp • Two views may need to be taken to achieve proper exposure in both regions. • Ensure proper positioning of VD images (e.g., supportive devices) to avoid oblique images. Giant breeds • ↑ Overall size • ↑ mA-s • ↑ Subject density • Divide the area into 2 sections (e.g., cranial and caudal thorax) to view entire area. Haircoat • Excessive amount or mats • Debris and foreign bodies • ↑ kVp • ↑ Subject density • Move excessive hair out of view if possible. • Foreign bodies found on the image should be verified they are not within the haircoat. Muscle • ↑ Muscle mass • ↑ mA-s and/or kVp • ↑ Subject density • Ensure proper positioning of VD images (e.g., supportive devices) to avoid oblique images. Skin • ↑ Skin folds • ↑ mA-s and/or kVp • ↑ Subject density • Pull skin folds out of view if possible. Any condition resulting in: • Ascites/edema • ↑ mA-s and ± ↓ kVp • ↑ kVp along with free fluid = ↑ scatter • Free air • ↓ mA-s and/or kVp • ↓ Subject density • Foreign bodies • ± mA-s and kVp alterations • Adjustments are made based on the opacity of the item. • Soft tissue swelling • ↑ mA-s and/or kVp • ↑ Subject density SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:12 AM Table 5.6 / Radiographic Artifacts Problems Seen on Radiograph Artifact Solution Blurred images • Motion • Double exposure • Proper positioning and handling of animal • Double-check cassette tray for foreign objects Clear areas on the sides of the radiograph • Film fog • Mislocation of beam to film • Proper handling of film • Verification that the beam and cassette are aligned Dark line with mirror image of object • Film folded on itself • Proper loading of cassette Dark semicircle impression • Finger pressure mark • Proper handling of film Dark striations (sea lichen or dotted) • Static electricity • Proper handling of film Gray streaks • Wet animal fur • Clean off and dry animal Lines or objects visualized outside/inside the animal’s body that are unexplainable • Foreign objects in or on the cassette (hair, paper, etc.) • Proper cleaning of cassette • Proper handling of film Hardwood flooring • Plank floor • ↓ mA-s White lines across the film • Scratches on the film • Proper handling of film Radiographic Positioning The most important factor in positioning a patient for radiographs is to have a mental vision of the part of the body to be radiographed and a good understanding of its anatomic placement. A second important factor is to use supports to ensure that the patient is aligned properly and to decrease the operator’s exposure. These supports can include sandbags, 5 nonradiopaque wedges, nonradiopaque “V” troughs, gauze, and tape. Depending on the species, size, and condition of the animal being radiographed, the following positioning guidelines may need to be adjusted accordingly. Understanding directional terminology is critical to the proper positioning of every radiograph. Specific anatomical landmarks are identified in Chapter 1: Anatomy. CHAPTER 5 / IMAGING c05.indd 167 167 3/14/2008 11:49:12 AM Table 5.7 / Directional Terms 5 Directional Term Definition Dorsal (D) • Any given point toward the back Ventral (V) • Any given point toward the lower area of the thorax and abdomen, closest to the ground Cranial (C) • Any given point toward the head • The area above the carpal and tarsal joints on the limbs toward the head Caudal (Cd) • Any given point toward the tail • The area above the carpal and tarsal joints on the limbs toward the tail Rostral (R) • Any given point on the head toward the nose Proximal (Pr) • Any given point nearest the point of origin or attachment Distal (Di) • Any given point farthest away from the point of origin or attachment Medial (M) • An area near the midline • The inside aspect of the limbs Lateral (L, Lat) • An area situated away form or opposite the midline • The outside aspect of the limbs Palmar (Pa) • Caudal portion of the forelimb distal to the carpal joint Plantar (Pl) • Caudal portion of the hindlimb distal to the tarsal joint Positioning Terms The patient is positioned so as the x-ray beam enters and exits based on the positional term. For example: caudocranial allows the x-ray beam to enter in the caudal aspect and exit the cranial aspect of a given anatomical region. Dorsalventral (DV) Ventrodorsal (VD) Dorsopalmar (DPa) Palmarodorsal (PaD) Dorsoplantar (DPl) Plantarodorsal (PlD) Additional Examples: Recumbent: The patient is positioned on their side, left or right. Caudocranial (CdC) Craniocaudal (CCd) Oblique (Obl): The patient is placed in a slanted or inclined position so that the x-ray beam will enter the body at an angle. 168 c05.indd 168 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:12 AM Soft Tissue Positioning Skill Box 5.1 / Soft Tissue Positioning: Thorax Anatomic Area Thorax View Lateral V/D D/V Positioning • • • • • Dorsal recumbency • Forelimbs extended cranially • Hindlimbs flexed • Sternal recumbency • Forelimbs extended caudally and elbows abducted • Head lies low between forelimbs • Rear limbs in crouching position Left lateral recumbency (heart assessment) Right lateral recumbency (lung assessment) Forelimbs and head extended cranially Rear limbs extended caudally Measurement • Widest area of ribcage • Widest area of ribcage • Widest area of ribcage Beam Center • Caudal border of scapula • Caudal border of scapula (6th rib) • Caudal border of scapula (6th rib) Field of View • Thoracic inlet to the last rib • Thoracic inlet to the last rib • Thoracic inlet to the last rib Notes • Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • May require support (e.g., wedges) to keep sternum inline with the thoracic vertebrae • Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • Restraining the animal at the scapula/armpits results in a straighter thorax. • Taken on peak inspiration • If pneumothorax is suspected, expiratory radiographs also may be required. • Preferred view for cardiac evaluation or for animal in respiratory stress 5 Skill Box 5.2 / Soft Tissue Positioning: Abdomen and Pharynx Anatomic Area Abdomen Pharynx View Lateral V/D Lateral Positioning • Right lateral recumbency • Forelimbs extended cranially • Hindlimbs extended caudally • Dorsal recumbency • Forelimbs extended cranially and parallel • Lateral recumbency • Forelimbs flexed caudally • Head should be parallel to the table (may require support) and neck extended. Measurement • Caudal aspect of the 13th rib or widest area • Hindlimbs extended caudally and parallel • Base of the skull Beam Center • Caudal aspect of the 13th rib • Caudal aspect of the 13th rib or widest area • Just caudal the base of the skull Field of View • 2–3 inches cranial to xyphoid process of sternum to the femoral head • Caudal aspect of the 13th rib • Lateral canthus to C3 Notes • Taken on expiratory pause • A left lateral may also be requested. • Two films may be needed with large dogs. • Taken on expiratory pause • Two films may be needed with large dogs. CHAPTER 5 / IMAGING c05.indd 169 169 3/14/2008 11:49:12 AM Head Positioning Ensuring that the skull is level to the cassette is extremely important in producing a diagnostic radiograph. Supports strategically placed under the muzzle, neck, or cranium will assist. Skill Box 5.3 / Head Positioning: Skull 5 Anatomic Area Skull View Lateral D/V V/D Cranium—Rostrocaudal Positioning • Lateral recumbency • Foam wedge placed under mandible to make muzzle parallel • Nasal septum parallel to cassette • Forelimbs extended caudally • Sternal recumbency • Head is parallel to the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam. • Dorsal recumbency • Head is extended on cassette with support under the mid-cervical region to keep proper alignment. • Nose is parallel to cassette. • Skull is level on the cassette. • Forelimbs extended caudally • Dorsal recumbency • Base of skull is resting on cassette with neck in a flexed position and the chin pulled toward the thorax with tape or gauze. • Forelimbs extended caudally Measurement • Highest point of zygomatic arch • Widest point of cranium • Lateral canthus of eye • Frontal sinuses Beam Center • Lateral canthus of eye • Lateral canthus of eye • Lateral canthus of eye • Between the eyes Field of View • Tip of nose to base of skull • Tip of nose to base of skull • Tip of nose to base of skull • Entire cranium Notes • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • Monitor for crimping if endotracheal tube is in place. 170 c05.indd 170 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:12 AM Skill Box 5.4 / Head Positioning: Zygomatic Arch Anatomic Area Zygomatic Arch View Lateral D/V Frontal Lateral Oblique V/D Open Mouth Positioning • Lateral recumbency • Foam wedge placed under mandible • Nasal septum parallel to cassette • Forelimbs extended caudally • Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam. • Dorsal recumbency • Head is resting on cassette with neck in a relaxed flexed position. • Nose is slightly off perpendicular to x-ray beam. • Skull is level on the cassette. • Forelimbs extended caudally • Lateral recumbency • Cranium supported with wedge to achieve the oblique angle of the arch • Nasal septum perpendicular to cassette • Dorsal recumbency • Head is extended with support under the midcervical region. • Mandible supported open using gauze • Skull is level on the cassette. • Forelimbs extended caudally Measurement • Highest point of zygomatic arch • Highest point of cranium • Lateral canthus of eye • Highest point of cranium • Lateral canthus of eye Beam Center • Lateral canthus of eye • Lateral canthus of eye • Lateral canthus of eye • Slight off center from mid-cranium • At a 45° angle to the maxilla between the upper 3rd and 4th premolars Field of View • Tip of nose to base of skull • Tip of nose to base of skull • Tip of nose to base of skull • Tip of nose to base of skull • Nasal cavities to cranial temporal skull Notes • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • May require heavy sedation or general anesthesia • Monitor for crimping if endotracheal tube is in place. CHAPTER 5 / IMAGING c05.indd 171 5 171 3/14/2008 11:49:12 AM Skill Box 5.5 / Head Positioning: Tympanic Bullae Anatomic Area 5 Tympanic Bullae View D/V Lateral Oblique Rostrocaudal: Open Mouth Positioning • Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam. • • • • • Dorsal recumbency • Nose is perpendicular to cassette with maxilla and mandible supported open. • Base of skull is level on the cassette. • Forelimbs extended caudally Measurement • Highest point of cranium • Level of tympanic bullae • Level of commissure of lips Beam Center • Center of tympanic bullae • Center of tympanic bullae • Center of mouth and between commissure of lips Field of View • Lateral canthus of eye to base of skull • Lateral canthus of eye to base of skull • Entire nasopharyngeal area Notes • Superimposition of cranium makes view of bullae less than ideal; however, it permits comparison of left and right bullae in 1 view. Lateral recumbency Unaffected bullae toward the cassette Skull slightly oblique Forelimbs slightly extended caudally Skill Box 5.6 / Head Positioning: Temporomandibular Joint Anatomic Area Temporomandibular Joint View D/V V/D Oblique (Sagittal Oblique) Positioning • Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam. • Lateral recumbency • Cranium rotated 20° toward the cassette (with support under mandible) Measurement • Highest point of cranium • Lateral canthus of eye Beam Center • Lateral canthus of eye • Temporomandibular joint Field of View • Base of the nose to the base of the skull • Medial canthus of eye to base of skull 172 c05.indd 172 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:12 AM Skill Box 5.7 / Head Positioning: Nasal Cavities and Sinuses Anatomic Area Nasal Cavities and Sinuses View Lateral D/V D/V: Occlusal Positioning • Lateral recumbency • Foam wedge placed under mandible to keep muzzle parallel to cassette • Nasal septum parallel to cassette • Forelimbs extended caudally • Sternal recumbency • Head is resting on the cassette. • Forelimbs are relaxed with carpus flexed and out of the beam. • • • • Measurement • Highest point of zygomatic arch • Highest point of cranium • Caudal portion of maxilla Beam Center • Lateral canthus of eye • Lateral canthus of eye • Caudal portion of maxilla Field of View • Tip of nose to base of skull • Tip of nose to commissure of lips • Tip of nose to orbital bones Notes Sternal recumbency Head is resting on the cassette. Film is between maxilla and mandible. Forelimbs are relaxed with carpus flexed and out of the beam. 5 • Best to use “cassette-less” film (e.g., mammography film) Skill Box 5.8 / Head Positioning: Nasal Cavities and Sinuses (continued) Anatomic Area Nasal Cavities and Sinuses View V/D Open Mouth Lateral Oblique Frontal or Rostrocaudal Positioning • Dorsal recumbency • Forelimbs extended caudally • Head is extended on cassette with support under the mid-cervical region. • Nose is parallel to cassette with mandible extended caudally with supports. • Maxilla may be taped into position if necessary. • Skull is level on the cassette. • Lateral recumbency • Head supported with wedge • Nasal septum perpendicular to cassette • Dorsal recumbency • Forelimbs extended caudally • Head is resting on cassette with neck in a relaxed flexed position and muzzle pointing up at the tube. • Nose is slightly off perpendicular to cassette (10°). • Skull is level on the cassette. Measurement • 3rd upper premolar • Highest point of cranium • Most caudal aspect of muzzle (nose stop) Beam Center • 15° from vertical with the beam angled into the open mouth between the upper 3rd and 4th premolars • Lateral canthus of eye • Between the eyes Field of View • Tip of nose to pharyngeal area • Tip of nose to base of skull • Tip of nose to base of skull Notes • Remove or tie endotracheal tube to mandible. • Same technique could be used to radiograph the foramen magnum. • Remove or tie endotracheal tube to mandible. CHAPTER 5 / IMAGING c05.indd 173 173 3/14/2008 11:49:12 AM Spine Positioning The spine must be kept level as films are taken. A misaligned spine will result in distortion on the radiograph and therefore possibly a nondiagnostic radiograph. Levelness can be accomplished with supports under the mandible, neck, or thorax or between the limbs. A “V” trough or wedges are recom- 5 mended on all ventrodorsal views to stabilize the body of the animal. Always collimate down to exclude the soft tissues. Most of these positions will require some form of sedation or general anesthesia. Abbreviations have been used to conserve space and are as follows: O = occipital, A = atlantal, C = cervical vertebra, T = thoracic vertebra, TL = thoracolumbar vertebra, L = lumbar vertebra, S = sacral vertebra Skill Box 5.9 / Spine Positioning: Cervical Anatomic Area Cervical View Lateral V/D Extended Lateral Flexed Lateral Oblique Lateral Positioning • Lateral recumbency • Forelimbs retracted caudally • O-A joint is flexed at a 45° angle. • Elevate the mandible to be parallel to table with support. • Gauze may be needed around the mouth to keep head pulled slightly forward. • Dorsal recumbency • Forelimbs extended caudally alongside the body • Spine parallel to cassette • Support under the neck can minimize distortion caused by a misaligned vertebra. • Lateral recumbency • Forelimbs extended caudally • Extend the neck dorsally until resistance is met; gauze may be placed around the muzzle • Place support under the mandible and neck to maintain a level spine (especially with longnecked dogs). • Lateral recumbency • Forelimbs extended caudally • O-A is flexed at a 90° angle. • Elevate the neck if necessary to keep it level with the spine (wedges). • Pull the lower mandible open with gauze to maintain the 90° angle. • Lateral recumbency • Elevate the mandible to be parallel to table with support (wedges). • Elevate the sternum 20° above vertebral level/plane with support (wedges). Measurement • Over C7 • C5–C6 • Thoracic inlet (C7) • Thoracic inlet (C7) • Thoracic inlet (C7) Beam Center • C4–C5 and vertebral column • C4–C5 and vertebral column • C4–C5 and vertebral column • C4–C5 and vertebral column • C4–C5 and vertebral column Field of View • Caudal skull to T1 • Caudal skull to T1–T2 • Caudal skull to T1–T2 • Caudal skull to T1–T2 • Caudal skull to T1–T2 Notes • Two films are recommended for large dogs. • Two films are recommended for large dogs. 174 c05.indd 174 • Be careful not to overflex the neck, as tracheal damage may occur. SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:12 AM Skill Box 5.10 / Spine Positioning: Thoracic–Lumbar Anatomic Area Thoracic Thoracolumbar Lumbar View Lateral V/D Lateral V/D Lateral V/D Positioning • Lateral recumbency • Forelimbs extended cranially • Hindlimbs extended caudally • Elevate sternum to thoracic vertebrae level to reduce rotational artifact. • Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position • Lateral recumbency • Forelimbs slightly extended cranially • Hindlimbs slightly extended caudally • Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position • Lateral recumbency • Forelimbs in a relaxed position • Hindlimbs extended caudally with support between them to keep hips parallel to the table • Dorsal recumbency • Forelimbs extended cranially • Hindlimbs in a relaxed position Measurement • 7th–8th rib • Highest point of the sternum • TL junction • TL junction • Thickest area (L1) • Thickest area (L1) Beam Center • T6–T7 • T6–T7 (caudal border of scapula) • TL junction • TL junction • L4 • L4 Field of View • C7–L1 • C7–L1 • T8–L5 • T8–L5 • T13–S1 • T13–S1 5 Notes • May require support under sternum and midlumbar region for proper alignment and prevention of axial rotation artifact (especially in chondrodystrophic dogs with elongated backs) • May require support under sternum and midlumbar region for prevention of axial rotation artifact Skill Box 5.11 / Spine Positioning: Sacrum—Caudal Anatomic Area Sacrum Caudal View Lateral V/D Lateral V/D Positioning • Lateral recumbency • Hindlimbs are slightly apart and relaxed with a support between them. • Tail is extended caudally, not supported. • Dorsal recumbency • Hindlimbs are relaxed in semiflexion. • Lateral recumbency • Tail is extended caudally and supported as needed to prevent excessive sagging or lateral flexion. • Dorsal recumbency • Hindlimbs are relaxed in semiflexion. • Tail is extended straight caudally and supported as needed to prevent excessive sagging or lateral flexion. Measurement • Trochanters • Mid-sacrum • Area of concern • Area of concern Beam Center • Greater femoral trochanter • At 30° toward pubis • Area of concern • Area of concern Field of View • Pelvis to proximal caudal vertebral segments • L6 to proximal caudal vertebra • Includes area of concern plus several vertebra on either side • Includes area of concern plus several vertebra on either side CHAPTER 5 / IMAGING c05.indd 175 175 3/14/2008 11:49:12 AM Shoulder and Forelimb Positioning Skill Box 5.12 / Shoulder and Forelimb Positioning: Scapula–Shoulder Anatomic Area Scapula Shoulder View Lateral—With Tension Lateral—Without Tension Caudocranial Lateral Caudocranial Positioning • Lateral recumbency • Affected forelimb is flexed at the elbow 90° and pulled caudally until the humerus is parallel to the spine and radius/ulna are perpendicular to spine. • Unaffected forelimb is extended caudally. • Lateral recumbency • Affected forelimb extended caudally • Unaffected forelimb extended cranially • Dorsal recumbency • Forelimbs extended cranially. • Sternum is rotated slightly away from the scapula of interest (just opposite midline). • Lateral recumbency • Affected forelimb extended cranially • Unaffected forelimb flexed caudodorsally, parallel to the thorax • Head extended cranially • Dorsal recumbency • Forelimbs extended cranially Measurement • Thickest area of shoulder/cranial thorax • Thickest area of shoulder/cranial thorax • Thickest area of shoulder • Over manubrium • Thickest area of shoulder Beam Center • Mid-scapula • Mid-scapula • Mid-scapula • Shoulder joint • Shoulder joint Field of View • Cranial aspect of the shoulder joint to the caudal scapular crest • Cranial aspect of the shoulder joint to the caudal scapular crest • Shoulder joint to T6 • Mid-scapula to mid-humerus • Mid-humerus to mid-scapula • Used when patient is injured or in pain • Best method for viewing acromial process of scapular spine • Ensure that the manubrium and cranial sternebrae do not overlap shoulder joint. • Be aware of any rotation in the humerus that would result in an oblique view. 5 Notes Skill Box 5.13 / Shoulder and Forelimb Positioning: Humerus Anatomic Area Humerus View Lateral Caudocranial Craniocaudal Positioning • • • • • Dorsal recumbency • Forelimbs are extended cranially. • Affected forelimb is parallel to cassette. • Dorsal recumbency • Affected forelimb is extended caudally alongside the body but just clear of the thorax. Measurement • Thickest area of shoulder • Thickest area of shoulder • Thickest area of shoulder Beam Center • Mid-humerus • Mid-humerus • Mid-humerus Field of View • Shoulder joint to elbow joint • Shoulder joint to elbow joint • Shoulder joint to elbow joint 176 c05.indd 176 Lateral recumbency Affected forelimb is extended cranioventrally. Unaffected forelimb is extended caudodorsally. Head is extended dorsally. SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Skill Box 5.14 / Shoulder and Forelimb Positioning: Elbow Anatomic Area Elbow View Lateral Flexed Lateral Craniocaudal Positioning • Lateral recumbency • Affected limb extended slightly cranioventrally with elbow slightly flexed • Unaffected limb extended caudodorsally • Head is extended dorsally • Lateral recumbency • Affected limb flexed at the elbow joint with carpus pulled toward neck. • Unaffected limb extended caudoventrally • Head is extended dorsally • Sternal recumbency • Affected limb extended cranially • Unaffected limb acts as a support for the animal’s head. • Head is placed resting over unaffected limb. Measurement • Thickest part of elbow joint • Thickest part of elbow joint during flexion • Thickest part of elbow joint Beam Center • Elbow joint • Elbow joint • Elbow joint Field of View • Mid-humerus to mid-radius/ulna • Mid-humerus to mid-radius/ulna • Mid-humerus to mid-radius/ulna Notes 5 • Make sure that, when pulling the carpus, the elbow does not rotate. • This view is best for screening for elbow dysplasia (especially lesions of anconeal process of ulna). • A hyperflexed view also may be needed for diagnostic analysis. CHAPTER 5 / IMAGING c05.indd 177 177 3/14/2008 11:49:13 AM Skill Box 5.15 / Shoulder and Forelimb Positioning: Radius/Ulna and Carpus Anatomic Area 5 Radius/Ulna Carpus View Lateral Craniocaudal Lateral Dorsopalmar Positioning • Lateral recumbency • Affected limb extended cranially and slightly flexed at the elbow • Unaffected limb extended caudally • Head is extended dorsally away from cassette. • Sternal recumbency • Affected limb extended cranially • Unaffected limb extended cranially • Head is placed resting over unaffected limb. • Lateral recumbency • Affected limb extended cranially • Unaffected limb extended ventrally and relaxed • Head is extended dorsally away from cassette. • Sternal recumbency • Affected limb extended cranially • Unaffected limb extended cranially • Head is placed resting over unaffected limb. Measurement • Elbow joint • Thickest area of elbow joint • Distal carpus • Mid-carpus Beam Center • Mid-radius/ulna • Mid-radius/ulna • Mid-carpus • Mid-carpus Field of View • Distal humerus to mid-metacarpals • Distal humerus to mid-metacarpals • Distal radius/ulna to distal metacarpals • Distal radius/ulna to distal metacarpals Notes • Avoid rotation of radius/ulna in cats. • Support under the elbow may assist in maintaining proper carpal positioning. • Stressed views under sedation or general anesthesia may be needed to show presence of ligament laxity. • Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view at a 45° angle also may be required. Skill Box 5.16 / Shoulder and Forelimb Positioning: Metacarpus/Phalanges Anatomic Area Metacarpus/Phalanges View Lateral Dorsopalmar Positioning • • • • • • • • • Measurement • Middle phalanx • Mid-metacarpal Beam Center • Middle phalanges or affected phalanx • Mid-metacarpal Field of View • Distal radius/ulna to distal digits • Distal radius/ulna to distal digits Notes • Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view(s) may be needed in some cases. • Support under the elbow may assist in maintaining proper carpal positioning. • Oblique view at 45º angle also may be required. 178 c05.indd 178 Lateral recumbency Affected limb extended cranially Affected phalange is isolated with gauze or tape and pulled dorsally. Unaffected limb extended caudally and relaxed Head is extended dorsally away from cassette. Sternal recumbency Affected limb extended cranially Unaffected limb is extended cranially. Head is placed resting over unaffected limb. SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Pelvis and Hindlimb Positioning Skill Box 5.17 / Pelvis and Hindlimb Positioning: Pelvis Anatomic Area Pelvis View Lateral Lateral Oblique V/D—Frog Leg V/D—extended Positioning • Lateral recumbency • Hindlimbs are extended down ventrally, slightly apart with the affected limb slightly cranial to unaffected limb, separated with a support to avoid spine rotation. • Lateral recumbency • Affected hindlimb is extended down ventrally and slightly cranially. • Unaffected hindlimb is elevated to a 20º angle dorsally. • Dorsal recumbency • Hindlimbs should be abducted and flexed at a 45º angle to spine, positioned identically. • Dorsal recumbency • Pelvis flat on table • Hindlimbs start in a flexed frog leg position. The area just above the hocks are grasped and limbs are rotated medially so stifles come within 1–2 inches of each other, then extended caudally over the pubis region and ending in a full straight extension of the hindlimbs with patella centered over the femurs. Measurement • Greater trochanter • Greater trochanter • Acetabulum (groin) • Acetabulum (groin) Beam Center • Greater trochanter • Greater trochanter • Pubis/acetabulum • Pubis/acetabulum Field of View • Mid-lumbar spine to mid-femurs • Mid-lumbar spine to mid-femurs • Mid-lumbar spine to mid-caudal vertebrae • Mid-lumbar spine to distal stifle Notes • Best view for L-S bony changes if cauda equina pain suspected • Requires high mA-s to penetrate large dog’s pelvic bones • Used if trauma to the pelvis is suspected • Sandbags and V tray will assist in proper positioning. • Sedation is necessary. • Standard for assessment of hips • Correct positioning will result in parallel femurs; patellae centered between femoral condyles; left and right pelvis should be displayed as a mirror image. • If hip laxity is in question, sometimes the Penn-HIP method is also recommended, which requires special certification of the veterinarian. CHAPTER 5 / IMAGING c05.indd 179 5 179 3/14/2008 11:49:13 AM Skill Box 5.18 / Pelvis and Hindlimb Positioning: Femur, Stifles, and Tibia/Fibula Anatomic Area Femur Stifles Tibia/Fibula View Lateral Craniocaudal Lateral Caudocranial Lateral Caudocranial Positioning • Lateral recumbency • Affected limb joints slightly flexed and relaxed • Unaffected limb extended dorsally or abducted out of the beam • Dorsal recumbency • Affected limb extended caudally with slight abduction • Unaffected limb is flexed and relaxed • Tail (if long) gently laid under unaffected limb • Lateral recumbency • Affected limb slightly flexed and relaxed, with support under the hock if necessary to keep knee from rotating • Unaffected limb extended dorsally out of the beam • Sternal recumbency • Affected limb extended caudally • Unaffected limb is flexed, relaxed, and supported. • Lateral recumbency • Affected limb slightly flexed and relaxed, with support under tarsus to keep tibia from rotating • Unaffected limb extended cranially • Sternal recumbency • Affected limb extended caudally • Unaffected limb is flexed, relaxed, and supported. Measurement • Mid-femur • Mid-femur • Thickest part of stifle • Thickest part of stifle • Mid-tibia/fibula • Mid-tibia/fibula Beam Center • Mid-femur • Mid-femur • Mid-stifle joint • Mid-stifle joint • Mid-tibia/fibula • Mid-tibia/fibula Field of View • Hip joint to proximal tibia/fibula • Hip joint to proximal tibia/fibula • Mid-femur to mid-tibia/fibula • Mid-femur to mid-tibia/fibula • Stifle joint to distal tarsus joint • Stifle joint to distal tarsus joint Notes • Best view for bony neoplasia of femur 5 180 c05.indd 180 • Depending on size of animal, elevation of the pelvic area will alleviate weight off the stifle. SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Skill Box 5.19 / Pelvis and Hindlimb Positioning: Tarsus and Metatarsals Anatomic Area Tarsus Metatarsals View Lateral Plantarodorsal Dorsoplantar Lateral Plantarodorsal Dorsoplantar Positioning • Lateral recumbency • Affected limb slightly flexed and relaxed with support under tarsus • Unaffected limb extended cranially • Sternal recumbency • Affected limb extended caudally with support under the stifle • Unaffected limb is flexed, relaxed, and supported. • Sternal recumbency • Affected limb extended cranially with support under the stifle • Lateral recumbency • Affected limb slightly flexed at stifle and tarsus with support under stifle • Unaffected limb extended cranially • Sternal recumbency • Affected limb extended caudally with support under the stifle • Unaffected limb is flexed, relaxed, and supported. • Sternal recumbency • Affected limb extended cranially with support under the stifle and stifle rotated laterally 5 Measurement • Thickest area of tarsus • Thickest area of tarsus • Thickest area of tarsus • Distal tarsal joint • Distal tarsal joint • Distal tarsal joint Beam Center • Mid-tarsus • Mid-tarsus • Mid-tarsus • Mid-metatarsals • Mid-metatarsals • Mid-metatarsals Field of View • Mid-tibia/fibula to mid-metatarsals • Mid-tibia/fibula to mid-metatarsals • Mid-tibia/fibula to mid-metatarsals • Distal tibia/fibula to distal digits • Distal tibia/fibula to distal digits • Distal tibia/fibula to distal digits Radiographic Contrast Studies Contrast studies are done in cases in which the area of concern cannot be viewed diagnostically from the survey radiographs. The contrast provides the veterinarian with a more thorough observation of the affected area. Many of the procedures listed in the following tables are to be performed by a veterinarian only. However, the tables are provided so the technician can be ready for the procedure and efficiently assist the veterinarian throughout the pro- cedure. Patient preparation is of extreme importance, and the animal should always be clean and dry for these procedures. In some cases, an enema and fasting may be required so that the gastrointestinal tract is clear of food or feces that could superimpose or distort the anatomic images. The technician should be aware of the possible side effects from the contrast medium and be prepared for appropriate emergency procedures. Preparation for these procedures as well as the dosage of the contrast medium should always be reviewed with the veterinarian before the procedure. CHAPTER 5 / IMAGING c05.indd 181 181 3/14/2008 11:49:13 AM Table 5.8 / Types of Contrast Media 5 Contrast Media Positive Insoluble Iodine Classification • Barium sulfate (micropulverized suspension) • Ionic (salt preparation) • Nonionic (low osmolar) • Gases Trade Name • Microtrast, Esophotrast, E-Z Past, Novopaque, Barotrast, Polibar • Conray and Conray 43, Hypaque, Renografin 76 (IV, intraurethral, fistulas, intraperitoneal) • Gastrografin (oral only) • Optiray 240, 320, and 350, Isovue (iopamidol), Omnipaque (iohexol), Visipaque (iodixanol) • Given IV, intraurethrally, into fistulas, intraperitoneally • Carbon dioxide, nitrous oxide, oxygen, and room air Indications • Visualization of esophagus, stomach, small and large bowel, bronchography, and rhinography • Intravascular usage • Intravascular and myelographic studies • Visualization of the bladder, peritoneum, pericardium, joints, and brain Contraindications • Perforations or ruptures suspected • Myelography and arthrography • CHF, dehydration, and renal failure • CHF and renal failure • Areas not able to tolerate a transient reduction or interruption in blood flow Side Effects • Results in granulomas/ lesions if leaks outside GIT • Has excellent mucosalcoating properties, but can mask foreign bodies • Acute renal failure, transient pulmonary edema, diarrhea, dehydration, and vomiting (bitter tasting to cats; use gastric tube to administer) • Less frequently noted • Gases may result in an embolism; possibly fatal if they access the vascular system Monitoring • Vomiting and apnea • Nausea, vomiting, skin erythema, facial swelling, pulmonary edema (respiration), dehydration, hypotension, hypovolemia (pulse, CRT, MM, and temperature) Notes • Radiopaque—shows white on radiograph • Radiopaque—shows white on radiograph • Patient must be well hydrated for any ionic contrast medium. 182 c05.indd 182 Positive Soluble Iodine Negative • Radiolucent—show up black on radiograph • May be combined with other contrast media for doublecontrast images SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Fistula Contrast Studies Abdominal Contrast Studies Skill Box 5.20 / Fistulography Skill Box 5.21 / Abdominal Contrast Studies: Peritoneography Procedure Fistulography Procedure Area of Study • Fistulous tracts and draining wounds Peritoneography (Celiography) Positive Contrast Area of Study Indications • Nonresponsive draining wound • Peritoneal cavity (diaphragm, abdominal wall, and serosal surfaces of abdominal viscera) Contraindications • None Indications • Suspected presence of diaphragmatic hernia Contrast Media • Positive, negative or double Contraindications • None Equipment • Balloon-tip catheter Contrast Media • Positive (iodinated) Patient Preparation • Sedation • Survey radiographs Equipment • ± Catheter/needle Patient Preparation Technique 1. Place catheter into the sinus or fistula. 2. Inject ionic or nonionic iodinated contrast media to fill the cavity. 3. Leave catheter in place and radiograph. • Sedation or general anesthesia • Empty patient’s bladder. • Abdominal survey radiographs Technique 1. Needle or catheter placement into the peritoneal cavity (lateral to midline and caudal to umbilicus) 2. Aspiration test performed (injection into the umbilical fat will invalidate the study) 3. Infusion of nonionic iodinated contrast media and animal rolled carefully 4. Radiograph Radiographic Views • R- and L-LAT, VD, DV Radiographic Views LAT, VD, ± oblique 5 CHAPTER 5 / IMAGING c05.indd 183 183 3/14/2008 11:49:13 AM Gastrointestinal Tract Contrast Studies Skill Box 5.22 / Gastrointestinal Tract Contrast Studies: Esophagography and Gastrography Procedure 5 Esophagography Gastrography Positive Contrast Study Negative Contrast Study (Pneumogastrogram) Double-Contrast Study Area of Study • Esophageal location and morphology • Gastric morphology • Gastric morphology • Gastric morphology Indications • Vomiting of undigested food, gagging, or dysphagia • Gastric masses/foreign body, or vomiting • Gastric masses/foreign body, or vomiting • Gastric masses/foreign body, or vomiting Contraindications • Inability to swallow, bronchoesophageal, rupture/ perforation, or dyspnea • Parasitic infection • Presence of ingesta or fluid • Diabetes mellitus (if glucagon will be used) Contrast Media • Barium sulfate or if perforation is suspected iodinated contrast • Barium sulfate 30–50% • Organic iodide (diatrizoate solution 10%) • Carbon dioxide, nitrous oxide, or oxygen • Barium sulfate 30%–50% and a negative contrast gas Equipment • Large syringe • Wet towels • • • • • Orogastric tube (only if gas is to be used) • Large syringe • 3-way valve • Bite block • • • • • Patient Preparation • Fasting: 12 hours • Survey radiographs • Conscious patient • Fasting: 12–24 hours • Large bowel evacuation or enema • Survey radiographs • Conscious patient • Fasting: 12–24 hours • Survey radiographs • Conscious patient • Fasting: 12–24 hours • Survey radiographs • Conscious patient Technique Technique I Mucosal assessment 1. Place patient in lateral recumbency. 2. Administer positive contrast medium into the buccal pouch. 3.Radiograph as the patient swallows. Technique II Stricture 1. Feed varying sizes of barium-filled gelatin capsules, barium-injected marshmallows, or mix with food. 2. Radiograph 1. Administer positive contrast medium (∼4– 8 mL/kg) orally with a syringe or through an orogastric tube. • Radiograph 1. Insert an orogastric tube into the stomach; verify placement. 2. Administer ∼5–8 mL/kg gas (air or carbon dioxide). 3. Remove orogastric tube and hold muzzle closed while radiographing. 1. Insert an orogastric tube into the stomach; verify placement. 2. Administer positive contrast medium (2 mL/kg). 3. Follow with 10–20 mL/kg gas (air or carbon dioxide) to achieve a tympanic stomach. 4. Roll patient to coat stomach and radiograph. 184 c05.indd 184 Orogastric tube Large syringe Wet towels Bite block Orogastric tube Large syringe Wet towels 3-way valve Bite block SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Skill Box 5.22 / Gastrointestinal Tract Contrast Studies: Esophagography and Gastrography (Continued) Procedure Esophagography Gastrography Positive Contrast Study Negative Contrast Study (Pneumogastrogram) Double-Contrast Study Radiographic Views • R-LAT, R-VD OBL of neck and thorax • R- and L-LAT, DV, VD • R- and L-LAT, DV, VD • R- and L-LAT, DV, VD Notes • Monitor for aspiration of contrast. • Fluoroscopy may aid in evaluation of motility and function. • Iodinated contrast materials are bitter tasting and may result in vomiting. They are also hypertonic (if inhaled, could result in pulmonary edema). • General anesthesia is not recommended because of the risk of aspiration after vomiting. • Monitor for aspiration of contrast. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting. • Monitor for aspiration of contrast. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting. • Monitor for aspiration of contrast. • Fluoroscopy may aid gastric lesion evaluation. • General anesthesia is not recommended because of inhibition of GI motility and risk of aspiration after vomiting. 5 Note: See Skill Box 12.1 Stomach Tube and Gastric Lavage, page 428. Skill Box 5.23 / Gastrointestinal Tract Contrast Studies: Upper and Lower Gastrointestinal Study Procedure Upper Gastrointestinal Study (UGI) Barium Upper Gastrointestinal Study (UGI) Iodinated Contrast Lower Gastrointestinal Study (LGI) Double-Contrast Barium Enema Area of Study • Small intestine morphology and functionality • Small intestine morphology and functionality • Large bowel morphology Indications • Vomiting, diarrhea, neoplasias, or obstructions • Bloody diarrhea • Large bowel obstruction or bloody diarrhea Contraindications • Perforated esophagus or stomach • Lower bowel obstruction • Dehydrated patient • Hypertonic mediums should not be used in hypovolemic patients (e.g., Gastrografin). • Rupture/perforation Contrast Media • Barium sulfate 30% • Ionic or nonionic iodinated contrast • Barium sulfate diluted (10–20%) CHAPTER 5 / IMAGING c05.indd 185 185 3/14/2008 11:49:13 AM Skill Box 5.23 / Gastrointestinal Tract Contrast Studies: Upper and Lower Gastrointestinal Study (Continued) 5 Procedure Upper Gastrointestinal Study (UGI) Barium Upper Gastrointestinal Study (UGI) Iodinated Contrast Lower Gastrointestinal Study (LGI) Double-Contrast Barium Enema Equipment • • • • • • • • • • • • • • • • Examination gloves Warmed barium sulfate Enema syringe Lubricant Foley catheter 3-way stopcock Compression paddle Wet towels Patient Preparation • Fasting: 24 hours • Tepid saline enema 4–12 hours before • Chemical restraint may be necessary; however, do not use parasympatholytic agents. • Conscious patient • Survey radiographs • Fasting: 24 hours • Tepid saline enema 4–12 hours before • Chemical restraint may be necessary; however, do not use parasympatholytic agents. • Conscious patient • Survey radiographs • • • • Fasting: 24 hours Oral laxative and tepid water (or isotonic saline) enema General anesthesia Survey radiographs Technique 1. Administer barium (∼4–8 mL/kg) orally with a syringe or through an orogastric tube. 2. Radiograph 1. Administer iodinated contrast (∼4–8 mL/kg) orally with a syringe or through an orogastric tube. 2. Radiograph 1. Place the animal in right lateral recumbency and insert the balloon catheter in the anus and inflate the balloon to completely occlude the anal canal. 2. Slowly infuse the diluted, body temperature barium sulfate mixture into the large bowel and cecum (∼10–15 mL/kg). 3. Clamp catheter and radiograph (add more contrast medium if bowel distention is not sufficient). 4. After these radiographs have been completed: evacuate the barium, place the animal in left lateral recumbency and infuse gas to redistend the colon. 5. Radiograph Radiographic Views Minute Exposure • 0 minutes: R- and L-LAT, VD • 5–15 minutes: R-LAT, VD • 30 minutes: R-LAT, VD • ± 45 minutes: R-LAT, VD • ± Q60 minutes: R-LAT, VD • Considered complete when stomach is empty and contrast medium is in the large intestines. • LAT, VD every 10–30 minutes until the contrast medium is in the large intestine • Right LAT, VD abdominal after barium infusion and then again after gas infusion Notes • Care must be taken on choice of anesthesia/sedation so as not to impede the motility of the GIT. • Care must be taken on choice of anesthesia/sedation so as not to impede the motility of the GIT. • If study is for diagnosis of obstruction or intussusception, no fecal evacuation is necessary. • Elevation of the cranial two thirds of the body may assist removal of the contrast media. Orogastric tube Wet towels Large syringe Bite block Orogastric tube Wet towels Large syringe Bite block Note: See Skill Box 12.1 Stomach Tube and Gastric Lavage, page 428. 186 c05.indd 186 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:13 AM Head Contrast Studies Skill Box 5.24 / Head Contrast Studies: Dacryocystorhinography, Rhinography, and Sialography Procedure Dacryocystorhinography Rhinography Sialography Area of Study • Nasolacrimal duct • Nasal cavity • Salivary ducts and glands Indications • Conjunctivitis, dacryocystitis, or neoplasia • Suspected obstruction • Mucoceles, swelling, abscesses, or neoplasias Contrast Media • Positive iodinated • Positive (barium sulfate 20%–30% or iodinated media) • Positive iodinated Equipment • Cannula • 23–27-gauge lacrimal needle • Syringe • Syringe • Cannula • Syringe Patient Preparation • General anesthesia • Nasal survey radiographs • General anesthesia • Nasal survey radiographs including lateral and open mouth VD views • General anesthesia • Skull/neck survey radiographs Technique 1. Cannulation of the superior or inferior lacrimal puncta 2. Inject iodinated contrast until several drops are seen in the external nares. 1. Infuse positive contrast into the ventral nasal meatus. 2. With the infused side dependent, elevate the nose approximately 15º. 1. Cannulation of the salivary duct 2. Injection of a small amount of iodinated contrast Radiographic Views • LAT, DV • LAT, VD (open mouth) • LAT, DV 5 CHAPTER 5 / IMAGING c05.indd 187 187 3/14/2008 11:49:14 AM Spinal and Joint Contrast Studies Skill Box 5.25 / Spinal and Joint Contrast Studies: Myelography and Epidurography Procedure Myelography Epidurography Area of Study • Spinal cord • Epidural space Indications • Clinical transverse myelopathies • Disc protrusion/extrusion, suspected lesion, or tumor Contraindications • Disseminated myelopathy, meningopathy, cerebrospinal fluid (CSF) infection Contrast Media • Positive nonionic media only (e.g., iopamidol, iohexol) • Positive nonionic media only (e.g., iopamidol, iohexol) Equipment • 20–22-gauge spinal needle in various sizes: 11/2, 21/2, and 31/2 • Spinal needle Patient Preparation • General anesthesia • Spinal survey radiographs • Aseptic preparation of appropriate spinal location • General anesthesia • Spinal survey radiographs • Aseptic preparation of lumbosacral or coccygeal interarcuate space Technique 1. Aseptic spinal puncture of subarachnoid space at either cisterna magna or an interarcuate space of caudal lumbar spine (L5–L6) 2. Inject nonionic contrast media slowly to fill the subarachnoid space. 3. The needle may be removed or left in place for the radiographs. 1. Place patient in sternal or lateral recumbency. 2. Aseptic placement of spinal needle into the floor of the spinal canal at the lumbosacral or coccygeal interarcuate space 3. Inject nonionic contrast media to fill the space. 4. The needle is removed. Radiographic Views • LAT, VD, DV, OBL, extended/flexed LAT • LAT, flexed LAT, Extended LAT, VD or DV Notes • Tilting of the body may be necessary to assist in the coating of the contrast media. • Elevate head during recovery. • Monitor for apnea and seizures. 5 188 c05.indd 188 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Skill Box 5.26 / Spinal and Joint Contrast Studies: Discography and Arthrography Procedure Discography Arthrography Area of Study • Central portion of intervertebral disc • Joint evaluation (shoulder and stifle) Indications • Hernia or rupture • Articular defects or joint capsule abnormalities Contrast Media • Positive nonionic media only (e.g., iopamidol, iohexol) • Positive iodinated diluted to veterinarian’s recommendation Equipment • • • • Spinal needle Sterile gloves Slides Culture • Sterile gloves • 22-gauge needle • Slides Patient Preparation • • • • • Spinal needle Sterile gloves General anesthesia Spinal survey radiographs Aseptic preparation of appropriate disc space • General anesthesia • Joint survey radiographs • Prepare area around joint of interest. Technique 1. Place patient in lateral recumbency. 2. Aseptical placement of spinal needle through the interarcurate ligament and spinal canal into the disc of interest 3. Inject nonionic contrast media into the space. 4. Radiograph Radiographic Views • Neutral LAT, hyperflexed, LAT, DV or VD Notes 5 1. Aseptic articular puncture 2. Removal of small amount of joint fluid for analysis 3. Diluted nonionic contrast media is injected, dependent on animal size as per veterinarian’s recommended dosage 4. Needle is removed. 5. Joint is manipulated and radiographed. • Caudocranial LAT OBL • Radiographs should be taken as soon as contrast is injected. • Positive contrast study provides more information. • Double-contrast study is not recommended. CHAPTER 5 / IMAGING c05.indd 189 189 3/14/2008 11:49:14 AM Urethra Contrast Studies Skill Box 5.27 / Urethra Contrast Studies: Urethrography, Canine Procedure 5 Urethrography Canine: Male Canine: Female Area of Study • Urethra location and morphology • Urethra location and morphology Indications • Stranguria, hematuria, dysuria, suspected masses or lesions • Stranguria, hematuria, dysuria, suspected masses or lesions Contraindications • Uncontrolled hematuria • Uncontrolled hematuria Contrast Media • Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution) • Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution) Equipment • Urinary catheter (Foley, soft polyethylene male catheter) prefilled with contrast media • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • Lidocaine • Urinary catheter (Foley, Swan-Ganz, soft polyethylene male catheter) prefilled with contrast media • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • Radiolucent paddle or wooden spoon Patient Preparation • • • • • • • • Technique Retrograde Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse undiluted contrast (10–20 mL) to fill urethra. 4. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse enough undiluted contrast to fill the bladder and induce urination. 4. Radiograph during voiding; gentle pressure may need to be applied to the bladder. Retrograde Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse undiluted contrast (5–10 mL) to fill urethra. 4. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 1. Aseptic placement of a urinary catheter to distal urethra 2. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 3. Infuse enough undiluted contrast to fill the bladder and induce urination. 4. Radiograph during voiding; gentle pressure may need to be applied to the bladder. Radiographic Views • LAT (including perineal area) • Repeat infusion for any additional radiographs. • LAT, VD Notes Antegrade • Can be performed after positive contrast cystogram or urethrogram. • Be prepared to catch voided urine. Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs • Lateral of perineal and penile regions with hindlimbs extended cranially Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs Note: See Skill Box 12.10 Urinary Catheterization, page 435. 190 c05.indd 190 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Skill Box 5.28 / Urethra Contrast Studies: Urethrography, Feline Procedure Urethrography Feline: Male and Female Area of Study • Urethra location and morphology Indications • Stranguria, hematuria, dysuria, suspected masses or lesions Contraindications • Uncontrolled hematuria Contrast Media • Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution) Equipment • • • • • • • • Urinary catheter (tomcat catheter for males) prefilled with contrast media Large syringe 3-way stopcock Sterile saline Lubricant Wet towels Bowl Lidocaine Patient Preparation • • • • Fasting: 24 hours Enema 4 hours before Sedation Survey radiographs Technique Retrograde Urethrography 5. Aseptic placement of a urinary catheter to distal urethra 6. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 7. Infuse undiluted contrast (5–10 mL) to fill urethra. 8. Radiograph during administration of the last few mLs of contrast medium. Repeat infusion for additional radiographs. Antegrade Urethrography 5. Aseptic placement of a urinary catheter to distal urethra 6. ± Infuse 2–5 mL of lidocaine to ↓ urethral spasms. 7. Infuse enough undiluted contrast to fill the bladder and induce urination. 8. Radiograph during voiding; gentle pressure may need to be applied to the bladder. Radiographic Views • LAT, ± OBL 5 Note: See Skill Box 12.10 Urinary Catheterization, page 435. CHAPTER 5 / IMAGING c05.indd 191 191 3/14/2008 11:49:14 AM Vaginal Contrast Studies Skill Box 5.29 / Vaginal Contrast Studies: Vaginography Procedure Vaginography Retrograde Vaginourethrography 5 Area of Study • Vagina, cervix, and urethra morphology Indications • Masses, suspected ectopic ureter Contraindications Contrast Media • Iodinated contrast medium (1 part iodine to 2 parts water; 10–15% solution) Equipment • • • • • • • • Urinary catheter (Foley, soft polyethylene male catheter) prefilled with contrast media 2 syringes (20–60 mL) 3-way stopcock Sterile saline Lubricant Wet towels Bowl Suture or Babcock forceps Patient Preparation • • • • Fasting: 24 hours Enema 4 hours before General anesthesia Survey radiographs Technique • • • • Place a urinary catheter into the vulva and cuff inflated just inside the vaginal vault. ± Pursestring suture or a Babcock forceps is used to keep the vulvar lips closed and the Foley catheter in place during the procedure. Infuse with undiluted iodinated contrast media to fill the vagina (e.g., back pressure felt on syringe). Radiograph as the infusion is administered, while the vagina is distended. Radiographic Views • LAT of pelvis and caudal abdomen, ± VD Notes • Overdistention of the vagina forces the contrast medium up the urethra and into the bladder. 192 c05.indd 192 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Urinary Tract Contrast Studies Preparation of the patient is extremely important in producing good-quality contrast radiographs of the urinary tract. An enema should always be done before the procedure, because fecal compression on the ureters or the dorsal bladder wall can ruin a study. The enema should be a warmed isotonic saline enema. Hydration should be assessed and stabilized before beginning any of these procedures. The technician should note the special precautions and monitoring needed when doing an IVU/EU/IVP. Although rare, when complications do occur, they can be fatal, and being prepared for the possible emergency situation can make a difference. Skill Box 5.30 / Urinary Tract Contrast Studies: Cystography Procedure Cystography Procedure Intravenous Urography (IVU), Excretory Urography (EU), Intravenous Pyelography (IVP) Area of Study • Urinary system: kidneys, ureters, and urinary bladder Indications • Pyuria, hematuria, masses, tender abdomen, abnormal renal size, incontinence, trauma, or suspected ectopic ureters Contraindications • • • • Contrast Media • Iodinated contrast for intravascular injection; warmed Equipment • • • • • • • IV catheter; large bore, short (contrast is viscous) Syringe 22-gauge—1-inch needle Iodinated contrast Compression bandage Fluids ready to use Resuscitation kit (epinephrine, AMBU bag, oxygen ready) Patient Preparation • • • • • • • 24-hour fast but have water available Enema (warm, isotonic saline): 4 hours prior Hydration assessed, stabilized, and monitored Urine sample obtained prior to procedure IV catheter Sedation or general anesthesia Abdominal survey radiographs Cystography 5 Intravenous Urography (IVU), Excretory Urography (EU), Intravenous Pyelography (IVP) Technique 1. Rapid (1–3 minutes) intravenous infusion of a warmed iodinated contrast media (3 mL/kg; 90 mL maximum) 2. Radiograph immediately and follow-up radiographs as listed below Radiographic Views Minute Exposure • 0 minutes: VD, LAT • 3–5 minutes: VD, ± LAT, ± VD OBL, ± R-LAT OBL • 10–15 minutes: VD, LAT, ± LAT OBL • 30–120 minutes: VD, LAT, ± LAT OBL Notes • Monitor for hypotension, vomiting, arrhythmia, cardiovascular collapse, anaphylaxis, and contrast medium–induced acute renal failure (CMIARF). • Abdominal compression may be used to visualize the renal collecting system and proximal ureters. • Oblique radiographs may be required to visualize the distal ureters. • Do not use soapy enemas. • Contrast media may cause vasodilation and stinging. • Three stages include nephrogram, pyelogram, and cystogram. Hypovolemia Creatinine >3–3.5 mg/dL Dehydration No compression if abdominal masses or enlarged or cystic kidneys are suspected Note: See Skill Box 8.9 Intravenous Catheter Placement, Peripheral and Jugular, page 349. CHAPTER 5 / IMAGING c05.indd 193 193 3/14/2008 11:49:14 AM Skill Box 5.31 / Urinary Tract Contrast Studies: Cystography (continued) Procedure 5 Cystography Positive Contrast Negative Contrast (Pneumocystography) Double Contrast Area of Study • Urinary bladder wall integrity and position • Urinary bladder • Urinary bladder mucosal detail Indications • Trauma, hematuria, or straining • Trauma, hematuria, or straining • Trauma, hematuria, or straining Contraindications • Enlarged bladder • Enlarged bladder • Enlarged bladder Contrast Media • Iodinated contrast (1 part contrast to 3 parts water) • Gas (carbon dioxide, nitrous oxide, oxygen) • Negative and positive iodinated contrast media Equipment • Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms) • Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms) • Urinary catheter (Foley, tomcat, or soft flexible male catheter) • Large syringe • 3-way stopcock • Sterile saline • Lubricant • Wet towels • Bowl • 5–10 mL 2% lidocaine (to ↓ spasms) Patient Preparation • 24-hour fast • Enema (warm, isotonic saline—4 hours before • Urine sample obtained before procedure • Sedation or general anesthesia • Survey radiographs • 24-hour fast • Enema (warm, isotonic saline—4 hours before • Urine sample obtained before procedure • Sedation or general anesthesia • Survey radiographs • • • • • Technique 1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse positive contrast medium diluted with saline (∼10 mL/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Radiograph 1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse gas (∼10 mL air/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Radiograph 1. Aseptic placement of a urinary catheter to the bladder neck 2. Empty the bladder and note amount remove to estimate amount of contrast medium to use. 3. Infuse 5–10 mL lidocaine to ↓ bladder spasticity. 4. Infuse gas (∼10 mL air/kg) into the urinary catheter and monitor the bladder by palpation until distended. 5. Infuse a small amount (canine: 1–3 mL, feline: 1–2 mL) of iodinated contrast into the urinary catheter. 6. Roll animal to coat bladder wall and radiograph. 194 c05.indd 194 24-hour fast Enema (warm, isotonic saline—4 hours before Urine sample obtained before procedure Sedation or general anesthesia Survey radiographs SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Skill Box 5.31 / Urinary Tract Contrast Studies: Cystography (continued) (Continued) Procedure Cystography Positive Contrast Negative Contrast (Pneumocystography) Double Contrast Radiographic Views • LAT, VD OBL • If further radiographs are necessary, inject additional contrast media. • LAT, VD, ± OBL • If further radiographs are necessary, inject additional contrast media. • LAT, VD OBL Notes • Complications may include trauma due to improper catheterization, iatrogenic infection, or chemical cystitis. • Room air may cause an air embolus; carbon dioxide is recommended. • Complications may include trauma caused by improper catheterization, iatrogenic infection, or air emboli. • Room air may cause an air embolus; carbon dioxide is recommended. • Complications may include trauma caused by improper catheterization, iatrogenic infection, air emboli, or chemical cystitis. 5 Note: See Skill Box 12.10 Urinary Catheterization, page 435. Additional Imaging Techniques In addition to radiographs, the following modalities can be used to further assist in the diagnosis of a patient’s medical problem. Survey radiographs should always be evaluated before any of these modalities. Table 5.9 / Computed Tomography and Echocardiography Procedure Computed Tomography (CT, CAT scan) Echocardiography Definition A cross-sectional image is taken by a rotating image recorder. A set of 3 images is then used by a computer to construct the final image. This technique facilitates easier visualization by avoiding superimposition of surrounding organs. CT is also able to distinguish between gas, fat, fluid, and calcification. Noninvasive study of the heart and its structures (aorta, ventricles, atria, auricular appendages, and all the cardiac valves), using ultrasonography Technique • A thin rotating x-ray beam passes through the patient transaxially, and 3 views of the area of interest are reconstructed by a computer using the transmitted data onto a video screen. • The ultrasound transducer is placed on a clipped and cleaned area with ultrasound gel. M-mode is used to view the cardiac structures and produce the image. The animal may be in lateral or dorsal recumbency or standing if necessary. Indications • Confirmation or further evaluation of radiographic results • Intracranial disease, musculoskeletal, spinal, thoracic, and abdominal disorders • Visualize internal cardiac structures. • Evaluate cardiac function and size, defects (e.g., valvular lesions, shunts, myocardial abnormalities, masses, effusions, stenotic lesions). • Evaluate respiratory distress or pleural effusion. Specialized Equipment • CT unit • Ultrasound machine, transducers, Doppler (permits detection and analysis of blood cells in transit), ultrasound gel Precautions • ↑ Risk of radiation exposure (much larger amounts used in imaging) • None Notes • Two studies are usually required (with and without contrast media). • May be necessary to clip the fur from right 3rd–6th intercostal and left 4th–7th intercostal CHAPTER 5 / IMAGING c05.indd 195 195 3/14/2008 11:49:14 AM Table 5.10 / Fluoroscopy Procedure Fluoroscopy Definition Real-time radiographic viewing of moving anatomic parts, using an x-ray machine and a fluoroscopic screen with an image intensifier Technique • X-rays pass through the patient’s body to the image intensifier tube. Indications • Used in assessing the motility and function of the pharynx, esophagus, stomach, and bowel • Evaluation of respiratory and cardiac function Specialized Equipment • • • • • Precautions • ↑ risk of radiation exposure due to high doses of radiation for this procedure Notes • Bone appears black and gas appears white on image. • Endoscope and ultrasound being used in place of this technique more frequently 5 Fluoroscopic x-ray tube Image intensifier tube Mirror imaging or television viewing system Radiopaque contrast medium Protective apparel Table 5.11 / Magnetic Resonance Imaging and Nuclear Medicine Procedure Magnetic Resonance Imaging (MRI) Nuclear Medicine (Scintigraphy) Definition A cross-sectional view of a patient’s body, using magnetic fields and radio waves The use of radiopharmaceutical drugs to ascertain the functional status of an organ or body part of a patient Technique • A magnet surrounds a patient’s body, and the magnetic field reacts with the hydrogen atoms in the patient’s body, which is then used to reconstruct an image by a computer onto a video screen. • A radionuclide is administered intravenously to the patient. Travel throughout the area is captured on x-ray film, using a gamma scintillation camera. Indications • Confirmation of further evaluation of radiographic results • Soft tissue contrast, brain, and spine • Specific areas requiring more information on functionality of specific organs for diagnostic assessment (e.g., hyperthyroidism, lameness, and liver dysfunction) Specialized Equipment • Magnetic resonance imaging unit • Special room/building for unit • Nonferrous contrast media • • • • • Precautions • Patient and operator must be free of any metallic devices (pacemakers), metallic foreign bodies (bullets, shrapnel, skin staples, etc.), or ferromagnetic implants. • Operator is in a separate area from the patient. • Requires special handling of animal’s excretion and restricted contact time with patient Notes • CT is preferred for bone evaluation. • Specific drugs are used to analyze various areas. 196 c05.indd 196 Radiopharmaceutical drugs Gamma scintillation camera Radiographic film Protective lab coat Specialized training in handling drug and patient’s excretions SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Ultrasonography The indications for the use of ultrasound are extensive and provide an additional level to diagnostics. This noninvasive, nonpainful technique is used as a complement to radiography to allow evaluation, diagnosis, and staging of many diseases. Ultrasound is the best modality for the evaluation of fluid- filled and soft tissue organs, most importantly the heart. Doppler ultrasonography is an additional technique used to identify blood flow and velocity and calculate pressure of the heart and uterus. Ultrasound also excels at diagnosing discrete changes not apparent on any other test. Due to the minute complexities of ultrasound findings, it is often necessary to seek the opinion of a board-certified veterinary radiologist, when feasible and/or practical. Table 5.12 / Ultrasonography a Procedure Ultrasonography Definition The production of a computer image based on the emission and return of sound waves from the ultrasound’s transducer into an animal’s body Technique • Ultrasound transducing gel is placed on the clipped and cleaned area of interest. A transducer probe is placed on the gel. B-mode is used to view the abdominal structures. Sound waves are emitted through the transducer into the body, the sound waves strike the internal structures, and then send echoes back to the transducer. The received echoes are then reproduced as a gray scale image on the screen. Indications • Confirmation or further evaluation of anomalies found on radiographs • Evaluation of specific endocrine disorders (e.g., adrenal and thyroid glands) or injury/disease of: joints, tendons, cardiac, thoracic, renal, hepatic, GIT, abdominal, urogenital, ocular, vascular, pregnancy, soft tissue • Assessment of cardiac function with a Doppler ultrasonography Specialized Equipment • Ultrasound machine • Appropriate transducers (e.g., 5-, 7.5-MHz transducers) • Ultrasound gel Precautions • Biopsy complications (e.g., hemorrhage, organ laceration) due to lack of direct visualization • Artifacts on examination can lead to misleading information and an incorrect diagnosis or treatment (experience of operator critical). Notes • • • • • • 5 Sedation or general anesthesia may be necessary for ultrasound-guided needle aspirations and commonly used for core biopsies. Sedation if necessary for anxious or fractious patients. Sedation and general anesthesia are contraindicated when performing an echocardiogram. Owners should be made aware that a large area of fur may be clipped. Wipe probe clean of gel as soon as possible. Wash transducer probe with cold water (do not immerse) and dry with a soft towel. Pregnancy confirmation can be done 20 (feline) or 25 (canine) days post breeding, earlier than radiographic dates. CHAPTER 5 / IMAGING c05.indd 197 197 3/14/2008 11:49:14 AM Skill Box 5.32 / Ultrasonography: Basic Scanning Techniquea 5 5. Choose the highest frequency transducer possible for the patient and area under examination. This provides the best resolution but also limits depth of penetration of the sound beam. 6. Set the power setting as low as possible but so that the most distal structure in the field can be seen. 7. Use the time gain compensation control to obtain an image of uniform brightness. 8. Do not press the transducer too hard against the patient as this may cause discomfort. Simply use sufficient pressure to maintain good contact between the skin and the transducer. 9. Scan slowly and thoroughly to ensure complete examination of each structure, scanning organs in at least 2 planes to allow a threedimensional impression to be built up from the cross-sectional images. 1. Prepare the patient: a. GIT scans: withhold food for 12 hours. b. Urinary tract scans: a full bladder is helpful. c. Clip and clean area of interest. d. ± sedation/anesthesia 2. Position the animal in a consistent orientation on the scanning table (this will make learning and consistent orientation of images easier). 3. If right-handed, it is usually easiest to hold the transducer in the right hand and use the left hand to make control panel adjustments. 4. Dim the room lighting to reduce reflections from the screen and enhance visualization of the image. a Reprinted from BSAVA Manual of Advanced Veterinary Nursing (1999), page 129; edited by Alasdair Hotston Moore with publisher’s permission. Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga Organ Position of Animal Area to Clip Applications Liver and Gall Bladder • Dorsal or lateral recumbency or standing (may need to reposition to relocate bowel gas if it interferes) • Ventral abdomen from xiphisternum to umbiculus, for several centimeters, to either side of midline Liver: (deep-chested dogs) • Left lateral recumbency • Ventral third of last 4 ribs on right. Position transducer in intercostals spaces • • • • • Spleen • Dorsal or right lateral recumbency • As for liver, but extend farther caudally. Locate head of spleen on left, then follow body and tail. • Focal lesions (e.g., tumors) • Diffuse lesions (e.g., venous congestion, tumors) Kidney • Lateral recumbency with kidney to be examined uppermost (or can use sternal recumbency or standing) • Slightly beneath sublumbar muscles • L: behind last rib • R: over last 2 intercostal spaces • Dorsal recumbency • Ventral abdomen (but flank approach as above is best) • • • • • 198 c05.indd 198 Focal lesions (e.g., tumors) Diffuse lesions (e.g., cirrhosis) Biliary obstruction Portocaval shunts Venous congestion Focal lesions (e.g., cysts) Diffuse lesions (e.g., tumors) Hydronephrosis Pyelonephritis Renal calculi SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:14 AM Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga (Continued) Organ Position of Animal Area to Clip Applications Ovary • Lateral recumbency as for kidney • As for kidney • Adrenal located cranial pole of kidney • Polycystic ovaries • Tumors Adrenal • Lateral recumbency as for kidney • As for kidney • Adrenal located cranial pole of kidney • Hyperplasia (e.g., Cushing’s) • Neoplasia Bladder • Dorsal or lateral recumbency or standing • Ventral midline from umbilicus to pubic brim, or to 1 side of prepuce in male dogs • Cystic calculi • Tumors • Cystitis Prostate • Dorsal or lateral recumbency • To 1 side of prepuce just in front of pubic brim. Locate bladder, then move caudally. • Focal lesions (e.g., cysts) • Diffuse lesions (e.g., tumors) • Paraprostatic cysts Uterus • Dorsal or lateral recumbency • Ventral midline from umbilicus to pubis • • • • Testicle and Scrotum • Dorsal or lateral recumbency • Scrotal testicles rarely require any clipping • Scrotal hernia • Tumors • Abscesses Cryptorchid Testicle • Dorsal or lateral recumbency • Pubis to umbilicus on appropriate side of midline. Start in front of pubis and work toward bladder and then kidney. • Location of intra-abdominal testicle Pancreas • Dorsal recumbency • Entire ventral abdomen from xiphistermun to umbilicus • Pancreatitis • Tumors Gastrointestinal Tract • Dorsal recumbency • Entire ventral abdomen • Bowel wall thickening • Intussusception • Intestinal tumors Abdomen • Dorsal recumbency • Entire ventral abdomen • Free fluid • Unidentified masses (e.g., mesenteric tumors) Heart • Left and right lateral recumbency • Best to use a table with a hole cut so can scan from beneath; this keeps heart close to chest wall and keeps lung out of the way. • Ventral third of ribs 4–6. • Transducer placed in intercostal spaces • • • • 5 Pregnancy diagnosis Fetal distress/death Pyometra Stump granuloma Pericardial effusion Valvular disease Myocardial disease Congenital defects CHAPTER 5 / IMAGING c05.indd 199 199 3/14/2008 11:49:14 AM Skill Box 5.33 / Ultrasonography: Sites for Ultrasound Scanninga (Continued) 5 Organ Position of Animal Area to Clip Applications Thorax • Left and right lateral recumbency • Over area of interest • Free fluid • Masses (e.g., thymic lymphoma, chest wall masses) • Diaphragmatic rupture Eye • Most useful if direct visualization obscured • Use local anesthetic drops on cornea • Place transducer directly on cornea (can scan through closed eyelids but image not as good). • Retinal detachment • Intraocular masses Orbit • As for the eye • As for the eye • Retrobulbar foreign bodies, abscesses, tumors a Reprinted from BSAVA Manual of Advanced Veterinary Nursing (1999), pages 129–130; edited by Alasdair Hotston Moore with publisher’s permission. 200 c05.indd 200 SECTION THREE: DIAGNOSTIC SKILLS 3/14/2008 11:49:15 AM Uterine horn Ovary Ureter Colon Esophagus Right kidney Lungs Trachea Lungs Spleen Left kidney Stomach Ureter Anus Urinary bladder Liver Heart Greater omentum (covering small intestines) Liver Thymus Colon Small intestines Urinary bladder Heart (cardiac notch) Figure 1.6 Internal organs: left lateral view. Figure 1.7 Internal organs: right lateral view. Esophagus Trachea Left subclavian artery Lung Heart Superior vena cava Aortic arch Pulmonary arteries Left atrium Pulmonary veins Diaphragm Liver Left auricle Right atrium Liver Gall bladder Common bile duct Lesser omentum Stomach Greater omentum (cut) Liver Duodenum Pancreas Transverse colon Ascending colon Cecum Spleen Jejunum Ileum Pulmonary veins Left ventricle Inferior vena cava Coronary artery Right ventricle Apex Rectum Descending colon Mesentery Figure 1.9 Circulatory: dorsal view of heart. Anal gland Figure 1.8 Internal organs: ventral view. CP-1 Left subclavian artery Aorta Superior vena cava Right auricle Right atrium Tricuspid valve Right ventricle Figure 1.12 Circulatory: lateral view. Apex Semilunar valves of aorta Left atrium Vagosympathetic trunk Brachial plexus Lumbo-sacral plexus Vagus Sciatic Bicuspid valve Left ventricle Chordae tendineae Femoral Radial Median Ulnar Ventral papillary muscle Figure 1.10 Circulatory: internal view of heart. Figure 1.14 Nervous system: lateral view. CP-2 Tibial Figure 4.1 Top: Canine bone marrow aspirate showing erythroid precursors (e.g., round nuclei, coarse chromatin, blue to red cytoplasm). Bottom: The stages of erythrocyte maturation: 1, rubriblast; 2, prorubricyte; 3, rubricyte; 4, metarubricyte; 5, polychromathilic erythrocyte; 6, mature erythrocyte. (From Veterinary Hematology and Clinical Chemistry, page 151, Figure 13.4.) Figure 4.3 Maturation stages of megakaryocytes. Large arrow, megakaryoblasts; arrowhead, promegakaryocyte; small arrow, mature megakaryocyte. (From Veterinary Hematology and Clinical Chemistry, page 153, Figure 13.8.) Figure 4.2 Top: Canine bone marrow aspirate showing granulocytic precursors (e.g., irregularly shaped nuclei, fine chromatin pattern, purple cytoplasm). Bottom: The stages of granulocyte maturation: 1, myeloblast; 2, promyelocyte; 3, myelocyte; 4, metamyelocyte; 5, band neutrophil; 6, segmented neutrophil. (From Veterinary Hematology and Clinical Chemistry, page 151, Figure 13.5.) CP-3 Figure 4.5 Histiocytoma: poikilocytosis, variable amount of blue cytoplasm, ↑ nuclear/cytoplasm ratio, round, oval, or irregularly shaped nuclei with lacy or finely stippled chromatin pattern. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.7 Mast cell tumor: anisocytosis, round to oval nuclei, stain palely, fine to coarse, reddish-purple granules within the cytoplasm. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.6 Lymphoma: dense nuclear margins, basophilic cytoplasm, granular chromatin, ↑ nuclear/cytoplasm ratio, and ≥ nucleolus. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.8 Clostridium: large rods, “safety pin” appearance (non-staining spore within the sporangium). (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) CP-4 Figure 4.9 Giardia: pear-shaped, concave ventral surface, two outlined nuclei resembling eyes along with a nose and mouth, forward or “falling leaf” motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.11 Spirochetes: stiff corkscrew helical rods with tight spirals, corkscrewing motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.10 Campylobacter: tiny, curved rods, two attached together as a “seagull” or “W” shape, “swarm of bees,” rapid and darting motility. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.12 Yeast: rarely internal structures; smaller than Giardia. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) CP-5 Figure 4.13 Top: canine IMHA blood smear (e.g., regenerative anemia, polychromatophilic erythrocytes, nucleated erythrocytes [arrowheads]) and Howell-Jolly body (arrow). Bottom left: lead poisoning, basophilic stippling (small arrow). Bottom right: arrow, Howell-Jolly body. (From Veterinary Hematology and Clinical Chemistry, page 76, Figure 5.15.) Figure 4.14 Distemper (arrows): round, oval, or irregular faint blue inclusions. (From Veterinary Hematology and Clinical Chemistry, page 79, Figure 5.23.) CP-6 Figure 4.15 Feline blood smear showing macrocytic gray-blue polychromatophilic and normal RBCs, neutrophil, platelets, Howell-Jolly body (large arrow), and Hemobartonella felis (small arrows). (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1066, Figure 164.3.) Figure 4.16 Canine blood smear showing polychromatophilic erythrocytes (arrowheads), nucleated RBCs (rubricytes and metarubriytes—thin arrows), and spherocytes (thick arrows). (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1058, Figure 163.2.) Figure 4.17 Feline blood smear showing reticulocytes (aggregate and punctate), platelets, and polychromatic RBCs with Heinz bodies. The Heinz bodies are also seen floating freely in the background. (From Schalm’s Veterinary Hematology, page 115, Figure 19.4.) Figure 4.19 Canine blood smear: leptocytes (arrows), folded cells (arrowheads). (From Veterinary Hematology and Clinical Chemistry, page 75, Figure 5.12.) Figure 4.18 Feline blood smear showing iron-deficiency anemia. Blister cells (small arrows) and keratocytes (large arrows) are present. Insert: Canine blood smear showing iron-deficiency. Blister cell (small arrow) and hypochromic erythrocyte (arrowhead). (From Veterinary Hematology and Clinical Chemistry, page 73, Figure 5.5.) Figure 4.20 Canine blood smear showing anemia from a patient with a ruptured hemangiosarcoma of the spleen. Left: Acanthocytes (arrows) and polychromatophilic cells. Right: Acanthocytes (arrows) and schistocytes (arrowheads). (From Veterinary Hematology and Clinical Chemistry, page 73, Figure 5.6.) CP-7 Figure 4.21 Paired, teardrop-shaped structures of a dog infected with Babesia canis. (From Schalm’s Veterinary Hematology, page 158, Figure 27.7.) Figure 4.22 Small, irregular rings found in the RBCs of a cat infected with Cytauxoon felis. (From Schalm’s Veterinary Hematology, page 160, Figure 27.10.) CP-8 Figure 4.23 Example of the multiple appearances of the segmented neutrophil nucleus. Band neutrophils begin with a horseshoe-shaped nucleus, and as it ages, the nucleus continues to segment. (From Veterinary Hematology and Clinical Chemistry, page 126, Figure 10.2.) Figure 4.24 Example of the multiple appearances of lymphocytes. Nucleus varies from oval to round. Cell shape varies with indentation (small arrow) by surrounding RBCs. Lymphocyte size is typically smaller than a neutrophil (large arrow). Amount of cytoplasm varies between cells. (From Veterinary Hematology and Clinical Chemistry, page 126, Figure 10.3.) Figure 4.27 Example of the multiple appearances of eosinophils. Eosinophils are typically larger than neutrophils (arrowheads). C (canine): variable granular size and dissolving granules during staining to appear as cytoplasmic vacuoles. F (feline): barrel of rod-shaped granules that vary in density. (From Veterinary Hematology and Clinical Chemistry, page 128, Figure 10.7.) Figure 4.25 Example of the multiple appearances of monocytes. Nucleus may be round, bean, amoeboid, or horseshoe shape or segmented. Cytoplasm may contain vacuoles. Monocytes are typically larger and have a darker blue-gray cytoplasm compared to a neutrophil (large arrow). (From Veterinary Hematology and Clinical Chemistry, page 127, Figure 10.5.) Figure 4.26 Canine blood smear with a vacuolated monocyte and RBCs exhibiting distinct central pallor. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1058, Figure 163.1.) Figure 4.28 Example of the multiple appearances of basophils. Basophils are larger than neutrophils (inset square). C (canine): sparsely granulated. F (feline): large, poorly staining gray granules packed in the cytoplasm. (LA, large animal.) (From Veterinary Hematology and Clinical Chemistry, page 129, Figure 10.8.) CP-9 Figure 4.29 Canine blood smear showing the segmented nucleus of a neutrophil (arrow), eosinophil (arrowhead) with variable sized particles and vacuoles, and a basophil with dark purple granules and a segmented nucleus. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1061, Figure 163.9.) Figure 4.30 Feline blood smear showing moderate anisocytosis, Howell-Jolly body (small arrow), segmented neutrophils, lymphocyte, eosinophil, and platelets. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1065, Figure 164.1.) CP-10 Figure 4.31 Canine blood smear showing a megathrombocyte (arrow), spherocytes, polychromatophilic erythrocytes, neutrophil, and a reactive lymphocyte. (Photograph courtesy of Oklahoma State University Clinical Pathology Teaching Files. From Schalm’s Veterinary Hematology, page 1060, Figure 163.7.) Figure 4.32 Canine blood smear showing toxic change in a segmented and band neutrophil. Toxic change showing cytoplasmic basophilia and Dühle bodies. (From Schalm’s Veterinary Hematology, page 371, Figure 55.5.) Figure 4.33 Neutrophils showing toxic change with prominent cytoplasmic basophilia. Döhle Body (small arrow). Upper left inset: normal neutrophil. Lower right inset: toxic neutrophil with fine cytoplasmic vacuolation. (From Veterinary Hematology and Clinical Chemistry, page 137, Figure 12.3.) Figure 4.36 Ancylostoma caninum. (From Internal Parasites of Dogs and Cats, page 7.) Figure 4.34 Malassezia: small oval cells surrounded by a halo seen intracellularly in monocytic cells. (Courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.37 Ancylostoma tubaeforme. (From Internal Parasites of Dogs and Cats, page 7.) CP-11 Figure 4.38 Crytosporidium. (Courtesy of Gary A. Averbeck.) Figure 4.40 Dirofilaria immitis. (From Internal Parasites of Dogs and Cats, page 3.) Figure 4.39 Dipylidium caninum. (From Internal Parasites of Dogs and Cats, page 5.) CP-12 Figure 4.41 Echinococcus granulosus. (From Internal Parasites of Dogs and Cats, page 5.) Figure 4.42 Giardia spp. (From Internal Parasites of Dogs and Cats, page 11.) Figure 4.43 Isospora spp. (From Internal Parasites of Dogs and Cats, page 11.) Figure 4.44 Taenia spp. (From Internal Parasites of Dogs and Cats, page 6. Figure 4.45 Toxocara canis (top)/Toxascaris leonina (bottom). (From Internal Parasites of Dogs and Cats, page 9). Figure 4.50 Cheyletiella. (From External Parasites of Dogs and Cats, page 14.) Figure 4.46 Toxocara cati. (From Internal Parasites of Dogs and Cats, page 10.) Figure 4.51 Ctenocephalides canis. (From External Parasites of Dogs and Cats, page 3.) Figure 4.48 Trichuris vulpis. (From Internal Parasites of Dogs and Cats, page 10.) Figure 4.52 Demodex canis. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) Figure 4.47 Toxoplasma gondii. (From Internal Parasites of Dogs and Cats, page 12.) Figure 4.49 Uncinaria stenocephala. (From Internal Parasites of Dogs and Cats, page 8.) Figure 4.53 Dermacentor variabilis. (From External Parasites of Dogs and Cats, page 25.) CP-13 Figure 4.56 Rhipicephalus sanguineus. (From External Parasites of Dogs and Cats, page 25.) Figure 4.54 Linognathus setosus. (From External Parasites of Dogs and Cats, page 10.) Figure 4.57 Sarcoptes scabiei canis. (From External Parasites of Dogs and Cats, page 17.) Figure 4.55 Otodectes cynotis. (Photograph courtesy of J. Michael Harter, DVM, originally published on Veterinary Information Network.) CP-14 Figure 4.58 Trichodectes canis. (From External Parasites of Dogs and Cats, page 10.) Figure 4.59 Bacteria. Top left: rods, unstained; top right: amorphous crystals, unstained: bottom left: cocci, unstained; bottom right: cocci, gram stain. (Photograph courtesy of Joyce S. Knoll, VMD, PhD, DACVP.) CP-15 Figure 4.60 Bacteria. [Photograph courtesy of Cheryl Stockman, MT (ASCP).] Figure 4.62 WBCs. [Photograph courtesy of Cheryl Stockman, MT (ASCP).] Figure 4.61 Bacteria. (From Graff’s Handbook of Routine Urinalysis, page 116, Figure 3-51.) Figure 4.63 WBCs. (From Graff’s Handbook of Routine Urinalysis, page 77, Figure 3-4.) CP-16 Figure 4.64 Epithelial cells, WBCs, RBCs, and bacteria. (From Graff’s Handbook of Routine Urinalysis, page 134, Figure 4-2.) Figure 4.66 Fatty cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).] Figure 4.65 Epithelial cast. (From Graff’s Handbook of Routine Urinalysis, page 113, Figure 3-47.) Figure 4.67 Granular cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).] CP-17 Figure 4.69 RBC cast and RBCs. (From Graff’s Handbook of Routine Urinalysis, page 110, Figure 3-43.) Figure 4.68 Hyaline cast. [Photograph courtesy of Cheryl Stockman, MT (ASCP).] Figure 4.70 WBC cast. (From Graff’s Handbook of Routine Urinalysis, page 194, Figure 4-92.) CP-18 Figure 4.71 Waxy cast. (From Graff’s Handbook of Routine Urinalysis, page 208, Figure 4-112.) Figure 4.72 Amorphous phosphate crystals. (From Graff’s Handbook of Routine Urinalysis, page 103, Figure 3-36.) Figure 4.73 Amorphous urate crystals and an air bubble. (From Graff’s Handbook of Routine Urinalysis, page 128, Figure 3-67.) Figure 4.74 Amorphous biurate crystals and mucous threads. (From Graff’s Handbook of Routine Urinalysis, page 180, Figure 4-71.) CP-19 Figure 4.75 Bilirubin crystals. (From Graff’s Handbook of Routine Urinalysis, page 170, Figure 4-55.) Figure 4.78 Cystine crystals and air bubbles. (From Graff’s Handbook of Routine Urinalysis, page 93, Figure 3-23.) Figure 4.76 Calcium carbonate crystals. (From Graff’s Handbook of Routine Urinalysis, page 104, Figure 3-37.) Figure 4.79 Leucine crystals. (From Graff’s Handbook of Routine Urinalysis, page 94, Figure 3-24.) Figure 4.77 Calcium oxalate dihydrate crystals. (From Graff’s Handbook of Routine Urinalysis, page 152, Figure 4-29.) Figure 4.80 Sulfonamide crystals. (From Graff’s Handbook of Routine Urinalysis, page 163, Figure 4-45.) CP-20 Figure 4.81 Triple phosphate crystals. (From Graff’s Handbook of Routine Urinalysis, page 170, Figure 4-56.) Figure 4.84 Renal epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 139, Figure 4-9.) Figure 4.82 Tyrosine crystals. (From Graff’s Handbook of Routine Urinalysis, page 165, Figure 4-48.) Figure 4.85 Squamous epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 141, Figure 4-12.) Figure 4.83 Uric acid crystals. (From Graff’s Handbook of Routine Urinalysis, page 144, Figure 4-16.) Figure 4.86 Transitional epithelial cells. (From Graff’s Handbook of Routine Urinalysis, page 81, Figure 3-8.) CP-21 Figure 4.87 Epithelial cells and lipid droplets. (From Graff’s Handbook of Routine Urinalysis, page 220, Figure 4-130.) Figure 4.89 Starch granules. (From Graff’s Handbook of Routine Urinalysis, page 123, Figure 3-59.) Figure 4.90 Yeast. (From Graff’s Handbook of Routine Urinalysis, page 217, Figure 4-126.) Figure 4.88 Capillaria plica. (From Internal Parasites of Dogs and Cats, page 14.) CP-22 CP-23 Figure 9.1 Colorado State University Canine Acute Pain Scale. See Skill Box 9.1, Instructions for Using the CSU Acute Pain Scale. (Courtesy of Peter Hellyer, DVM, MS, DACVA, and Narda Robinson, DO, DVM, Colorado State University.) CP-24 Figure 9.2 Colorado State University Feline Acute Pain Scale. See Skill Box 9.1, Instructions for Using the CSU Acute Pain Scale. (Courtesy of Peter Hellyer, DVM, MS, DACVA, and Narda Robinson, DO, DVM, Colorado State University.) Chapter 6 General Medicine Cardiopulmonary 204 Asthma and Brachycephalic Airway Syndrome 204 Bronchitis and Cardiomyopathy, Hypertrophic 205 Cardiomyopathy, Dilated 208 Cardiomyopathy, Restrictive and Congenital Heart Disease 210 Endocardiosis and Heartworm Disease 211 Congestive Heart Failure 214 Hypertension and Myocarditis 215 Pneumonia and Pleural Effusion 217 Rhinitis/Sinusitis and Tracheal Collapse 219 Dermatology 220 Acne 220 Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis 222 Food Hypersensitivity and Otitis Externa 224 Pyoderma 225 Endocrinology and Reproduction 227 Abortion and Diabetes Insipidus 227 Diabetes Mellitus 228 6 Dystocia and Eclampsia 230 Hyperadrenocorticism and Hyperparathyroidism 231 Hyperthyroidism and Hypoadrenocorticism 233 Hypoparathyroidism, Hypothyroidism, and Mastitis 235 Pregnancy and Pyometra 237 Gastroenterology 238 Anal Sac Disease, Cholangitis, and Cholangiohepatitis 238 Constipation and Megacolon 240 Diarrhea 241 Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus 243 Hepatic Disease/Failure 245 Hepatic Lipidosis and Inflammatory Bowel Disease 246 Megaesophagus 248 Pancreatitis and Peritonitis 249 Protein-Losing Enteropathy and Vomiting 251 Hematology 253 Anemia and Disseminated Intravascular Coagulation 253 Thrombocytopenia and von Willebrand’s Disease 254 201 Infectious Diseases 256 Brucellosis and Erhlichiosis 256 Rocky Mountain Spotted Fever and Salmon Poisoning Tetanus and Toxoplasmosis 259 Musculoskeletal 261 Arthritis 261 Cruciate Disease and Hip Dysplasia 263 Osteochondrosis and Osteomyelitis 264 Patellar Luxation and Panosteitis 266 Neurology 267 Encephalitis and Epilepsy 267 6 Intervertebral Disc Disease and Meningitis 269 Myasthenia Gravis and Myelopathy 271 Vestibular Disease and Wobbler Syndrome 272 Oncology 273 Neoplasia 273 Key Words and Termsa Adulticidal Alopecia Amyloidosis Ankylosis Aphakic Aqueous flare Arthrodesis Ascites Ataxia Atrial fibrillation Azotemia Bacteremia Biomicroscopy Blepharospasm Borborygmus Bronchiectasis Cachexia Cardiac tamponade Chemosis Comedones Coprophagia 202 258 Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor 275 Various Neoplasias 277 Ophthalmology 284 Anterior Uveitis and Cataracts 284 Conjunctivitis and Entropion 285 Cilia Disorders and Glaucoma 287 Keratitis and Keratoconjunctivitis Sicca 288 Lens Luxation and Prolapsed Gland of the Third Eyelid 290 Urology 292 Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis 292 Renal Failure 294 Urinary Tract Obstruction and Urinary Tract Infection 296 Abbreviations Crepitus Cyanosis Dermatophytosis Descemetocele Diskospondylitis Dyschezia Dysphagia Dysphonia Eczema Edema Edematous Encephalopathy Endophthalmitis Epididymitis Epiphoria Epistaxis Erythropoietin Fetid Folliculitis Furunculosis Glomerulonephropathy SECTION THREE: DIAGNOSTIC SKILLS μg, microgram μmol, micromole ACE, angiotensin-converting enzyme AChR, acetylcholine receptor ACT, activated clotting time ACTH, adrenocorticotropic hormone ADH, antidiuretic hormone AGID, agar-gel immunodiffusion Alk phos, alkaline phosphatase ALP, alkaline phosphatase ALT, alanine aminotransferase ANA, antinuclear antibody APC, atrial premature contraction/ complex ARF, acute renal failure AST, aspartate aminotransferase BP, blood pressure BUN, blood urea nitrogen CBC, complete blood count CK, creatine kinase CNS, central nervous system Additional Resources, page cPLI, canine pancreatic lipase immunoreactivity CRF, chronic renal failure CRT, capillary refill time CT, computed tomography DIC, disseminated intravascular coagulation DJD, degenerative joint disease dL, deciliter DNA, deoxyribonucleic acid DOCP, desoxycorticosterone pivalate ECG, electrocardiogram EEG, electroencephalogram ELISA, enzyme-linked immunosorbent assay FBD, feline bronchopulmonary disease FDP, fibrin degradation product FeLV, feline leukemia virus FLUTD, feline lower urinary tract disease Abdominocentesis, 429 Anatomy, 3 Bandaging, 405 Bathing, 53 Blood chemistries, 74 Blood gas analysis, 335 Blood pressure, 332 Blood transfusion, 367 Cardiac examination, 30 Central venous pressure, 334 Chemotherapy, 352 Chest tube placement, 431 Coagulation profiles, 115 Complete blood count, 104 Coupage, 432 Cytology, 88 Disinfectants, 627 Drug administration, 348 Electrocardiogram, 338 Endoscopy, 551 Enema, 430 Key Words and Termsa Goniometry Halitosis Hematochezia Hematuria Hemoptysis Hepatomegaly Hyperesthesia Hypertrophic Hypotonia Icterus Ileus Impetigo Inertia Intussusception Iridodenesis Isothenuric Jaundice Leukocytosis Leukopenia Lymphadenomegaly Lymphadenopathy Macrocytosis Mastocythemia Megathrombocytosis Melena Menace response Metastasis Microhepatica Morbidity Mortality Mucopurulent Myalgia Myxedema Neovascularization Nocturia Normochromic Normocytic Nystagmus Oocyst Osteopenia a Abbreviations Palliative Pallor Pancytopenia Panophthalmitis Paresis Periuria Petechiae Phthisis bulbi Pica Pleomorphism Pleuritis Poikilocytosis Pollakiuria Prophylactic Pruritus Psychogenic Puerperal Pulse deficits Pyrexia Retinopathy Sclerosed Seborrheic Steatorrhea Stertor Strabismus Stranguria Stratum corneum Stridor Syncope Synechia Tenesmus Tetany Thrombocytopenia Thromboembolism Trigone Trismus Turgor Uveitis FNA, fine needle aspirate (aspiration) fPLI, feline pancreatic lipase immunoreactivity FUS, feline urologic syndrome GGT, gamma glutamyl transpeptidase GI, gastrointestinal HAC, hyperadrenocorticism IFA, immunofluorescent assay IgG, immunoglobulin gamma E IgM, immunoglobulin gamma IM, intramsucular IMHA, immune-mediated hemolytic anemia IMT, immune-mediated thrombocytopenia ITP, idiopathic thrombocytopenic purpura IV, intravenous IVDD, intervertebral disc disease K, potassium KBr, potassium bromide KCS, keratoconjunctivitis sicca LA, left atrium LDH, lactate dehydrogenase LRS, lactated Ringer’s solution LV, left ventricular MCHC, mean corpuscular hemoglobin concentration MCV, mean corpuscular volume mg, millgram MRI, magnetic resonance imaging NPH, neutral protamine hagedon NPO, nothing by mouth NS, nonsuppurative NSAIDs, nonsteroidal antiinflammatory drugs Additional Resources, page OCD, osteochondrosis dessicans OVH, ovariohysterectomy PABA, para-aminobenzoic acid PCR, polymerase chain reaction PCV, packed cell volume PD, polydipsia PDT, photodynamic therapy PE, physical examination pg, picogram pH, potential of hydrogen PPA, phenylpropanolamine PT, prothrombin time PTH, parathyroid hormone PTT, partial thromboplastin time PU, polyuria PZI, protamine zinc insulin RAST, radioallergosorbent test RBC, red blood cell ROM, range of motion S, suppurative SAP, alkaline phosphatase T3, triiodothyronine T4, tetraiodothyronine TLI, trypsin-like immunoreactivity TP, total protein TPLO, tibial plateau leveling osteotomy TSH, thyroid-stimulating hormone UA, urinalysis UTI, urinary tract infection v, variable VD, ventrodorsal VPC, ventricular premature contraction/complex vWF, von Willebrand disease WBC, white blood cell Fecal analysis, 134 Fluid therapy, 359 Heat administration, 346 Immunology and serology, 120 Injections, 348 Insulin administration, 357 Laboratory, 71 Lymph node examination, 34 Magnetic resonance imaging, 196 Medical procedures, 427 Metered dose inhalers, 431 Microbiology, 122 Nebulization, 432 Nutrition, 57 Obesity management, 67 Orthopedic examination, 36 Otoscopic examination, 33 Oxygen therapy, 375 Pain management, 379 Parenteral nutrition, 413 Pharmacology, 567 Physical examination, 18 Physical therapy, 558 Pulmonary examination, 32 Pulse oximetry, 463 Radiographic contrast studies, 181 Radiology, 159 Recumbent patient care, 347 Surgery, 521 Thoracocentesis, 431 Ultrasonography, 197 Urinalysis, 147 Vital signs, 19 Wound management, 396 Key words and terms are defined in the glossary on page 631. CHAPTER 6 / GENERAL MEDICINE 203 6 CARDIOPULMONARY Table 6.1 / Cardiopulmonary: Asthma and Brachycephalic Airway Syndrome Brachycephalic Airway Syndrome Definition Asthma and bronchitis are secondary to inflammation and airway disorders causing bronchoconstrictive episodes. The distress is often seen on expiration or as coughing fits. The causes may be allergic, bacterial, infection, pulmonary parasites, heartworm disease, or inhaled irritants. Brachycephalic breeds have a congenital condition of obstructive airways where the soft palate overlaps the tip of the epiglottis. Common contributing causes are stenotic nares and elongated soft palate; secondary everted laryngeal saccules are a sequela. Presenting Clinical Signs • Open-mouth breathing, coughing, wheezing, gagging, sneezing (v), dyspnea, vomiting, lethargy, and inappetance • Coughing, gagging, panting, open mouth breathing, dyspnea, tachypnea, change in voice, and exercise intolerance Examination Findings • Tracheal sensitivity, tachypnea, cyanosis, respiratory crackles, and tachy- or bradycardia • Stertor, stridor, and enlarged tonsils General • History/clinical signs • History/clinical signs • Airway examination Laboratory • • • • • Blood gas analysis Imaging • Radiographs, thoracic: pulmonary hyperinflation, aerophagia, flattened diaphragm, peribronchial or interstitial infiltration, atelectasis of middle lung or lung collapse, or pronounced bronchial pattern • Radiographs, cervical/pharyngeal: thickened and lengthened soft palate, and tracheal stenosis • Radiographs, thoracic: tracheal stenosis or aspiration pneumonia Procedures • ECG: heart disease screen • Bronchoscopy: tumors and airway pathology • Cytology, tracheal or bronchial wash: eosinophils, activated macrophages, nonregenerative neutrophils, bacteria, and parasites • Pulse oximetry • Laryngoscopy/pharyngoscopy: laryngeal and pharyngeal abnormalities • Tracheoscopy: location and severity of stenotic tracheal lesions and pharyngeal abnormalities General • Symptomatic • Oxygen therapy • Surgery: nasal wedge resection, laryngeal sacculectomy, or staphylectomy Medication • Anthelmintics: based on diagnosis or clinical signs and geographic location • Antibiotics: chloramphenical, clavamox, trimethoprim-sulfa, tetracycline, or quinolones • Bronchodilators: aminophylline, theophylline, terbutaline, or albuterol • Corticosteroids: prednisolone, dexamethasone • Corticosteroids (inhalers): fluticasone • Cyproheptadine • Leukotriene receptor blocker: zafirlukast • Sympathomimetic: epinephrine, isoproterenol, terbutaline, albuterol • No specific medications Nursing Care • Handle gently to avoid added stress. • Intensive monitoring postoperative for signs of airway collapse (e.g., vital signs) Diagnosis Presentation Asthma, Bronchitis, and Bronchopulmonary Disease (FBD) Treatment 6 Disease 204 CBC: neutrophilia, monocytosis (v) and eosinophilia (v) Fecal analysis: parasites (e.g., Paragonimus) Baermann technique: parasites (e.g., Aelurostrongylus) Heartworm tests: antigen and antibody SECTION THREE: DIAGNOSTIC SKILLS Table 6.1 / Cardiopulmonary: Asthma and Brachycephalic Airway Syndrome (Continued) Follow-Up Disease Asthma, Bronchitis, and Bronchopulmonary Disease (FBD) Brachycephalic Airway Syndrome Patient Care • Monitor clinical signs. • Monitor for several days postoperative for signs of aspiration while eating. • Do not encourage exercise and limit exercise in ↑ environmental temperatures. Prevention/ Avoidance • Early detection of recurrent infections • Eliminate any contributing environmental factors (e.g., cigarette smoke, air freshners, hair sprays, dirty furnace filters, or certain cat litters). • Maintain appropriate weight control. • Selective breeding Complications • Progression of disease • Bronchiectasis • Death from hypoxia during or following an anesthetic procedure • Incisional hemorrhage leading to laryngeal occlusion • Hyperthermia Prognosis • Guarded • Excellent with determination of environmental allergen • Fair • Guarded if severely affected Notes Client Education 6 • Caution: Endotracheal tubes should be left in place as long as possible following an anesthetic procedure to prevent tracheal occlusion. • Continue medication despite the disappearance of clinical signs. • Lifelong medication and environmental changes may be necessary. • Dogs should not be exercised extensively or in hot weather. Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic Disease Bronchitis (Canine) Cardiomyopathy, Hypertrophic Feline (Diastolic Dysfunction) Presentation Definition Presenting Clinical Signs Bronchitis is usually a progressive condition leading to permanent damage. Less frequently it can be acute with reversible damage. The causes include viral, bacterial, mycoplasma, infection, pulmonary parasites, heartworm disease, allergic, inhaled irritants, or foreign bodies. Hypertrophic cardiomyopathy is a disease that occurs independently of other cardiac diseases. It is characterized by concentric hypertrophy of the ventricular free wall and/or intraventricular septum. This leads to decreased ventricular compliance and ventricular diastolic dysfunction. • Cachexia, coughing, dyspnea, gagging, open mouth breathing, shortness of breath, tachypnea, wheezing, and exercise intolerance • Anorexia, collapse, constant crying, coughing, depression, dyspnea, hindlimb paralysis, hypothermia, inactivity, reluctance to move, pain, sudden death, tachypnea Examination Findings • Arrhythmias, cyanosis, dehydration, pyrexia, murmur, pulmonary crackles, syncope, tachycardia, tracheal sensitivity • Atrial gallop rhythm, cyanotic nailbeds and pads, femoral pulse weak, hindlimbs cold, muffled heart sounds, pleural effusion, pulmonary edema, systolic murmur, sinus tachycardia CHAPTER 6 / GENERAL MEDICINE 205 Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic (Continued) Disease Bronchitis (Canine) Cardiomyopathy, Hypertrophic General • History/clinical signs • Airway examination • History/clinical signs • Cardiac auscultation Laboratory • • • • • • • Blood gas analysis CBC: neutrophilia or moncytosis, eosinophilia, and ↑ PCV Chemistry panel: ↑ ALT and alk phos Urinalysis: ↑ specific gravity Fecal analysis: parasites Heartworm tests: microfilaria and adult antigen Cytology, transtracheal or bronchial wash: bacterial clusters, eosinophils, macrophages, neutrophils • Bacterial and fungal culture, transtracheal or bronchial wash: isolation and identification • Chemistry panel: ↑ CK, AST, ALT, and azotemia • Thyroid panel (T4, free T4, T3): ↑ in secondary cases due to primary hyperthyroidism Imaging • Radiographs, thoracic: normal in acute disease or ↑ cardiac size (v), ↑ interstitial density, aerophagia, peribronchial infiltrates, lung lobe atelectatic, flattening diaphragm, dilated airways, hyperinflation, or bronchial pattern • Echocardiogram: right heart enlargement and rule out congestive heart failure • Radiographs, thoracic: ↑ cardiac size, valentine-shaped heart, elongated heart shadow, LA enlargement, pulmonary edema, and pulmonary vein dilation • Echocardiogram: hypertrophy of the intraventricular septum, LV posterior wall, papillary muscles, left atrial enlargement, and hyperdynamic myocardium • MRI: identifying mild disease and assessing response to therapy Procedures • Bronchoscopy: sputum sample, tumor, inflammation, foreign bodies, and parasites • ECG: sinus arrhythmia, peaked P waves, and a wandering atrial pacemaker • ECG: sinus tachycardia, APCs, VPCs, ↑ P wave duration, ↑ R wave amplitudes, ↑ QRS width, atrial fibrillation • Blood pressure: hypotension General • Supportive • Oxygen therapy • • • • Symptomatic Fluid therapy Oxygen therapy Thoracocentesis Medication • Antibiotics: clavamox, trimethoprim-sulfa, cephalothin, enrofloxacin, or quinolones • Antitussives: hydrocodone or butorphanol • Bronchodilators: aminophylline, theophylline, or terbutaline • Corticosteroids: prednisone, dexamethasone • Corticosteroids (inhalers): fluticasone • Sympathomimetic: epinephrine, isoproterenol, terbutaline, albuterol • Tranquilizers • • • • • • • • • β-Blockers: propanolol or atenolol ACE inhibitor: enalapril Aspirin Bronchodilator: aminophylline Ca2+ channel blocker: diltiazem Diuretics: furosemide Sedation: acepromazine Vasodilator: nitroglycerin ointment, captopril Warfarin Nursing Care • Nebulization • Chest wall coupage • Heat support • Low stress environment • Restricted activity Treatment 6 Diagnosis Feline (Diastolic Dysfunction) 206 SECTION THREE: DIAGNOSTIC SKILLS Table 6.2 / Cardiopulmonary: Bronchitis and Cardiomyopathy, Hypertrophic (Continued) Disease Bronchitis (Canine) Cardiomyopathy, Hypertrophic Feline (Diastolic Dysfunction) • Weight loss • • • • • Prevention/ Avoidance • Maintain appropriate weight control. • Use a harness instead of a collar. • Eliminate any contributing environmental factors (e.g., cigarette smoke and dirty furnace filters). • Humidifier followed by light exercise to encourage expelling of sputum • Maintain oral health. • Heartworm prevention • Avoid stressful situations. Complications • • • • • • • • • • Prognosis • Good • Poor with irreversible changes from chronic bronchitis • Fair to good with some forms if diagnosed and treated early • Poor with progressive heart failure Notes • Caution: Equipment used (e.g., nebulizer) needs to be thoroughly cleaned to prevent bacteria contamination. • Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease • Pain and crying may indicate thromboembolism to posterior aortic branches. Client Education • • • • Follow-Up Patient Care Pneumonia Bacterial infection Bronchiectasis Syncope Observe closely for return of clinical signs Monitor blood values dependent on medical treatment chosen. Repeat echocardiogram after 4–6 months of initiating treatment. Sodium-restricted diet Warfarin use, monitor prothrombin time 6 Cardiac arrhythmias DIC Left heart failure Mitral valve regurgitation Sudden death Thromboembolism Harnesses should be used in place of collars. Weight loss may improve symptoms. Exercise assists in clearing airways, limit if results in coughing Dental care reduces secondary bacterial infections. CHAPTER 6 / GENERAL MEDICINE 207 Table 6.3 / Cardiopulmonary: Cardiomyopathy, Dilated Disease Canine Feline (Systolic Dysfunction) Dilated cardiomyopathy is a disease of the ventricular muscle. Advanced cases of disease show dilation of all chambers. Causes are typically idiopathic but have been linked in some cases to nutritional deficiencies, viral, protozoan, and immune-mediated mechanisms. Dilated cardiomyopathy is a disease of the ventricular muscle. Advanced cases of disease show dilation of all chambers. It is most commonly caused by taurine deficiency and is typically reversible. It can also be idiopathic, often the end stage of another disease. This disease leads to CHF or low cardiac output. Presenting Clinical Signs • Abdominal distention, anorexia, ascites, cachexia, collapse, coughing, dyspnea, exercise intolerance, syncope, tachypnea • Anorexia, constant crying, depression, dyspnea, inactivity, pain, posterior paresis, tachypnea, weakness, vomiting Primary Survey Findings • ↑ CRT, arrhythmias, atrial fibrillation, crackles, cyanosis, gallop, hepatomegaly, jugular pulse prominent, muffled heart and lung sounds, murmur, pleural effusion, pulmonary edema, pulse deficits, tachycardia, wheezes • Arrhythmia, ↑ CRT, crackles, femoral pulse weak or absent, hepatomegaly, hypothermia, jugular vein distention or prominent pulse, murmur, ocular fundus abnormalities, pallor, pleural effusion, pulmonary edema, pulse deficits, ↓ skin turgor, soft heart and lung sounds, summation gallop, tachy- or bradycardia, ventricular gallop General • History/clinical signs • Cardiac auscultation • Pulmonary auscultation • History/clinical signs • Cardiac auscultation • Pulmonary auscultation Laboratory • Chemistry panel: ↑ BUN, creatinine, ALT and ↓ sodium, chloride, potassium, protein • Plasma taurine and L-carnitine: ↓ • Blood gases: metabolic acidosis • CBC: leukocytosis, anemia, ↓ PCV: <18% • Chemistry panel: ↑ CK, AST, ALT, BUN, creatinine, glucose and ↓ potassium • Urinalysis: ↑ myoglobin • Plasma taurine: <40 nmoles/L • Pleural effusion analysis: TP <4.9 g/dL and nucleated cell count <2500/mL is supportive of diagnosis Imaging • Radiographs, thoracic: ↑ cardiac size, LA, LV, caudal vena cava enlargement, pleural effusion and pulmonary edema • Echocardiogram: chamber enlargement and speed of velocity and flow, reduced myocardial contractility • Radiographs, thoracic: ↑ cardiac size, rounding of cardiac apex, caudal vena cava and pulmonary veins enlarged, ascites, pleural effusion or pulmonary edema • Echocardiogram: anatomic abnormalities, dilation of LA and LV, ↓ LV contractility, valvular regurgitation, low aortic outflow velocity or LV muscle thinning • Angiocardiography: arterial thrombosis Procedures • ECG: atrial fibrillation, arrhythmias, low voltages (v), ↑ QRS duration, tachycardia, VPCs, and LV enlargement • ECG: arrhythmias, ↑ amplitude and duration of P waves, left atrial or ventricular enlargement patterns, sinus bradycardia (v), atrial fibrillation, VPCs Diagnosis Presentation Definition 6 208 Cardiomyopathy, Dilated SECTION THREE: DIAGNOSTIC SKILLS Table 6.3 / Cardiopulmonary: Cardiomyopathy, Dilated (Continued) Disease Canine Feline (Systolic Dysfunction) General • Symptomatic • Thoracocentesis (palliative) • • • • Symptomatic Fluid therapy Oxygen therapy Thoracocentesis Medication • • • • • • • • • • • • • • • • • • • • ACE inhibitor: enalapril, captopril Arterial dilators: hydralazine Aspirin Bronchodilator: aminophylline Diuretics: furosemide Positive inotropes: digoxin, dobutamine, milrinone Sedation: acepromazine Taurine supplementation Vasodilator: nitroglycerin ointment Treatment Follow-Up Cardiomyopathy, Dilated β-Blockers: sotalol ACE inhibitors: enalapril Aldsterone blocker: spironolactone Antiarrythymics: lidocaine, procainamide, mexiletine Bronchodilators: aminophylline Ca2+ channel blockers: diltiazem Diuretics: furosemide Inodilator: pimobendan Positive inotropes: digoxin and dobutamine Taurine or L-carnitine supplementation Vasodilator: nitroglycerin ointment 6 Nursing Care • Treated as outpatient • Heat support • Low stress environment • Nutritional support Patient Care • Monitor PE, radiographs, ECG, BP, and renal profile at regular intervals • Sodium-restricted diet • Restrict activity and limit exercise • • • • • Prevention/ Avoidance • N/A • Feed a high-quality diet with adequate taurine supplementation. Complications • Sudden death • Hypothyroidism • Hyperthyroidism • Thromboembolism Prognosis • Grave: 6–24 months following diagnosis • Good with taurine supplementation after survival of first 2 weeks. • Poor for idiopathic causes • Great Dane, Irish Wolfhound, Saint Bernard, Doberman Pinscher, Springer Spaniel, and Cocker Spaniel • Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease. • Pain and crying may indicate thromboembolism to posterior aortic branches. • Burmese, Abyssinian, and Siamese Notes Monitor taurine, electrolyte, and renal levels. Monitor blood values dependent on medical treatment chosen. Check thoracic radiographs after 1 week of initiating treatment. Repeat echocardiogram after 3–6 months of initiating treatment. Sodium-restricted diet CHAPTER 6 / GENERAL MEDICINE 209 Table 6.4 / Cardiopulmonary: Cardiomyopathy, Restrictive and Congenital Heart Disease Cardiomyopathy, Restrictive Feline (Diastolic Dysfunction) Congenital Heart Disease Definition Restrictive cardiomyopathy is a group of myocardial diseases that result in impaired ventricular filling. This impairment is unknown but might be caused by delayed myocardial relaxation or endocardial fibrosis. Congenital heart disease is the most common heart condition in animals <1 year of age. It is a malformation of the heart or great vessels. The following is a list of congenital heart defects: patent ductus arteriosus, pulmonic stenosis, subaortic stenosis, ventricular septal defect, atrial septal defect, mitral dysplasia, tricuspid dysplasia, and tetralogy of Fallot. Presenting Clinical Signs • Cachexia, depression, dyspnea, hypothermia, open mouth breathing, panting, tachypnea, crackles, pain, pleural effusion, posterior paresis or paralysis, pulmonary edema • Anoxia, dyspnea, exercise intolerance, stunted growth, seizures, syncope, tachypnea, weakness Examination Findings • Arrhythmia, ascites, crackles, cyanosis, gallop, jugular pulse distention, murmur, pleural effusion, pulmonary edema • Abdominal distention, cyanosis, murmur General • History/clinical signs • Cardiac auscultation • Pulmonary auscultation • History/clinical signs • Cardiac auscultation Laboratory • Chemistry panel: ↑ CK, AST, ALT, creatinine, potassium, and azotemia • Plasma taurine levels • CBC: ↑ PCV Imaging • Radiographs, thoracic: ↑ cardiac size, valentine-shaped heart, pleural effusion, pulmonary edema, pulmonary vein dilation, atrial and caudal vena cava enlargement • Echocardiogram: dilation of atria, LV or RV, myocardial fibrosis, myocardial hypertrophy in septum or LV, valvular regurgitation, altered or prominent papillary muscles • Angiocardiography: arterial thrombosis • Radiographs, thoracic: abnormalities in heart size and shape, major vessels and pulmonary vascularity; specific changes may vary with each defect/type • Echocardiogram: anatomic abnormalities, shunting lesion location and severity, and abnormal blood flow Procedures • ECG: arrhythmias, sinus tachycardia, atrial premature complexes, atrial fibrillation, ↑ amplitude and duration of P waves, or LA and LV enlargement patterns • ECG: ± chamber enlargement patterns General • • • • Symptomatic Fluid therapy Oxygen therapy Thoracocentesis/Pericardiocentesis • Supportive • Symptomatic • Surgery: dependent on defect Medication • • • • • • • • • β-Blockers: propanolol or atenolol ACE inhibitor: enalapril, captopril Antiarrhythmic: lidocaine Aspirin Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilator: nitroglycerin ointment Warfarin • • • • • • Presentation Disease Treatment Diagnosis 6 210 SECTION THREE: DIAGNOSTIC SKILLS β-Blockers: atenolol Antiarrhythmic: lidocaine or procainamide Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilators: enalapril Table 6.4 / Cardiopulmonary: Cardiomyopathy, Restrictive and Congenital Heart Disease (Continued) Follow-Up Treatment Disease Cardiomyopathy, Restrictive Feline (Diastolic Dysfunction) Congenital Heart Disease Nursing Care • • • • • • • Treated as outpatient until complications with chronic heart failure • Standard postoperative Patient Care • Reevaluate patients every 2–4 months. • Sodium-restricted diet • • • • • Prevention/ Avoidance • Avoid stressful situations • Selective breeding Complications • Thromboembolism • Chronic heart failure • Arrhythmias • Death Prognosis • Poor • Guarded without surgery Notes Heat support Low stress environment Restricted activity Reradiograph within 12–24 hours to monitor pleural effusion Monitor electrolytes daily for 3–5 days. Monitor hydration and renal profile. Monitor for clinical signs. Monitor PCV every 1–3 months. Monitor radiographs and echocardiograms at regular intervals. Restrict activity. Sodium-restricted diet 6 • Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease. • Pain and crying may indicate thromboembolism to posterior aortic branches. Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency) Heartworm Disease Definition Endocardiosis is the most common cardiovascular disease in dogs. It accounts for >75% of cases of congestive heart failure in dogs. The disease is an alteration in a structure of the mitral valve complex causing malfunction and progressive secondary cardiac changes, ultimately resulting in chronic heart failure. Heartworm disease is mostly a problem in dogs affecting most of the United States. It is an infection of Dirofilaria immitis transmitted by many species of mosquitoes. The worms reside in the pulmonary arteries and can extend into the right atrium and ventricle. Presenting Clinical Signs • Chronic small airway disease, congestion, cough, syncope, tachypnea, wheezing • Cachexia, cough, dyspnea, hemoptysis, syncope, vomiting (intermittent, feline), wheezes Examination Findings • Arrhythmias, cardiac tamponade, chronic small airway disease, crackles, cyanosis, muffled heart sounds, pleural effusion, pulse deficits, systolic murmur, tachycardia • Abnormal lung sounds, ascites, crackles, gallop, hypertension, murmur, organomegaly, tachycardia Presentation Disease CHAPTER 6 / GENERAL MEDICINE 211 Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease (Continued) Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency) Heartworm Disease General • History/clinical signs • Cardiac auscultation • Pulmonary auscultation • History/clinical signs • Cardiac auscultation Laboratory • Chemistry panel: ↑ BUN, creatinine, phosphorus, ALT, AST, alk phos, ↓ albumin • Urinalysis: ↑ protein, albumin, granular cast, WBC, occult blood • Culture, blood: + supportive of diagnosis • CBC: eosinophilia and basophilia (v) • Chemistry panel: ↑ hepatic enzymes, bile acids and ↓ albumin, globulin, azotemia • Urinalysis: ↑ protein, globulin, albumin, granular casts • ELISA: adult female worm antigens • Direct blood smear, Knott test or millipore filter test: microfilaria • Immunodiagnostic screens: microfilaria antigen • Serology: + dirofilaria Imaging • Radiographs, thoracic: ↑ cardiac size, pulmonary interstitial, alveolar congestion, pulmonary edema, alveolar edema, LA and LV enlargement, hilar lymphadenomegaly and anatomic changes in the LA, LV, and mainstem bronchi • Echocardiogram: anatomic changes, pleural and pericardial effusions, presence and severity of atrioventricular valve insufficiency with regurgitation, mitral valve abnormalities • Radiographs, thoracic: enlarged, truncated or tortuous arteries, R-sided cardiac enlargement, pneumonitis, or localized or generalized interstitial and/or alveolar infiltrates • Echocardiogram: RA, RV, and pulmonary artery enlargement, worm burden and severity of disease Procedures • ECG: recognition and identification of arrhythmia and ↑ P wave duration • ECG: arrhythmia, RV hypertrophy pattern or tall P waves General • Supportive • Symptomatic • Oxygen therapy • Supportive • Platelet count Medication • • • • • • • • • • • • Nursing Care • Low stress environment Treatment 6 Diagnosis Disease 212 ACE inhibitor: enalapril Adrenergic blocking agent: prazosin Antibiotics: penicillin,gentamicin, enrofloxacin, amoxicillin Arterial dilators: hydralazine Ca2+ channel blocker: diltiazem Diuretics: furosemide Positive inotropes: digoxin Vasodilator: nitroglycerin ointment SECTION THREE: DIAGNOSTIC SKILLS Adulticide: thiacetarsamide sodium or melarsamine Aspirin (low-dose) Corticosteroids: prednisone or prednisolone (cats) Larvacide: ivermectin or milbemycin • Feed patient 1/2 hour prior to injection to observe for anorexia • Monitor for jaundice, fever, depression, dyspnea or other signs of thromboembolism • Close monitoring after administering injection for signs of toxicity (inflammation at injection site, vomiting, anorexia, lethargy, icterus, and ↑ BUN, ALT, or bilirubin Table 6.5 / Cardiopulmonary: Endocardiosis and Heartworm Disease (Continued) Follow-Up Disease Endocardiosis (Chronic Valvular Heart Disease, Chronic Mitral Valve Insufficiency) Heartworm Disease Patient Care • Monitor BUN and creatinine when using diuretics and ACE inhibitors. • Monitor PE, ECG, and radiography 1 week after initiating therapy. • Monitor blood cultures and echocardiogram following antibiotic therapy. • Monitor cardiomegaly through radiographs every 6–12 months. • Restrict activity. • Sodium-restricted diet • Monitor for jaundice, fever, depression, dyspnea or other signs of thromboembolism. • Strict confinement for 4–6 weeks • Start larvacide treatment 4 weeks post-adulticidal treatment. • Retest for microfilaria 7 weeks post-adulticidal treatment. Prevention/ Avoidance • N/A • Prophylactic therapy: milbemycin oxide • Heartworm surveillance testing: 6–12 months of initiating preventative and then at regular intervals Complications • • • • • • • • • • • • • Prognosis • Dependent of severity of disease • Good when subclinical or mild disease • Fair with moderate to severe disease • Guarded if untreated or very high worm burden • Poodle, Yorkshire Terrier, Cavalier King Charles Spaniel, Schnauzer, Cocker Spaniel • Caution: Very high mortality in felines when thiacetarsamide therapy is used. • Caution: IM injection can cause pain and sterile abscesses with melarsamine. • Each injection is given in a peripheral vein at a different location as distal as possible with thiacetarsamide sodium. • Indwelling catheters are not recommended for administration. Notes Atrial fibrillation Death LA rupture Pulmonary and systemic emboli Right-sided heart failure Tachyarrhythmia Tamponade Toxemia 6 DIC Thrombocytopenia Heart failure Acute pulmonary thromboembolism Thiacetarsamide sodium toxicity CHAPTER 6 / GENERAL MEDICINE 213 Table 6.6 / Cardiopulmonary: Congestive Heart Failure Disease Congestive Heart Failure Left-Sided Diagnosis 214 Heart failure is the failure of the left or right side of the heart to adequately pump blood through the body or through the pulmonary circulation respectively. The causes of congestive heart failure may be mechanical failure (valve insufficiency, aortic regurgitation or hypertension), myocardial failure (myocarditis, dilated cardiomyopathy or neoplasia), interference with cardiac filling (severe arrhythmia, hypertrophic cardiomyopathy or tamponade) or increased requirement for cardiac output (anemia, overexercise, pregnancy or hyperthyroidism). Presenting Clinical Signs • Cachexia, cough, dyspnea, hemoptysis, limb swelling, syncope, tachypnea, wheezes • Cachexia, pallor, syncope Examination Findings • Arrhythmias, ascites, crackles, cyanosis, ↑ CRT, femoral pulses weak, gallop, murmur, organomegaly, pallor, pulmonary edema, pulse deficit, weak, pounding or irregular • Arrhythmia, ascites, gallop, jugular vein distention, muffled heart sounds, murmur, organomegaly, pericardial effusion, pleural effusion, subcutaneous edema, system venous congestion General • History/clinical signs • Cardiac auscultation Laboratory • Chemistry panel: ↑ ALT, AST, alk phos, BUN, creatinine and ↓ sodium, potassium, protein • Heartworm tests: microfilaria and adult antigen • CBC: eosinophilia (v) • Chemistry panel: ↑ ALT, AST, alk phos, GGT, BUN, creatinine, ↓ sodium, potassium, protein Imaging • Radiographs, thoracic: ↑ cardiac size, systemic or pulmonary venous dilation, pulmonary edema, or hilar lymphadenomegaly • Echocardiogram: cause and extent of disease, pericardial or pleural effusion, neoplasia, or heartworm disease • Radiographs, thoracic: ↑ cardiac size, distended vena cava, pleural effusion and/or ascites, pulmonary edema, enlarged pulmonary arteries Procedures • ECG: arrhythmias, wide (and tall if R-sided) P waves, tall and wide QRS complexes and left axis orientation General • • • • • Symptomatic Fluid therapy Oxygen therapy Thoracocentesis/pericardiocentesis/abdominocentesis, as needed Dependent on underlying condition Medication • • • • • • • • • • • β-Blockers: propanolol, atenolol, or metoprolol ACE inhibitors: enalapril or captopril Arterial dilators: hydralazine Ca2+ channel blockers: diltiazem, amlodipine Diuretics: furosemide Inodilator: pimobendan Positive inotropes: digoxin, dobutamine or dopamine Sedation: morphine sulfate, acepromazine maleate Sodium nitroprusside Taurine supplementation Venodilators: nitroglycerin ointment Nursing Care Restrict stress: handling only for extremely necessary procedures Treatment 6 Presentation Definition Right-Sided SECTION THREE: DIAGNOSTIC SKILLS • • • • ACE inhibitors: enalapril or captopril Ca2+ channel blocker: amlodipine Diuretics: furosemide Positive inotropes: digoxin Table 6.6 / Cardiopulmonary: Congestive Heart Failure (Continued) Disease Congestive Heart Failure Follow-Up Left-Sided Restrict activity and ↓ anxiety Monitor ECG, echocardiogram, serum chemistries and serum digoxin concentrations regularly Monitor resting respiratory rate (normal: <30 breaths/min) Sodium-restricted diet Patient Care • • • • Prevention/ Avoidance • Minimize stress and exercise. Complications • • • • • • • Prognosis Notes Right-Sided Aortic thromboembolism (feline) Arrhythmias Electrolyte imbalances Digoxin toxicity Renal failure Hypertension Muscle wasting 6 • Dependent on underlying disease • Caution: Aggressive fluid therapy must be monitored closely for overload and worsening disease. Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis Hypertension Myocarditis Definition Hypertension is an increase in pulmonary arterial or systemic blood pressure. It may be either a primary or secondary condition. Systemic hypertension is diagnosed through Doppler, whereas pulmonary arterial hypertension is found through cardiac catheterization. Myocarditis is an inflammation of the heart muscle. Some causes are: infectious, viral, protozoan, ischemic injury, trauma, or toxicity. Primary infection is rare; typically, it is secondary to another disease process. Presenting Clinical Signs • Dependent on underlying condition • Anorexia, ataxia, blindness, circling, diarrhea, dilated pupils, disorientation, dyspnea, exercise intolerance, hemoptysis, hindleg paresis, ocular hemorrhage, PU/PD, seizures, tachypnea, vomiting • Cough, fever, exercise intolerance, syncope, weakness Examination Findings • Abnormal heart and lung sounds, ascites, atrial gallop, crackles, cyanosis, edema, hypoxemia, retinal detachment, systolic murmur • Arrhythmias, gallop, murmur, VPCs, ventricular tachycardia Presentation Disease CHAPTER 6 / GENERAL MEDICINE 215 Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis (Continued) Diagnosis Disease Hypertension Myocarditis General • History/clinical signs • History/clinical signs (e.g., parvovirus, Chagas disease) • Cardiac auscultation Laboratory • CBC: neutrophilia and lymphopenia (v), thrombocytopenia, leukopenia, and ↑ PCV • Chemistry panel: ↑ phosphorus, ALT, cholesterol, BUN, creatinine, glucose, alk phos and ↓ albumin and electrolyte imbalances • Urinalysis: ↑ protein, blood, glucose and ↓ specific gravity with renal dysfunction • Chemistry panel: ↑ CK, LDH, AST • Serology, parvovirus, toxoplasmosis, trypanosomiasis: + Imaging • Radiographs, thoracic: ↑ cardiac size, ↑ density, pulmonary artery dilation, ascites, neoplasia, bronchial collapse, tracheal narrowing • Radiographs, abdominal: hepatomegaly or abnormal kidneys • Echocardiogram: pulmonary hypertension, right heart dilation • Ultrasound: adrenal enlargement • Radiographs, thoracic: pulmonary edema, congestion, pleural effusion, ↑ cardiac silhouette or rounded heart shape • Echocardiogram: pericardial effusion, thickened pericardium or mottled and patchy areas on myocardium • Angiogram: specific chamber involvement or pleural effusion Procedures • Blood pressure: systemic hypertension • Pulmonary catheterization: pulmonary hypertension (invasive measurement) • ECG: arrhythmias and enlargement patterns General Only for Complicated Disease • Supportive • Fluid therapy • Oxygen therapy • Supportive • Pericardiocentesis Medication • • • • • • Nursing Care • Treat as outpatient if possible to ↓ overall stress. • Restrict activity Patient Care • Sodium-restricted diet • Monitor for signs of hypotension. • Monitor blood pressure every 1–2 weeks, then every 1–3 months. • Sodium-restricted diet • Monitor ECG and auscultation. • Reradiograph Prevention/ Avoidance • Maintain proper weight control. • Measure BP in all renal failure patients. • Vaccinate. • Monitor ECG and echocardiogram with patients using doxorubicin. • Avoid endemic areas (e.g., Gulf Coast). Follow-Up Treatment 6 216 α-Adrenergic blocker: prazosin β-Adrenergic blocker: propranolol ACE inhibitor: enalapril Ca2+ channel blocker: diltiazem or amlodipine (cats) Diuretics: furosemide Hydralazine SECTION THREE: DIAGNOSTIC SKILLS Dependent on underlying condition • ACE inhibitor: enalapril • Antiarrhythmics: quinidine • Diuretics: furosemide • Positive inotropes: digoxin Table 6.7 / Cardiopulmonary: Hypertension and Myocarditis (Continued) Hypertension Myocarditis Complications • • • • • • Cardiomyopathy • Chronic heart failure Prognosis • Good if underlying cause can be determined and treated Follow-Up Disease Notes Renal failure Chronic heart failure Glomerulonephropathy Retinopathy/blindness CNS signs • Dependent on extent and severity of disease Canine Abnormal Systemic Values • Systolic: >160 mm Hg • Diastolic: >100 mm Hg Feline Abnormal Systemic Values • Systolic: >160 mm Hg • Diastolic: >120 mm Hg • An average of 3 readings should be done to adequately evaluate a patient’s blood pressure. • Avoid use of PPA. • Maintain low stress before and during the BP measurement. 6 Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion Pneumonia Pleural Effusion Definition Pneumonia is an inflammatory response of the lungs. It is most commonly caused by bacteria but can also be caused by aspiration of ingesta, fungi, allergic, foreign body, viral, neoplasia, lung parasites, or contusions. It has a high rate of mortality and morbidity, especially in hospitalized animals. Pleural effusion is an accumulation of fluid in the pleural cavity. It may be seen unilateral or bilateral. This is an abnormal process that has many causes, typically indicating a more severe underlying condition. Presenting Clinical Signs • Cachexia, dyspnea, mucopurulent nasal discharge, productive cough, tachypnea, wheezes • Anorexia, depression, dyspnea, exercise intolerance, pallor, pleuritis, open-mouth breathing, preference for sternal recumbency, tachypnea Examination Findings • Crackles, cyanosis, dehydration, pyrexia, loud or asymmetric bronchial sounds, tachycardia • Ascites, cyanosis, pyrexia, muffled heart and lung sounds, tachycardia General • History/clinical signs • Pulmonary auscultation • • • • Diagnosis Presentation Disease History/clinical signs Cardiac auscultation Pulmonary auscultation Thoracic palpation and percussion CHAPTER 6 / GENERAL MEDICINE 217 Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion (Continued) Diagnosis Disease Follow-Up Treatment 6 218 Pneumonia Pleural Effusion Laboratory • CBC: neutrophilic leukocytosis with or without a left shift and monocytosis • Cytology, tracheal wash: ↑ neutrophils and bacteria • Culture, tracheal wash: bacteria isolation and identification • • • • Imaging • Radiographs, thoracic: ↑ lung density, lung consolidation, pulmonary artery enlargement, or interstitial pattern with air bronchograms • Contrast study: swallowing disorders • Radiographs, thoracic: ↑ cardiac size, tumor, lung lobe torsion, diaphragmatic hernia, widening of mediastinum, rounded lung lobe edges, obscured cardiac borders and diaphragm, ascites, and pleural fissure lines • Contrast study: tumor, diaphragmatic hernia, and cardiac disease Procedures • Bronchoscopy: foreign body or neutrophilic inflammation • ECG: amplitudes all depressed General • • • • • • • • • Medication • Antibiotics: dependent on type of bacteria isolated and one with good penetration into lung tissue (e.g., enrofloxacin) • Antifungal: amphotericin, flucytosine, ketaconazole, fluconazole • Bronchodilators: theophylline or terbutaline • Antibiotics: dependent on type of bacteria isolated • Analgesics: bupivacaine, NSAIDs, morphine, meperidine Nursing Care • • • • • • • Monitor temperature, respiratory rate and effort and pulse • Nutritional support • Chest tube management Patient Care • Airway humidification • Mild exercise • Reradiograph in 48–72 hours, then after 2–6 weeks • Monitor radiographs Prevention/ Avoidance • Vaccinate • N/A Complications • Chronic bronchitis • Secondary infection/sepsis • Death Prognosis • Good • Guarded to poor Supportive Fluid therapy Oxygen therapy Surgery: lung lobectomy (rare) Nebulization with bland aerosols Chest wall coupage Tracheal manipulation Restrict activity Alter patient’s position at least every 2 hours Nutritional support SECTION THREE: DIAGNOSTIC SKILLS CBC: leukocytosis and anemia Chemistry panel: ↑ globulin and ↓ albumin: <1 g/dL Serology: FeLV, FIP, FIV, or heartworm Fluid analysis: color, clarity, viscosity, specific gravity, TP, and nucleated cell count, neutrophils, macrophages, mesothelial cells, lymphocytes, eosinophils, or neoplastic cells Symptomatic Fluid therapy Thoracocentesis Chest tube placement Surgery: thoracotomy Table 6.8 / Cardiomyopathy: Pneumonia and Pleural Effusion (Continued) Disease Pneumonia Notes Pleural Effusion • Classification of fluids: • Colorless to pale yellow: transudate • Yellow to pink: modified transudate or nonseptic exudate • Yellow to red-brown: septic exudate • Milky white: chylous • Red: hemorrhage • Pain medication may be directly injected through the chest tube to give pleural analgesia. 6 Table 6.9 / Cardiopulmonary: Rhinitis/Sinusitis and Tracheal Collapse Rhinitis/Sinusitis Tracheal Collapse Definition Infection of the nasal sinuses is a common veterinary problem. There is acute rhinitis, which is self-limiting, and chronic sinusitis, which may require constant treatment. The causes are bacterial, viral, fungi, foreign body, dental disease, infectious agents, or neoplasia. A collapsing trachea is a trachea with a range of dynamic variations resulting in collapse somewhere along its length. It may also involve the mainstem bronchi causing them to collapse also. It can be an acquired weakness or congenital defect. It is most commonly seen in older toy breed dogs. Presenting Clinical Signs • Cough, gagging, mucopurulent nasal discharge, ocular discharge, open mouth breathing, retching, sneezing • Cachexia, change in voice, dyspnea, gagging, heat intolerance, intermittent “honking” cough, syncope Examination Findings • Bony swelling, pyrexia, lymphadenopathy, oral ulceration, ocular or neurological changes • Cyanosis, enlarged tonsils, stertor, stridor General • History/clinical signs • Nasal examination • History/clinical signs • Airway examination Laboratory • Cytology and culture: bacteria recognition and identification • Fungal culture: isolation and identification • N/A Imaging • Radiographs, skull: ↑ fluid and bony changes (e.g., loss of bone detail and deviated septum) • Radiographs, thoracic: narrowing or ballooning of tracheal diameter and ↑ R-sided cardiac size • Radiographs, cervical/pharyngeal: narrowing or ballooning of tracheal diameter Procedures • Rhinoscopy: foreign body and bony changes • Biopsy: bacteria or fungi • Bronchoscopy: severity and small airway disease • Fluoroscopy: narrowing of tracheal diameter may be dynamic General • • • • • Symptomatic • Surgery: application of intraluminal or extraluminal prostheses Treatment Diagnosis Presentation Disease Supportive Fluid therapy Radiotherapy Surgery: nasal exploratory, rhinotomy, or turbinectomy CHAPTER 6 / GENERAL MEDICINE 219 Table 6.9 / Cardiopulmonary: Rhinitis/Sinusitis and Tracheal Collapse (Continued) Rhinitis/Sinusitis Tracheal Collapse Medication • Antibiotics: cephalexin, trimethoprim-sulfa, and chloramphenical • Corticosteroids: prednisone • Fungicides: enilconazole, itraconazole, thiabendazole, or ketoconazole • Antitussives: butorphanol, hydrocodone • Bronchodilators: aminophylline, theophylline, terbutaline, guaifenesin • Corticosteroids: prednisone Nursing Care • Airway humidification • Intensive monitoring during and postoperative for signs of hypoxia Patient Care • Monitor for relapse of clinical signs • Limit activity • Weight loss • Chest harness Prevention/ Avoidance • Vaccinate • Maintain good oral hygiene • Prevent exposure to bird feces (aspergillosis and cryptococcosis) • Maintain proper weight control • Avoid extreme temperature and humidity changes Complications • Brain infection • Epistaxis • Death from hypoxia (rare) Prognosis • Fair to good • Good with uncomplicated surgery • Guarded with symptomatic treatment • Serous nasal discharge is indicative of acute or allergic disease • Mucopurulent discharge suggests bacterial or fungal infection (infection may be only secondary to underlying neoplasia) • Obtain both inspiratory and expiratory radiographs: tracheal collapse may be seen at any point during breathing Notes DERMATOLOGY Table 6.10 / Dermatology: Acne Disease Definition Presentation 6 Follow-Up Treatment Disease 220 Presenting Clinical Signs Acne Canine Feline Chronic inflammatory disorder most often seen in short-coated breeds. It is often associated with superficial and deep pyoderma. It is typically found on the chin and lips of young animals. Feline acne is often associated with the chin and lower lip. They may have a single episode or a continual lifelong problem. Poor grooming is thought to be one cause for this condition. • Erythematous papules, swelling, exudate and scarring • Comedones, erythema papules, serous crusts, swelling, and alopecia SECTION THREE: DIAGNOSTIC SKILLS Table 6.10 / Dermatology: Acne (Continued) Follow-Up Treatment Diagnosis Disease Acne Canine Feline General • Clinical signs • Clinical signs Laboratory • Culture, bacterial: bacteria isolation and identification • N/A Imaging • N/A • N/A Procedures • Biopsy: to confirm diagnosis • Biopsy: to confirm diagnosis General • Symptomatic • Skin treatment • Symptomatic • Skin treatment Medication • Antibiotics: cephalexin, clavamox, clindamycin, erythromycin, cefpodoxime • Antibiotics (topical): mupirocin • Corticosteroids: prednisone or prednisolone • Medicated gels: pyoben • Medicated shampoo: benzoyl peroxide • Retinoids (topical): retin-A gel and tretinoin • • • • Nursing Care • Treated as outpatient • Treated as outpatient Patient Care • Prevent self-trauma: (e.g., rubbing of chin, chewing on bones that ↑ salivation). • Frequent cleaning/shampooing of chin • Warm compresses • Shampoo 1–2 times weekly and then taper over a 2–3 week period. • Monitor PE and chemistry panel monthly with retinol. Prevention/ Avoidance • Maintenance lifelong treatment may be necessary. • Maintenance lifelong treatment may be necessary. • Avoid the use of plastic feeding dishes. Complications • Deep pyoderma • Deep pyoderma Prognosis • Excellent • Excellent • English Bulldog, Boxer, Doberman Pinscher, and Great Dane • Discourage owners from expressing the lesions, it can lead to massive inflammation. • Discourage owners from expressing the lesions, it can lead to massive inflammation. Notes Antibiotics: clavamox or enrofloxacin Antibiotics (topical): mupirocin Medicated shampoo: benzoyl peroxide or sulfur–salicylic acid Retinoids (topical): retin-A gel and tretinoin CHAPTER 6 / GENERAL MEDICINE 6 221 Table 6.11 / Dermatology: Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis Disease Acral Lick Dermatitis (Lick Granuloma, Acral Pruritic Nodule) Atopy Flea Allergy Dermatitis (FAD) Definition Acral lick dermatitis is an area of a firm, raised, ulcerative, or thickened area that is usually located on the dorsal aspect of the carpus, metacarpus, tarsus, or metatarsus. The area may have a history of trauma, foreign body reaction, neoplasia, allergy, endocrinology, or others. The problem is typically made worse by the constant licking and chewing by the patient. Animals that have formed allergies to normally innocuous inhaled substances such as pollen, grass, fleas, molds, and mites. This disease is the cause of a majority of dermatologic problems. The antigens in the saliva of fleas are the cause of a hypersensitivity reaction called flea allergy dermatitis. It is the most common skin disease in most geographical areas, especially during the summer months. Ctenocephalides felis is the type of flea that usually infests both dogs and cats. Presenting Clinical Signs • Alopecia, excessive licking, chewing • Pruritis and skin lesions • Canine: alopecia, edema, face rubbing, foot chewing, hyperpigmentation • Feline: alopecia, dermatitis, and miliary eczema • Alopecia (tail base, dorsal lumbar region, caudal thighs, groin, abdomen, head and neck), broken hairs, chewing, dry hair, excoriations, hyperpigmentation, licking, pruritis, rolling, rubbing, scaling, scratching • Feline: alopecia (head and neck) Examination Findings • Firm, hyperpigmentation, raised, thickened, ulcerative • Canine: otitis externa, recurrent pyoderma, seborrheic dermatitis • Feline: miliary eczema, eosinophilic granuloma complex • Erythema, otitis externa, papules • Feline: lymphadenopathy, miliary eczema General • History/clinical signs • History/clinical signs: seasonal • History/clinical signs • Presence of fleas or flea dirt Laboratory • Skin scraping: bacteria, demodex, dermatophytosis • Culture, bacterial: bacteria isolation and identification • Biopsy, skin: neoplasia • Intradermal skin test: atopy • CBC: eosinophilia (occasional) • Intradermal skin test: most reliable specific test • ELISA and RAST: ↑ values (nonspecific) • CBC: hypereosinophilia (cats–v) • Intradermal skin test: + (reliable) • Serology: + serum IgE anti-flea antibody titer Imaging • Lower limb: neoplasia, radiopaque foreign body, bony proliferation, and some forms of trauma • N/A • N/A Procedures • Hypoallergenic test diet: food hypersensitivity Diagnosis Presentation 6 222 SECTION THREE: DIAGNOSTIC SKILLS • Flea combing Table 6.11 / Dermatology: Acral Lick Dermatitis, Atopy, and Flea Allergy Dermatitis (Continued) Acral Lick Dermatitis (Lick Granuloma, Acral Pruritic Nodule) Atopy Flea Allergy Dermatitis (FAD) General • Symptomatic • Laser ablation • Symptomatic • Symptomatic Medication • Antihistamines: chlorpheniramine and hydroxyzine HCl • Antibiotics: variable • Psychotropic drugs: clomopramine HCl, amitriptyline or fluoxetine HCl • Antihistamines: chlorpheniramine, hydroxyzine and diphenhydramine • Corticosteroids: prednisone or methylprednisolone • Cyclosporine • Immunotherapy: SQ injection of increasing doses of offending allergen • Medicated shampoos • Psychotropic agents: amitriptyline, fluoxetine, barbiturates • Antihistamines: diphenhydramine or chlorpheniramine • Antiparasitic: fipronil • Corticosteroids: triamcinolone • Fatty acid supplements • Insecticide: imidacloprid and selamectin • Insect growth regulator: lufenuron, pyriproxifen, methoprene Follow-Up Treatment Disease 6 Nursing Care • Treated as outpatient • Treated as outpatient • Treated as outpatient Patient Care • Monitor close for licking and chewing. • Check CBC, biochemistry, and ECG every 1–2 months for those receiving tricyclic antidepressants. • Fatty acid supplementation • Frequent bathing to reduce pruritis • Exam patients 2–8 weeks following treatment, then every 3–12 months. • Flea comb regularly. Prevention/ Avoidance • Determine underlying disease when possible. • Avoid offending allergen. • Maintain year around flea control: flea comb, monthly oral medication, and/or spot-on medication. Complications • Deep pyoderma • Superficial pyoderma • Flea allergy dermatitis • Surface pyoderma • Superficial or deep pyoderma • Acute moist dermatitis • Acral lick dermatitis Prognosis • Guarded (not life threatening) if no underlying disease is found and psychogenic causes are suspected • Good if allergen is determined • Excellent • Elizabethan collars, foul-tasting medications and sprays, and bandages may be used to prevent licking and chewing. • Additional attention and exercise may help if psychogenic causes are suspected. • Do not use penicillins or tetracyclines for treatment of superficial pyoderma. • Some type of treatment is usually needed for life. • It may take up to 6–12 months before results from immunotherapy are seen. • A complete flea control plan includes treating the pet, other pets in-household, and indoor and outdoor environment. • Control may take 4–8 weeks to achieve. • With many new alternatives to flea control, dips, sprays, and flea collars should be the last choice for control. • Extra care should be taken when using insecticides to avoid overdose to animals and humans. • Flea-infested animals should also be checked for Dipylidium caninum. Notes CHAPTER 6 / GENERAL MEDICINE 223 Table 6.12 / Dermatology: Food Hypersensitivity and Otitis Externa Food Hypersensitivity Otitis Externa Definition Food hypersensitivities show symptoms induced by food or food additive ingestion in which there are demonstrable or highly suspected immunologic reactions. Otitis externa is the inflammation of the soft tissue of the external ear canal. Its causes are often multifactorial, signifying a generalized dermatologic problem. It can be either a primary or a secondary disease, making it very frustrating and difficult to treat. Presenting Clinical Signs • Alopecia, diarrhea, flatulence, pruritis (feet, ears, face, neck, inguinal or axillary areas, perineum), seizures, vomiting • Behavioral changes (irritable, aggression), foul odor, head shaking, head tilting, hearing loss, pain, foul odor, scratching, rubbing at ears Examination Findings • Erythematous, otitis externa, Malassezia dermatitis, papular rash • Calcification/thickening of canal, debris, exudate, inflammation, swelling, ulceration General • History/clinical signs • Nonseasonal occurrence and partial or incomplete response to corticosteroids • History/clinical signs • Otoscopic examination Laboratory • N/A • N/A Imaging • N/A • Radiographs, skull: only used in chronic cases to determine patency of ear canal and rule out otitis media Procedures • Intradermal skin testing: inconsistent findings • Hypoallergenic test diet or novel elimination diet trial • Cytology: parasites, cells, bacteria, yeast, and fungi • Culture: bacteria recognition and identification • Intradermal skin tests: + results General • Symptomatic • Symptomatic • Flush and dry ear canals; Tris-EDTA as pretreatment wash Medication • If any, dependent on clinical signs • Antibiotics: cephalexin, trimethoprim-sulfa, enrofloxacin, clindamycin, clavamox, ciprofloxacin, difloxacin, cefpodoxime • Antibiotics (topical): enrofloxacin, tobramycin, silver sulfadiazine • Antifungals: ketoconazole, miconazole • Corticosteroids: prednisone • Ear cleaner • Parasiticides: ivermectin Nursing Care • Treated as outpatient • Treated as outpatient Patient Care • Feed the restricted diet exclusively for 10–12 weeks. • Avoid flavored chew toys, bones, treats, vitamins and medications. • Recheck ears frequently until resolved: do not treat prior to examination for better visibility. Prevention/ Avoidance • Restrict the feeding of hypersensitive foods. • Clean ears regularly. • Thoroughly dry ears after swimming and bathing. • Lateral ear resection surgery Complications • Pruritis: by other sources • Ruptured ear drum • Otitis media • Permanent ear canal changes: stenosis and calcification Prognosis • Good if offending food is determined • Excellent if treated early Presentation Disease Follow-Up Treatment Diagnosis 6 224 SECTION THREE: DIAGNOSTIC SKILLS Table 6.12 / Dermatology: Food Hypersensitivity and Otitis Externa (Continued) Disease Food Hypersensitivity Otitis Externa Notes • The diet should consist of foods that the animal has not been previously exposed to (e.g., rice, potatoes, lamb) and without additives or preservatives. (See Table 3.2 Disease Nutritional Requirements, page 64.) • If no improvement, review other food sources and other forms of allergens (e.g., fleas and inhalant). • Corticosteroids should only be used with severe pruritis; otherwise, they may alter the results of the hypoallergenic diet test. • Enough topical medication must be used to coat the entire ear canal for effectiveness, and then its use is tapered once infection is resolved. • Possible reasons for certain exudates: • Dark, dry, and granular: ear mite infection • Moist, yellow, and odiferous: bacterial infection • Brown and waxy: yeast infection • Yellow and waxy-to-oily: keratinization disorders • Use only warmed 0.9% saline to flush an ear canal with a ruptured tympanic membrane. • Plucking hair from within the ear canal may cause irritation and predisposes the animal to otitis externa. 6 Table 6.13 / Dermatology: Pyoderma Disease Definition Presentation Presenting Clinical Signs Examination Findings Pyoderma Deep Superficial (Superficial Bacterial Folliculitis) Surface (Acute Moist Dermatitis [Hot Spots], Skinfold Dermatitis) Deep pyoderma extends into the dermis and, in severe cases, into the subcutaneous tissue. This bacterial skin infection has many different forms, two of the most common being folliculitis and furunculosis. It is almost always secondary to another disease process. The epidermis is the target of a bacterial infection with superficial pyoderma. It can manifest itself in 2 ways: penetrating the stratus corneum (impetigo) or invading the hair follicles (folliculitis). Self-trauma and deep skinfolds are the most common reasons for surface pyoderma. This is due to a colony of bacteria on the surface of the epidermis only, without invading the stratum corneum or hair follicles. Acute moist dermatitis (hot spots) and skinfold dermatitis are the two distinct forms of surface pyoderma. • Alopecia, anorexia, depression, peripheral lymphadenopathy, and fever • Pustules: inguinal, ventral abdominal, and axillary areas extending to the whole body • Erythematous, painful, pruritic skin • Exudate and crust formation, drainage tracts, and hemorrhagic bullae • Dull haircoat, excessive shedding, scales • Impetigo: pustules (inguinal and ventral abdominal area, esp. young animals), patchy alopecia • Folliculitis: pustules (inguinal, ventral abdominal, axillary areas) • Biting, licking, and rubbing by patient Acute Moist Dermatitis • Alopecia, thin exudate layer, erythema, surrounded by matted hairs and thickened skin with abrasion Skinfold Pyoderma • Inflammation, exudate, fetid, alopecia, and erythema • Folliculitis: epidermal collarettes (“bull’seye” lesions), erythema, pruritic skin CHAPTER 6 / GENERAL MEDICINE 225 Table 6.13 / Dermatology: Pyoderma (Continued) Disease Superficial (Superficial Bacterial Folliculitis) Surface (Acute Moist Dermatitis [Hot Spots], Skinfold Dermatitis) General • History/clinical signs • History/clinical signs • History/clinical signs • Self-trauma, environmental irritant, or any pruritic skin Laboratory • • • • • • • • Cytology: neutrophils and bacteria • Skin scrapings: ectoparasites • Culture: bacteria isolation and identification • Skin biopsy: to confirm folliculitis • Culture: bacteria isolation and identification • Skin biopsy: nonfollicular subcorneal pustules, suppurative inflammation with sepsis • Skin Scraping: cocci in clusters on squamous epithelial cells or budding yeast Imaging • N/A • N/A • N/A Procedures • Skin scraping and biopsy • Skin scraping and biopsy • N/A General • Symptomatic • Fluid therapy (severe cases) • Symptomatic • Symptomatic • Wound management Medication • Antibiotics: variable • Medicated shampoos • Antibiotics: variable • Medicated shampoos: antibacterial • Antibiotics (oral and/or topical): variable • Corticosteroids (topical): panalog cream and neopredef powder Nursing Care • Clip haircoat on long-coated breeds • Treated as outpatient • Treated as outpatient Patient Care • Bathe twice daily for 1–2 weeks then 1–2 times weekly. • Whirlpool baths • Provide a high-quality diet. • Supplement with essential fatty acids. • Padded bedding to ease pressure point pyoderma • • • • • Maintain a clean and dry wound • Prevent self-trauma: restraint, collars, etc. Prevention/ Avoidance • Determine the underlying cause. • Bathe regularly with appropriate shampoo. • Determine the underlying cause. • Bath with appropriate shampoo, especially after swimming. • Determine the underlying cause. • Clean and dry the skinfolds routinely with astringents. Complications • Bacteremia or septicemia • Scarring • Deep pyoderma • Recurrence • Superficial or deep pyoderma Prognosis • Excellent if underlying cause is determined • Excellent • Excellent • German Shepard • If persistent pruritis, ectoparasitism or allergy may be present as underlying etiology. • Cocker Spaniel, Springer Spaniel, Saint Bernard, Irish Setter, Shar pei, Basset Hound, Bulldog, Boston Terrier, and Pug • Corrective surgery may be performed on chronically infected skinfolds. Diagnosis Deep Follow-Up Treatment 6 Notes 226 Pyoderma CBC: leukocytosis with a left shift (v) Chemistry panel: ↑ globulin (v) Cytology: neutrophils, macrophages, and bacteria Skin scrapings: ectoparasites Blood culture: bacteria Culture: bacteria recognition and identification Skin biopsy: to confirm folliculitis, perifolliculitis, or furunculosis SECTION THREE: DIAGNOSTIC SKILLS Bathe 2–3 times weekly for 2–3 weeks. Prevent self-trauma. Provide a high-quality diet. Supplement with essential fatty acids. ENDOCRINOLOGY AND REPRODUCTION Table 6.14 / Endocrinology and Reproduction: Abortion and Diabetes Insipidus Abortion Diabetes Insipidus Definition An abortion is the termination of a pregnancy. It may be the result of difficulties with the mother, fetus, or placenta. Exposures to toxins or infections in the dam are well documented. Diabetes insipidus is a disorder of water metabolism due to a deficiency of antidiuretic hormone (ADH) caused by either a lack of release of ADH or renal tubular insensitivity to ADH. Presenting Clinical Signs • Anorexia, depression, lethargy, vomiting, and diarrhea • Early gestation: vaginal discharge, fetid and purulent • Late gestation: restlessness and abdominal contractions • Blindness, disorientation, incontinence, nocturia, PU/PD, seizures, weight loss Examination Findings • Disappearance of previously documented (e.g., palpation, ultrasound, radiogragh) fetuses • Dehydration General • History/clinical signs • Observe for any systemic signs of illness • Clinical signs Laboratory • Bacterial culture: bacteria isolation and identification • RAST or AGID: Brucella canis • Chemistry panel: ↑ sodium • Urinalysis: ↑ protein (v), ↓ specific gravity: <1.010 • Abrupt or gradual water deprivation test: UA specific gravity of <1.025 μg/dL • ADH response test: failure to concentrate urine after exogenous ADH administration Imaging • Radiographs, abdominal: retained fetuses • Ultrasound: uterine pathology and retained fetuses • Nuclear imaging and CT: identify pituitary or hypothalamic lesion Procedures • Necropsy of dead fetuses General • Symptomatic • Fluid therapy • Surgery: cesarean section • Symptomatic Medication • Antibiotics: variable • Prostaglandin • ADH supplement: vasopressin, pitressin tannate Nursing Care • Postparturition or postoperative nursing care • Free access to water Patient Care • Physical examination 7–14 after treatment • Free access to water • Sodium-restricted diet Prevention/ Avoidance • OVH • Avoid circumstances that might markedly increase water loss Follow-Up Treatment Diagnosis Presentation Disease 6 CHAPTER 6 / GENERAL MEDICINE 227 Table 6.14 / Endocrinology and Reproduction: Abortion and Diabetes Insipidus (Continued) Abortion Diabetes Insipidus Complications • • • • • • • • Primary disease Prognosis • Excellent if treated early • Very good prognosis with lack of release of ADH • Guarded prognosis with renal insensitivity to ADH • In the first trimester, it is very difficult to distinguish between abortion and infertility. • Aborted fetuses or placenta may be infectious; isolate animal from all other dogs, pups, and humans. • Water deprivation test is contraindicated in dehydrated animals. Follow-Up Disease Notes 6 Death Infertility Peritonitis Pyometra Sepsis Shock Uterine rupture Table 6.15 / Endocrinology and Reproduction: Diabetes Mellitus Diabetes Mellitus Definition A chronic disorder of carbohydrate metabolism, characterized by hyperglycemia and glucosuria and resulting from inadequate production or utilization of insulin Type 1: insulin-dependent (low to absent secretory ability) Type 2: non–insulin-dependent (inadequate or delayed insulin secretion or peripheral tissue insensitivity to insulin) Diagnosis Presentation Disease 228 Presenting Clinical Signs • PU/PD, polyphagia, and weight loss • Later stages: anorexia, lethargy, oily hair coat, dorsal muscle wasting, depression, and vomiting Examination Findings • Hepatomegaly, cataracts (canine), plantigrade stance (feline) General • History/clinical signs Laboratory • CBC: eosinophilia and lymphocytosis (v), ↑ PCV/TP, mild nonregenerative anemia, Heinz bodies • Chemistry panel: ↑ glucose (>200 mg/dL in dogs: >250 mg/dL in cats), cholesterol, sodium, phosphate, alk phos, ALT, AST, and ↓ potassium and metabolic acidosis Imaging • Radiographs, thoracic: microcardia and hypoperfusion of lungs • Ultrasound: pancreatic and liver pathology Procedures • Liver biopsy (e.g., jaundiced patients) SECTION THREE: DIAGNOSTIC SKILLS Table 6.15 / Endocrinology and Reproduction: Diabetes Mellitus (Continued) Follow-Up Treatment Disease Diabetes Mellitus General • Supportive • Fluid therapy Medication • Insulin: PZI, NPH, glargine, Vetsulin, caninsulin • Oral hypoglycemics: glipizide, metformin, troglitazone, acarbose Nursing Care • Free access to water • Try to mimic the same feeding schedule used at home. • Low stress environment Patient Care • • • • Maintain a regimented feeding and medication schedule. Monitor for signs of iatrogenic hypoglycemia, PU/PD, appetite, and body weight. Provide consistent amount of exercise every day to prevent fluctuations in insulin requirements. Monitor serial BGs (initially every few weeks and then once regulated, every few months) or monitor serum fructosamine or glycosylated hemoglobin. Prevention/Avoidance • Prevent or correct obesity. • Avoid unnecessary use of corticosteroids or megesterol acetate. Complications • • • • • Prognosis • Cats may recover but may relapse later. • Dogs have permanent disease. • Normal life span is expected with treatment. Notes 6 Secondary infections Anemia and hemoglobinemia with severe hypophosphatemia Cataracts (canine) Diabetic neuropathy (feline) Seizures or coma • Meals should coincide with the administration of insulin. • Feed a canned low-carbohydrate and high-protein diet twice daily (esp. feline). • Patients scheduled for surgery: NPO after 12 AM, give 1/2 the normal dose of insulin the morning of surgery, monitor blood glucose levels, and administer R insulin if needed following the surgery maintain the patient on a 5% dextrose IV drip until food intake has resumed. • Keeshond, Puli, Miniature Pinscher, and Cairn Terrier Note: See Insulin Therapy, Skill Boxes 8.14, 8.15, and 8.16, page 357. CHAPTER 6 / GENERAL MEDICINE 229 Table 6.16 / Endocrinology and Reproduction: Dystocia and Eclampsia Dystociaa Eclampsia (Puerperal tetany) Definition Dystocia results from abnormalities associated with parturition. They are due to either primary or secondary uterine inertia. Primary uterine inertia is the failure of uterine contractions sufficient to deliver. Secondary uterine inertia is fetal obstruction due to large pups, narrow birth canal, abnormal pup position, etc. Eclampsia can be a life-threatening condition often seen 1–4 weeks postpartum. It is due to extremely low serum ionized calcium levels. Clinical Signs • Abnormal vaginal discharge, active straining for >45 minutes, crying and biting at vulvar area, intermittent weak contractions for >2 hours, presence of fetal membrane in the vulva for >15 minutes, resting phase for >4–6 hours without straining • Ataxia, convulsions, drooling, muscle tremors, nervousness, pacing, panting, restlessness, salivation, seizures, stiff gait, tachypnea, tremors, whining Examination Findings • Vaginal stenosis • Dilated pupils, ↓ pupillary light response, pyrexia, tachycardia, tetany General • History/clinical signs • Prolonged gestation: >72 days from the first mating • History/clinical signs Laboratory • CBC: ↑ PCV/TP and ↓ glucose and calcium • Chemistry panel: ↓ calcium (≤7 mg/dL) and glucose (rare) Imaging • Radiographs, abdominal: fetal death characterized by intrafetal gas patterns, collapsed spinal cord, overlapping of the skull bones or pup in the birth canal • Ultrasound: uterine pathology and fetal distress (↓ heart rate and fetal bowel movements) • N/A Procedures • Vaginal examination • ECG: prolonged QT interval, bradycardia, tachycardia or VPCs General • • • • • Symptomatic Medication • Anesthesia: isoflurane or reversible induction agents • Ecbolic agents: oxytocin, calcium gluconate, ergonovine maleate or dextrose • Tranquilizer: acepromazine • Calcium supplementation: calcium gluconate • Tranquilizers: diazepam Nursing Care • Postparturition or standard postoperative • Calcium administration often leads to vomiting, which will subside. • Cold water baths and enemas • Hand-raise puppies until crisis is over. Patient Care • Postparturition care • Monitor growth and nursing habits of the neonates. • Monitor calcium levels • Supplement oral calcium throughout lactation Prevention/ Avoidance • OVH • Scheduled cesarean section • Do not supplement with calcium during gestation. • OVH Presentation Disease Follow-Up Treatment Diagnosis 6 230 Symptomatic Fluid therapy Manual manipulation via vagina Surgery: emergency cesarean section SECTION THREE: DIAGNOSTIC SKILLS Table 6.16 / Endocrinology and Reproduction: Dystocia and Eclampsia (Continued) Dystociaa Eclampsia (Puerperal tetany) Complications • Maternal or fetal death • ↑ risk in future pregnancies • Neonate stuck in birth canal • Cerebral edema • Death Prognosis • Excellent if discovered early • Good with immediate treatment • Poor with delayed treatment • Rule out obstructive dystocia before administering ecbolics agents. • Welsh Corgi and brachycephalic breeds tend to have a congenitally small pelvis, and the pups tend to have large heads and shoulders. • Response to treatment is rapid; therefore, treat if the diagnosis is suspected while lab confirmation is pending. • Probable reoccurrence with subsequent litters Follow-Up Disease Notes See Table 2.4, Normal Parturition of Canines and Felines and Skill Box 7.4 Neonatal Resuscitation Post-Cesarean, page 317. 6 Table 6.17 / Endocrinology and Reproduction: Hyperadrenocorticism and Hyperparathyroidism Hyperadrenocorticism (HAC, Canine Cushing’s Syndrome) Hyperparathyroidism Definition Hyperadrenocorticism is most commonly found in canines middle to old age. It is caused by the excessive secretion of cortisol by the adrenal glands. The excess glucocorticoid comes from (1) excessive secretion of ACTH from a pituitary microadenoma or (2) an adrenocortical tumor. Excessive administration of corticosteroids can also result in iatrogenic HAC, a separate syndrome. The disease results from excessive secretion of the parathyroid hormone (PTH). This can be caused by an adenoma, carcinoma, or hyperplasia of the parathyroid gland. Clinical Signs • Behavior changes, bilaterally symmetric alopecia, circling, dull haircoat, dyspnea, excessive panting, infertility, pendulous, distended or pot-bellied abdomen, polyphagia, PU/PD, recurrent skin infections, seizures • Anorexia, ataxia, constipation, depression, facial swelling, lethargy, muscle tremors, PU/PD, seizures, shivering, stiff gait, twitching, vomiting, weakness Examination Findings • Muscle and testicular atrophy, thin skin with hyperpigmentation and ↑ fragility (esp. feline) • Cataracts, tachycardia General • History: exogenous glucocorticoid use • Clinical signs • Clinical signs • Palpation of a parathyroid gland (feline) Laboratory • CBC: steroid leukogram and mild erythrocytosis (v) • Chemistry panel: ↑ alk phos, cholesterol, ALT and glucose (v) • Urinalysis: ↑ protein, blood, bacteria, WBCs, cortisol-to-creatinine ratio (>35), and ↓ specific gravity: <1.020 • ACTH stimulation test: to diagnose type, >20 μg/dL with endogenous HAC, blunted or no response iatrogenic HAC • Low dose dexamethasone suppression test: to confirm diagnosis, >1 μg/dL during 8 hour test • High dose dexamethasone suppression test: to differentiate type, <1.5 μg/dL with pituitary dependent HAC and >1.5 μg/dL with adrenocortical neoplasia • Endogenous plasma ACTH concentration: to differentiate type, >40 pg/mL with pituitary dependent HAC and <20 pg/mL with adrenocortical tumors • • • • Presentation Disease Diagnosis a Chemistry panel: ↑ calcium, ALT, alk phos, ↓ phosphorus Urinalysis: ↓ specific gravity Serum ionized calcium: ↑ values Serum PTH concentration: ↑ values CHAPTER 6 / GENERAL MEDICINE 231 Table 6.17 / Endocrinology and Reproduction: Hyperadrenocorticism and Hyperparathyroidism (Continued) Hyperadrenocorticism (HAC, Canine Cushing’s Syndrome) Hyperparathyroidism Imaging • • • • • Radiographs, skeletal: generalized osteopenia, ↑ bone resorption (alveolar bone of the jaw) and cyst-like areas in the bone • Ultrasound: visualization of the parathyroid gland, urolithiasis, and renal abnormalities Procedures • N/A • ECG: premature ventricular complexes General • Symptomatic • Radiation therapy: pituitary macroadenoma or marcocarcinoma • Surgery: removal of adrenal tumor, removal of pituitary (hypophysectomy) • Symptomatic • Fluid therapy • Surgery: removal of the parathyroid gland adenoma Medication • • • • • Diuretics: furosemide • Calcitriol (postoperative for transient iatrogenic hypocalcemia) Nursing Care • Treated as outpatient • Standard postoperative Patient Care • Monitor for reoccurrence of previous clinical signs • Perform an ACTH response test 5–10 days initiation of medication (except L-deprenyl) then every 3–6 months • Monitor for inappetance, severe decreased water consumption, attitude, activity, vomiting, or diarrhea relating to the medication • Monitor serum calcium 1–2 times daily for 1 week postoperative • Diet of ↑ phosphorus and ↓ calcium Prevention/ Avoidance • N/A • N/A Complications • • • • • • • • Hypocalcemia (iatrogenic) • Renal failure Prognosis • Guarded due to the number of complications associated with this disease • Excellent with proper treatment • Poor with associated renal disease • Easy cutaneous bruising (canine), venipuncture should be perform with extra care • Most commonly seen in Poodle, Dachshund, Boston Terrier, and Boxer • This is the only condition that causes ↓ phosphorous and ↑ calcium, • Keeshond, German Shepard, Norwegian Elkhound, and Siamese cat Follow-Up 6 Treatment Diagnosis Disease Notes 232 Radiographs, thoracic: mineralization of bronchial walls Radiographs, abdominal: adrenal tumors and hepatomegaly Ultrasound: ↑ liver and adrenal glands CT: visualization of pituitary tumors and possibly pituitary microadenomas (radiographs and ultrasounds can be used, but are not as accurate) Corticosteroids: prednisone or prednisolone Ketoconazole L-Deprenyl Mitotane, trilostane Thromboembolism Congestive heart failure Hypertension Recurrence of clinical signs Progression of CNS signs Infection: skin and urinary Diabetes mellitus SECTION THREE: DIAGNOSTIC SKILLS Table 6.18 / Endocrinology and Reproduction: Hyperthyroidism and Hypoadrenocorticism Hyperthyroidism (Feline) Hypoadrenocorticism (Addison’s Disease) Definition A multisystemic metabolic disorder most commonly seen in middleaged to old felines. It is caused by an excessive amount of circulating thyroid hormone. The disease causes an increased basal metabolic rate, which in turn causes the disease’s clinical signs. Hypoadrenocorticism is a disease of the adrenal gland resulting in a deficiency of glucocorticoid and/or mineralcorticoid secretion from the adrenal cortex. The cause is often thought to be idiopathic or sometimes due to infection, hemorrhagic infarctions, metastatic neoplasia, trauma, and amyloidosis. Mostly seen in young to middleaged female dogs. Clinical Signs • ↑ Appetite, behavioral changes, diarrhea, dyspnea, excessive shedding and matting, heat intolerance, hyperexcitability, hyperventilation, panting, PU/PD, restlessness, tachypnea, unkept haircoat, vomiting, weakness, weight loss • Intermittent anorexia, collapse, depression, diarrhea, lethargy, melena, muscle weakness, polyuria, PU/PD, shivering, vomiting, weight loss Examination Findings • Arrhythmia, enlargement of 1 or both thyroid glands, gallop, lymphadenopathy, pallor, systolic murmur, tachycardia • Arrhythmias, dehydration, progressing to bradycardia, shock, weak pulses General • History/clinical signs • Palpation of thyroid gland(s) • History/clinical signs Laboratory • CBC: erythrocytosis (v), mature leukocytosis, eosinopenia, monocytosis, ↑ PCV, MCV, Heinz bodies (v) • Chemistry panel: ↑ ALT, AST, alk phos, BUN, creatinine, calcium, glucose, phosphorus, bilirubin, lactate • Basal serum thyroid hormone concentration: >4 μg/dL • Free T4 by equilibrium analysis: ↑ value • T3 suppression test: >1.5 μg/dL • TRH response test: little to no ↑ in serum T4 • TLI: ↓ TSH • CBC: normocytic, normochromic nonregenerative anemia • Chemistry panel: ↑ ALT, AST, calcium, potassium, creatinine, BUN and ↓ phosphorus, sodium, chloride, cholesterol, glucose • Urinalysis: ↑ ketones, glucose, ↓ specific gravity: <1.030 • ACTH stimulation test, primary hypoadrenocorticism is <1 μg/dL • Plasma concentration of ACTH: primary is >500 pg/mL and secondary is <20 pg/mL • Plasma aldosterone: ↓ value • Sodium : potassium ratio: <27 : 1 Imaging • Radiographs, thoracic: cardiomegaly, pulmonary edema, valentineshaped heart • Ultrasound, abdominal: underlying renal disease • Echocardiography: atrial and LV dilation, hypercontractility • Thyroid pertechnetate scan: + thyroid radioisotope • Radiographs, abdominal: cystic or renal calculi, cholecystitis, and pancreatitis Procedures • ECG: atrial fibrillation, APCs, VPCs, tachycardia • Blood pressure: hypertension • ECG: peaking of T waves, prolonged P-R waves until P wave ultimately disappears, QRS complex widens, and R-R intervals become irregular Diagnosis Presentation Disease CHAPTER 6 / GENERAL MEDICINE 233 6 Table 6.18 / Endocrinology and Reproduction: Hyperthyroidism and Hypoadrenocorticism (Continued) Treatment Disease Follow-Up 6 Hyperthyroidism (Feline) Hypoadrenocorticism (Addison’s Disease) General • Symptomatic • Radioiodine therapy • Surgery: thyroidectomy • Supportive • Fluid therapy (acute cases) Medication • β-Adrenergic blocking drugs • Antiarrythmics: propranolol • Antithyroid: methimazole, carbimazole, ipodate • Corticosteroids: prednisolone sodium succinate, dexamethasone, prednisone • Mineralcorticoids: DOCP, fludrocortisones, hydrocortisone hemisuccinate, hydrocortisone phosphate • Calcium gluconate • Sodium bicarbonate Nursing Care • Treated as outpatient • Treated as outpatient Patient Care • Monitor CBC, BUN, creatinine, and serum T4 every 2–4 weeks during first 3 months of methimazole treatment. • Monitor serum T4 the first week and then every 3–6 months after thyroidectomy. • Monitor T4 the second week and then every 3–6 months after radioiodine therapy. • Monitor electrolytes weekly until stabilized. • Monitor electrolytes, BUN and creatinine monthly for 3 months, then every 3–12 months. Prevention/ Avoidance • N/A • N/A Complications • • • • • • • PU/PD from medication Prognosis • Excellent with treatment • Poor with thyroid carcinoma • Good to excellent with proper diagnosis and treatment • Poor prognosis with tumors causing the disease • Clinical signs are expected to completely resolve with proper treatment. • Radioiodine therapy is the best choice of treatment to cure the disease. • Renal disease may become apparent once euthyroidism is established. • Most commonly seen in female dogs <7 years old. • Glucocorticoids (e.g., prednisolone) need to be ↑ during times of stress such as travel, hospitalization, and surgery. • Great Dane, Rottweiler, Portuguese Water Spaniel, West Highland White Terrier, Wheaten Terrier, and Standard Poodle Notes 234 Congestive heart failure Dehydration Diarrhea Hypothyroidism (iatrogenic) Renal damage Retinal detachment SECTION THREE: DIAGNOSTIC SKILLS Table 6.19 / Endocrinology and Reproduction: Hypoparathyroidism, Hypothyroidism, and Mastitis Hypoparathyroidism Hypothyroidism (Canine) Mastitis Definition Hypoparathyroidism is a deficiency in the secretion of the parathyroid hormone. This condition is most commonly seen in dogs as naturally occurring and typically following thyroidectomy in cats. Hypothyroidism is the most commonly diagnosed endocrine disease in the dog. A condition that results from inadequate production and release of T4. Caused by either destruction of the thyroid gland or impaired secretion of TSH by the pituitary gland. Mastitis is a bacterial infection of one or more of the lactating glands. Seen in the postpartum dam and queen. Clinical Signs • Anorexia, ataxia, depression, diarrhea, listlessness, muscle spasms, nervousness, panting, rigid limb extension, seizures, stiff gait, tremors, twitching, vomiting, weight loss • Abortion, anestrus, cold intolerance, exercise intolerance, infertility, lethargy, mental dullness, muscle weakness, weight gain • Anorexia, cachexia, depression, lethargy, mammary gland abscess • Neglected, bloated, crying, restless, failure to thrive neonates Examination Findings • Cataracts, tachycardia, weak pulses • Bradycardia, hyperpigmentation, impaired myocardial contractility, myxedema, neuropathies, pyodermas, testicular atrophy • Bilaterally symmetrical nonpruritic alopecia on ventral and lateral trunk, caudal thighs, dorsal tail, dorsal nose and ventral neck • Dehydration, pyrexia • Mammary gland(s): firm, swollen, warm, painful, purulent or hemorrhagic discharge General • Clinical signs • Clinical signs • History/clinical signs Laboratory • Chemistry panel: ↑ phosphorus and ↓ calcium • Serum PTH concentration: ↓ value • CBC: mild normocytic, normochromic, nonregenerative anemia • Chemistry panel: ↑ cholesterol, ALT, AST, SAP, CK, ↓ calcium • Basal serum T4 levels: <1.0 μg/dL • Serum TSH concentration: ↑ value • Free T4 by equilibrium analysis: ↓ value • CBC: leukocytosis with left shift or leukopenia with sepsis and ↑ PCV (v) • Chemistry panel: ↑ TP and BUN • Cytology and culture, milk: neutrophils, macrophages, RBCs, bacteria isolation and identification Imaging • N/A • N/A • N/A Procedures • ECG: prolongation of QT and ST segments, deep wide T waves, and tachyarrhythmias • N/A • N/A General • Supportive • Fluid therapy • Symptomatic • Supportive • Fluid therapy • Surgery: lance, debride, drain placement of infected glands Medication • Calcium supplementation: calcium gluconate, calcium lactate, calcium carbonate • Vitamin D supplementation: vitamin D, hytakerol, calcitriol • Sodium levothyroxine • Antibiotics: variable, based on milk pH Treatment Diagnosis Presentation Disease CHAPTER 6 / GENERAL MEDICINE 235 6 Table 6.19 / Endocrinology and Reproduction: Hypoparathyroidism, Hypothyroidism, and Mastitis (Continued) 6 Follow-Up Treatment Disease Hypoparathyroidism Hypothyroidism (Canine) Mastitis Nursing Care • Treated as outpatient • Treated as outpatient • Hand raise puppies or find a surrogate dam if glands are necrotic and need surgical care. • Alternate cold and warm compress and manually milk glands several times a day Patient Care • Check serum calcium weekly for 1 month, monthly for 6 months, then every 2–4 months. • Diet of ↑ calcium and ↓ phosphorus • Check serum T4 levels after 1 month of therapy, then every 6–12 months. • Same as above • Monitor the growth and feeding habits of the neonates. Prevention/ Avoidance • N/A • N/A • Clean environment • Clip toenails of neonates. • Shave hair around mammary glands. Complications • Hypercalcemia (iatrogenic) • Renal disease • Thyrotoxicosis from administration of high does of L-thyroxine • Abscessed gland • Hand-raising of neonates Prognosis • Excellent with close monitoring of calcium levels • Excellent with proper treatment • Poor if disease is due to a tumor of the thyroid gland • Good with prompt treatment • Check albumin level as it is the most common cause for pseudo-hypocalcemia. • Felines with transient hypoparathyroidism postthyroidectomy typically regain normal function by 4–6 months • Toy Poodle, Miniature Schnauzer, German Shepard, Labrador Retreiver, and Scottish Terrier • Failure of clinical signs to significantly improve within 3 months may be due to an incorrect diagnosis • Improvement should be seen within 1–2 weeks after initiating treatment (e.g., mostly behavior and appetite). • Serum T4 levels should be checked 4–6 hours post administration of L-thyroxine. • Treatment is lifelong. • Golden Retriever, Doberman Pinscher, Irish Setter, Great Dane, Airedale Terrier, Old English Sheepdog, Miniature Schnauzer, Cocker Spaniel, Poodle, and Boxer • Avoid antibiotics that may be passed in the milk and cause deleterious effects to the neonates. Notes 236 SECTION THREE: DIAGNOSTIC SKILLS Table 6.20 / Endocrinology and Reproduction: Pregnancy and Pyometra Disease Pyometra may be seen in both dogs and cats following estrus or progesterone administration by 1–2 months. It is caused by a hormonal change in the uterus that allows for secondary infections and is seen with either an open cervix or closed cervix. Clinical Signs • Enlarged abdomen, mammary gland development and lactation, nesting instinct • Anorexia, depression, lethargy, depression, diarrhea, vomiting • Open-cervix pyometra: mild systemic signs, PU/PD, vaginal discharge (purulent, blood, mucus) • Closed-cervix pyometra: collapse, more severe systemic signs Examination Findings • Documented fetuses (e.g., palpation, ultrasonography, radiogragh) • Abdominal distention, enlarged uterus, hypothermia, septicemia, shock General • History/clinical signs • Abdominal palpation: 25–36 days after breeding (dogs) and 21–28 days after breeding (cats) • History/clinical signs Laboratory • Chemistry panel: ↑ relaxin and progesterone levels • CBC: neutrophilia with a left shift and mild nonregenerative anemia • Chemistry panel: ↑ globulin, protein, ALT, ALP, azotemia (v) and electrolyte imbalances • Urinalysis: ↑ protein and isothenuric • Cytology and culture: bacteria isolation and identification Imaging • Radiographs, abdominal: fetal skeletal calcification ≥42 days of gestation • Radiographs, abdominal: enlarged or ruptured uterus and peritonitis • Ultrasonography: differentiate pyometra from pregnancy, intraluminal uterine contents, uterine wall thickened Procedures • Ultrasound: 16 days of gestation • Vaginoscopy: determine site of origin of purulent discharge General • N/A • • • • Medication • N/A • Antibiotics: cephalothin, ampicillin or enrofloxacin • Prostaglandin F2α (PGF2α) Nursing Care • N/A • Standard postoperative Diagnosis Treatment Pyometra Pregnancy is the condition of carrying a developing embryo(s) in the uterus. Parturition consists of 3 stages. Stage 1 is characterized by restlessness, anxiety, nesting behavior, and shivering and can last 6– 12 hours. Stage 2 is the actual delivery of the fetus. There are visible contractions and the first fetus should be delivered within 1–2 hours from the onset of stage 2. There may be a resting period for up to 4 hours after the delivery of a fetus. Stage 3 is the expulsion of the placenta typically following the deliver of each fetus. Definition Presentation Pregnancy Symptomatic Fluid therapy OVH with abdominal lavage Medical management CHAPTER 6 / GENERAL MEDICINE 237 6 Table 6.20 / Endocrinology and Reproduction: Pregnancy and Pyometra (Continued) Follow-Up Disease 6 Pregnancy Pyometra Patient Care • Provide adequate nutrition throughout pregnancy. • Provide a quiet safe place for the dam/queen to deliver. • Monitor parturition to become aware of any complications. • Reexam medical managed pyometra cases 1 week after initiation of treatment. • Monitor progesterone levels 1 week after discontinuing treatment. • Vaginal discharge may be seen for 4 weeks post treatment. Prevention/ Avoidance • OVH • Supervision • OVH Complications • • • • • • • • • Prognosis • Excellent with proper prenatal care • Good with OVH and no abdominal contamination • Guarded with medical management of closed pyometra • The length of gestation is 63 days from ovulation but may extend from 56 to 72 days. • A transient temperature drop occurs within 24 hours of the onset of parturition. • A normal fetal heart rate is twice that of the mother. • Do not perform cystocentesis when pyometra is suspected due to friable uterus and possible contamination of abdomen. • Diluting PGE2α with 1 : 1 sterile saline and walking an animal for 30 minutes after giving the injection may ↓ side effects. Notes Dystocia Retained fetuses or placenta Eclampsia Mastitis Estrus sooner after treatment PGF2α side effects Recurrent pyometra with medical management necessary Sepsis and peritonitis Uterine rupture GASTROENTEROLOGY Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis Anal Sac Disease Cholangitis and Cholangiohepatitis Definition This is the most common disease of the anal area in small animals, especially dogs. It is the impaction, inflammation, infection, abscess, and/or rupture of the anal gland(s). Cholangitis is inflammation confined to the bile ducts. Cholangiohepatitis is the inflammation of the bile ducts and adjacent hepatocytes. The inflammatory infiltrates are either supprative (S), most commonly seen in younger cats, or nonsuppurative (NS), mostly seen in older cats. Clinical Signs • Behavior change, biting, chewing, discomfort in sitting, licking, malodorous, painful defecation, rubbing at perianal area, scooting, tail chasing, tenesmus • Anorexia, depression, diarrhea, lethargy, vomiting, weight loss Examination Findings • Perianal discharge, swollen anal glands • Abdominal pain, ascites, dehydration, generalized lymphadenopathy (rare), hepatomegaly (v), pyrexia, jaundice Presentation Disease 238 SECTION THREE: DIAGNOSTIC SKILLS Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis (Continued) Anal Sac Disease Cholangitis and Cholangiohepatitis General • Clinical signs • Palpation of the anal glands • History/clinical signs Laboratory • Cytology, exudate/secretion: WBCs and bacteria • Culture: bacteria isolation and identification • CBC: mild nonregenerative anemia and neutrophilia with a left shift • Chemistry panel: ↑ bilirubin, ammonia, ALT, AST, ALP, GGT, globulin, ↓ albumin and BUN • Urinalysis: ↓ bilirubin • Bile acid concentrations: ↑ values • Coagulation profile: prolonged • Biopsy: • S: ↑ neutrophils, intrahepatic • NS: lymphocytic portal infiltrates • Culture, bile: bacteria isolation and identification Follow-Up Treatment Diagnosis Disease 6 Imaging • N/A Procedures • N/A General • Expression of glands • Duct cannulation and irrigation • Surgery: anal sacculectomy • Supportive • Fluid therapy • Laparotomy to relieve obstruction Medication • Antibiotics (systemic): chloramphenicol, penicillin, or aminoglycosides • Antibiotics (topical): panalog • • • • Nursing Care • Treated as outpatient • Standard postoperative if surgery • Nutritional support • Vitamin supplementation: vitamin E and water-soluble vitamins Patient Care • • • • • Check liver enzymes and bilirubin every 7–14 days initially, then quarterly. Prevention/ Avoidance • High-fiber diet • Routine expression • Control inflammatory bowel disease. Complications • Fecal incontinence following anal sacculectomy • Rupture • Septicemia • • • • • Prognosis • Excellent • Guarded to poor with fecal incontinence • Good with early treatment of suppurative disease • Variable with nonsuppurative High fiber diet Exercise Express anal glands every 3–14 days until material is normal. Weight control • Radiographs, abdominal: hepatomegaly and cholelithiasis • Ultrasonography: cholelithiasis, cholecystitis, obstruction, pancreatic abnormalities, and ↑ echogenecity of the liver Antibiotics: ampicillin, amoxicillin cephalosporins, metronidazole Corticosteroids (NS): prednisolone Ursodeoxycholic acid: actigal Vitamin K1 therapy Death Diabetes mellitus Hepatic lipidosis Pancreatitis and triad disease Recurrence of nonsuppurative forms CHAPTER 6 / GENERAL MEDICINE 239 Table 6.21 / Gastroenterology: Anal Sac Disease, Cholangitis, and Cholangiohepatitis (Continued) Disease Anal Sac Disease Cholangitis and Cholangiohepatitis Notes • Color and consistency of anal gland contents: • Clear or pale yellow-brown: normal • Thick, pasty brown: impaction • Creamy yellow or thin green: infection • Yellow: inflammation • Red-brown exudate: abscessed • Caution: Drugs used must be selected with care to not further damage the liver through metabolism. • Caution: Corticosteroids should not be used in suppurative forms. • Himalayan, Persian, and Siamese cats 6 Table 6.22 / Gastroenterology: Constipation and Megacolon Constipation and Megacolon Definition Constipation is a condition of prolonged fecal transit time, which contributes to increased water absorption leaving a hard, dry fecal mass. These fecal masses can cause irritation and inflammation of the intestinal mucosa and disrupt normal motility. Treatment Diagnosis Presentation Disease 240 Clinical Signs • Anorexia, blood, depression, mucus, tenesmus, hard, dry feces, lack of fecal output, unkept haircoat, vomiting, weakness Examination Findings • Dehydration, distended and painful abdomen General • History/clinical signs • Abdominal palpation: enlarged colon with large fecal mass and a colon full of hypersegmented fecal balls • Digital rectal examination: fecal impaction and possible detection of underlying condition Laboratory • CBC: stress leukogram and ↑ PCV/TP • Chemistry panel: ↑ calcium, ↓ chloride and potassium • T4 (feline): ↑ values Imaging • Radiographs, abdominal: enlarged colon with large fecal mass, colon full of hypersegmented fecal balls, possible detection of underlying condition (e.g., pelvic fracture, spinal cord abnormalities) • Contrast, barium enema contrast • Ultrasound: obstructive tumors Procedures • Colonoscopy: obstructive mass or lesions General • • • • Supportive Fluid therapy Manual evacuation of the colon Surgery: colostomy, colectomy, pelvic osteotomy SECTION THREE: DIAGNOSTIC SKILLS Table 6.22 / Gastroenterology: Constipation and Megacolon (Continued) Disease Medication • Acetylcholinesterase inhibitors: ranitidine, nizatidine, neostigmine • Laxatives: • Bulk-forming: psyllium, pumpkin • Emollient: Colace, DSS • Lubricant: mineral oil, Laxatone, or sterile lubricant jelly • Osmotic: lactulose, milk, or glycerin • Misoprostol • Prokinetic agents: cisapride Nursing Care • Encourage to defecate: clean litter pan, multiple walks Patient Care • Encourage activity and exercise after postoperative recovery. • Dietary fiber supplements: psyllium, wheat bran, pumpkin • ↑ Exercise Treatment Follow-Up Constipation and Megacolon Prevention/ Avoidance • Same as above Complications • • • • Prognosis • Fair with lifelong treatment • Poor with megacolon Notes 6 Megacolon Obstipation Perforation of colon wall during manual evacuation Peritonitis, diarrhea, or stricture formation post surgery • Typically seen in the transverse and descending colon • Verify adequate hydration before adding dietary fiber supplements Table 6.23 / Gastroenterology: Diarrhea Disease Diarrhea Acute Presentation Definition Chronic Diarrhea can be acute or chronic (lasting longer than 3–4 weeks) and either small bowel or large bowel. The causes range from dietary indiscretion, toxins, drugs, intestinal parasites, infectious diseases, and systemic or metabolic disturbances. Clinical Signs • • • • Anorexia, lethargy, vomiting Clinical signs of an underlying condition Small bowel diarrhea: watery, voluminous, and fetid Large bowel diarrhea: watery, mucoid, bloody feces with tenesmus and ↑ sense of urgency Examination Findings • Abdominal pain, dehydration, ileus, pyrexia CHAPTER 6 / GENERAL MEDICINE 241 Table 6.23 / Gastroenterology: Diarrhea (Continued) Disease Diarrhea Acute General • History/clinical signs • Abdominal palpation: mass lesions, pain, mesenteric lymphadenopathy, thickened or fluid-distended bowel loops • Digital rectal palpation: masses, strictures, or anal diseases Laboratory • • • • • • Fecal flotation: parasites or bacteria Fecal direct smear: cysts, larvae, and trophozoites Cytology, fecal: bacteria, fungi, protozoan, inflammatory cells Culture, fecal: + T. foetus (feline) ELISA: parvovirus, Giardia, rotavirus Folate and cobalamin: dependent on different conditions and locations of problems • IFA Giardia/Crypotospordium: + • • • • Imaging • Radiographs, abdominal: foreign bodies, obstruction, intussusception, and ileus • Radiographs, abdominal: obstruction, mass, foreign body, organomegaly • Contrast study: bowel wall thickening or irregularity, tumor, stricture or foreign body • Ultrasonography: bowel wall thickening or irregularity, mass, foreign body, intussusception, ileus, or other disease process Procedures • ± Endoscopy: obtain biopsies • Endoscopy: obtain biopsies General • Supportive • Fluid therapy • Surgery: laparotomy to remove obstruction • Supportive • Fluid therapy • Surgery: laparotomy to remove obstruction or mass or obtain full thickness biopsy Medication • • • • • • Anthelmintics: fenbendazole and metronidazole Nursing Care • NPO for at least 24 hours • Provide a clean litter box or frequent walks. • Provide a clean litter box or frequent walks. Patient Care • Recheck fecal analysis following treatment for parasites. • Small, frequent meals • Bland or hypoallergenic diet • Bland or hypoallergenic diet • Monitor fecal output: consistency, frequency • Monitor body weight Prevention/ Avoidance • Yearly fecal analysis • Yearly fecal analysis Diagnosis Treatment Follow-Up 6 242 Chronic Antibiotics Anthelmintics: fendendazole and metronidazole Local protectant: bismuth subsalicylate Motility modifiers: opiates, loperamide, diphenoxylate Probiotics SECTION THREE: DIAGNOSTIC SKILLS CBC: eosinophilia, macrocytosis, and anemia Fecal flotation: parasites or bacteria Fecal cytology: infectious agents or inflammatory cells Folate and cobalamin: ↓↑ depending on different conditions Table 6.23 / Gastroenterology: Diarrhea (Continued) Follow-Up Disease Diarrhea Acute Chronic Complications • Intussusception • Dehydration • Abdominal effusion with intestinal adenocarcinoma • Inflammatory bowel disease Prognosis • Excellent in mild cases and with proper treatment of severe cases • Poor with chronic diarrhea unresponsive to treatment Notes • Most acute diarrhea is self-limiting within 3–4 days. • Do not administer bismuth subsalicylate to cats. 6 Table 6.24 / Gastroenterology: Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus Exocrine Pancreatic Insufficiency (EPI) Gastric Dilatation-Volulusa (GDV, gastric torsion, bloat) Definition EPI is the insufficient secretion of digestive enzymes and clinical signs of malabsorption. It occurs with severe progressive loss of acinar tissue from atrophy and is most commonly seen in middle-aged to older dogs. GDV is the process in which the stomach becomes dilated with gas or fluid and rotates on its central axis. Gastric dilatation can also occur without torsion, but surgery is still indicated as there is an 80% recurrence rate. Clinical Signs • Cachexia, coprophagia, diarrhea, dull haircoat, excessive shedding, feces voluminous, flatulence, greasy oily hair around perineum, ↓ muscle mass, pica, ravenous appetite, unthrifty, vomiting, ↑ water intake • Abdominal distention, belching, collapse, depression, dry heaving (failed attempts to vomit), excessive salivation, respiratory distress, weakness Examination Findings • Borborygmus, dehydration • ↑ Capillary refill time, cool extremities, ↓ femoral pulses, pale mucous membrane, tachycardia, tachypnea, tympanic cranial abdomen General • History/clinical signs • History/clinical signs Laboratory • CBC: mild lymphophenia and eosinophilia • Chemistry panel: ↑ ALT and ↓ cholesterol, lipids, polyunsaturated fatty acids • TLI assay: <5 μg/dL (dogs) and <31 μg/dL (feline) • TLI stimulation test: no response • Fecal elastase: <10 μg/gm • Fecal proteolytic activity: ↓ values • Oral bentiromide digestion test: minimal ↑ PABA • Folate: variable depending on different conditions • Cobalamin: ↓ value • • • • • • Imaging • N/A • Radiographs, abdominal: “double-bubble” with air-filled pylorus Procedures • N/A • Abdominocentesis/cytology: gastric perforation and peritonitis Diagnosis Presentation Disease CBC: variable PCV/TP Chemistry panel: ↓ potassium Urinalysis: ↑ specific gravity Blood gas analysis: metabolic acidosis Coagulation tests, PT, APTT, FDP: ↑ time Plasma lactate: <6 mmol/L ↑ survival rate CHAPTER 6 / GENERAL MEDICINE 243 Table 6.24 / Gastroenterology: Exocrine Pancreatic Insufficiency and Gastric Dilatation-Volvulus (Continued) Exocrine Pancreatic Insufficiency (EPI) Gastric Dilatation-Volulusa (GDV, gastric torsion, bloat) General • Symptomatic • • • • • • Symptomatic Supportive Fluid therapy Oxygen therapy Decompression with orogastric tube/trocarization/gastric lavage Surgery: exploratory celiotomy with gastropexy Medication • • • • • • • • • • Alkalinizer: sodium bicarbonate Antiarrthymics: lidocaine, procainamide Antibiotics: cefazolin, cefoxitin, enrofloxacin, metronidazole Anticoagulant: heparin Corticosteroids: dexamethasone phosphate H2-receptor: famotidine, ranitidine Nursing Care • Divide daily food intake into 2–3 meals. • Diet should be low in fiber and highly digestible. • Multivitamin, especially fat-soluble vitamins, cobalamin, and tocopherol • • • • NPO for 12–24 hours following surgery Fluid therapy Oxygen therapy Monitor: acid-base status, BP, CBC, chemistry panel, CVP, ECG, electrolytes, urine output Patient Care • Monitor weight gain and fecal consistency. • Gradually ↓ enzyme replacement as animal returns to normal. • Gradually return to normal diet. Prevention/ Avoidance • N/A • Feed smaller meals multiple times a day. • Avoid postprandial exercise. Complications • Small bowel bacterial overgrowth • Inadequate response to pancreatic enzyme replacement • Small intestine disease • • • • • Prognosis • Good with dietary and enzyme management • Poor when associated with diabetes mellitus • Guarded to grave • Good, patients recovering 7 days post treatment • German Shepard, Rough-coated Collie • Cobalamin must be given SQ for absorption • Large, deep-chested breeds: Irish Setter, Great Dane, Saint Bernard, Rottweiler, Alaskan Malamute, Labrador Retriever, German Shepards (any breed possible) Treatment Disease Follow-Up 6 Notes a Antibiotics: tetracyclines, metronidazole, tylosin H2-receptor blocker: cimetidine and ranitidine Pancreatic enzyme replacement added to each meal Vitamin supplements: cobalamin, vitamins E, K1 See Emergency Medicine, Chapter 7, page 314, and Surgery, Chapter 15, page 521. 244 SECTION THREE: DIAGNOSTIC SKILLS Arrythmias Aspiration pneumonia DIC Gastric ulceration and peritonitis Reperfusion illness/toxicosis Table 6.25 / Gastroenterology: Hepatic Disease/Failure Hepatic Disease/Failure (Liver Disease) Definition “Hepatic failure” results from the sudden loss of >75% of functioning hepatic mass, and “hepatic disease” is the accumulation of inflammatory cells in the liver over an extended period of time with adequate liver function. Causes include infectious agents, drugs, toxins, immunemediated, traumatic injury, thermal injury, and hypoxia. Clinical Signs • Anorexia, circling, constipation, dementia, depression, diarrhea, disorientation, hematuria, hypersalivation, lethargy, melena, nausea, PU/PD, seizures, vomiting Examination Findings • Abdominal pain, ascites, ataxia, dementia, hemorrhages, hepatomegaly, pyrexia, jaundice, microhepatica, pallor General • History/clinical signs • Abdominal palpation: hepatomegaly and hepatodynia Laboratory • CBC: normocytic, normochromic nonregenerative anemia, thrombocytopenia and ± nucleated RBCs • Chemistry panel: ↑ ALT, AST, ALP, GGT, total bilirubin, globulin, ammonia, BUN (acute), glucose (chronic), cholesterol and ↓ albumin, BUN (chronic), glucose (acute), and cholesterol • Urinalysis: ↑ bilirubin, urobilinogen, ammonia, bilirubin crystals, ammonium biurate crystals, and ↓ specific gravity • Coagulation profile, ACT, PTT, PT: prolonged • Bile acid concentrations: ↑ values • Fasting bile acid concentrations: >30 μmol/L • Postprandial bile acid concentrations: >30 μmol/L • Blood ammonia concentrations: ↑ values • Ammonia tolerance test: ↑ values Imaging • Radiographs, thoracic: metastasis to lung parenchyma • Radiographs, abdominal: ↑ or ↓ in liver size, changes in tissue characteristics and contours • Ultrasonography: masses, abscesses, cysts, obstructions, and lesions Procedures • Biopsy: to determine the nature and severity of hepatic disease General • • • • Symptomatic Supportive Fluid therapy Paracentesis with respiratory distress Medication • • • • • • • • • • • • Antibiotics: penicillin, ampicillin, cephalosporins, metronidazole, and aminoglycosides Antioxidants: vitamins E, C, S-adenosyl-L-methionine, milk thistle Azathioprine (use cautiously) Cholchicine Corticosteroids: prednisolone GI protectants: sulcralfate H2-blocker: ranitidine and cimetidine Lactulose Phenobarbital Ursodeoxycholic acid: actigal Vitamin K therapy Zinc Treatment Diagnosis Presentation Disease CHAPTER 6 / GENERAL MEDICINE 6 245 Table 6.25 / Gastroenterology: Hepatic Disease/Failure (Continued) Hepatic Disease/Failure (Liver Disease) Nursing Care • • • • • Patient Care • Monitor CBC and serum biochemistry frequently depending on severity of presenting condition. • Follow–up biopsies at 6 and 12 months • Dietary modifications (e.g., ↓ copper) Prevention/ Avoidance • Vaccinate against infectious agents. • Screen susceptible breeds. • Avoid hepatotoxic drugs. Complications • • • • • • Prognosis • Dependent on the amount of viable liver mass left after treatment • ↑ Prognosis with determination of underlying cause Notes Moderate activity restriction Nutritional support Monitor body weight, temperature, pulse, respiration, and mental status. Vigilant monitoring for signs of infection Vitamin and mineral supplements Death DIC and bleeding diatheses GI ulceration Liver failure and liver encephalopathy Renal disease or failure Sepsis • Caution: Drugs used must be selected with care to not further damage the liver through metabolism • Caution: Avoid alkalinizing agents (e.g., lactate, sodium bicarbonate) with patients with hepatic encephalopathy • Bedlington Terrier, Doberman Pinscher, Cocker Spaniel, Labrador Retriever, Standard Poodle, Skye Terriers, and West Highland White Terrier Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease Disease Hepatic Lipidosis (Fatty Liver Disease) Inflammatory Bowel Disease (IBD) Definition Hepatic lipidosis is seen almost exclusively in cats. It is the result of >50% of cells in the liver accumulating excessive trigylcerides. This disease will lead to death if left untreated. This occurs when there is difference in the rates of deposition and metabolism of fat. It often occurs with prolonged anorexia. IBD is a group of gastrointestinal diseases that infiltrate the mucosa and submucosa with inflammatory cells. It may involve the stomach, small and large intestines, or a combination. Lymphocyticplasmacytic is the most common type of IBD, found in both dogs and cats. Clinical Signs • Constipation, depression, diarrhea, lethargy, prolonged anorexia, vomiting, weakness, weight loss • Diarrhea, flatulence, hematochezia, intermittent vomiting, listless, mucus, poor haircoat, steatorrhea, tenesmus, vomiting, weight loss Examination Findings • Dehydration, hepatomegaly, jaundice, muscle wasting, pallor • Mesenteric lymphadenopathy, thickened bowel loops Presentation 6 Follow-Up Treatment Disease 246 SECTION THREE: DIAGNOSTIC SKILLS Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease (Continued) Hepatic Lipidosis (Fatty Liver Disease) Inflammatory Bowel Disease (IBD) General • History/clinical signs: obesity • Clinical signs • Canine IBD Analysis Index (CIBDAI) Laboratory • CBC: normocytic, normochromic nonregenerative anemia with poikilocytosis (if prolonged) and neutrohilia and lymphopenia (v) • Chemistry panel: ↑ ALP, ALT, AST, GGT, ammonia, bilirubin, ↓ potassium, phosphorous, albumin, BUN, and azotemia (v) • Urinalysis: ↑ lipids and bilirubin • Coagulation profile, ACT, PTT, PT: prolonged • Bile acid concentrations: ↑ values • CBC: mild, nonregenerative anemia or mild leukocytosis without a left shift (feline) and neutrophilic leukocytosis with a left shift (canine) • Chemistry panel: ↑ T4 (feline), ↓ protein (canine), and albumin (feline) • Fasting serum TLI: to rule out EPI • Cobalamin and folate assays: ↓↑ depending on different conditions • FeLV/FIV: + results Imaging • Radiographs, abdominal: hepatomegaly • Ultrasonography: hepatomegaly and hyperechoic liver • Radiographs, abdominal: survey films to rule out other diseases • Barium contrast study: mucosal abnormalities and thickened bowel loops • Ultrasonography: measure stomach and intestinal wall thickness and rule out other diseases Procedures • Biopsy: hepatocellular vacuoles • Endoscopy: intestinal biopsies General • Supportive • Fluid therapy • Symptomatic • Fluid therapy if vomiting • Surgery: entertomy biopsies Medication • • • • • • 5-Aminosalicyclic drugs: sulfasalazine, olsalazine, and mesalamine • Antibiotics: metronidazole, oxytetracycline, tylosin • Antidiarrheal drugs: loperamide, diphenoxylate • Corticosteroids: prednisone, budesonide • Chemotherapy: chlorambucil • Cyclosporin A • Immunsuppression: azathioprine • Probiotics Nursing Care • Aggressive nutritional support via syringe, nasogastric tube, esophagostomy tube or gastrotomy tube • Vitamin supplementation: vitamin B12, vitamin E, thiamine, taurine, arginine, L-carnitine, and L-citrulline • Nutritional support if severely malnourished • Vitamin supplementation: folic acid, cobalamin, omega-3, vitamin B12, fat-soluble vitamins Patient Care • Continuous feeding via tube by owners for 4–6 weeks or for 10 days post vomiting, eating on their own and normal biochemical values • Monitor potassium and phosphorus • Monitor body weight and hydration • Hypoallergenic dietary management • Periodic evaluations until patient stabilizes Prevention/ Avoidance • Prevent anorexia (especially obese felines) • Monitor food intake in obese cats during times of stress or other disease processes • N/A Follow-Up Treatment Diagnosis Disease Antiemetic: metoclopramide Antibiotics: ampicillin, amoxicillin, metronidazole Lactulose Ursodeoxycholic acid: actigal Vitamin K therapy CHAPTER 6 / GENERAL MEDICINE 247 6 Table 6.26 / Gastroenterology: Hepatic Lipidosis and Inflammatory Bowel Disease (Continued) Follow-Up Disease Hepatic Lipidosis (Fatty Liver Disease) Inflammatory Bowel Disease (IBD) Complications • • • • • • • • • Prognosis • Grave if left untreated • 65% of patients recover with proper treatment • Good with continuous maintenance of remission and control of relapses • Course of disease tends to be progressive in prone breeds. • Caution: Avoid dextrose supplementation as it interferes with fat oxidation. • Majority of felines are obese before this disease process starts. • Vitamin K should be given IM at least 12 hours before biopsies. • Biopsy samples typically float when placed in formalin. • A hypoallergenic protein source refers to one to which the patient has not yet been exposed or a hydrolyzed diet. • The diet should also be void of artificial colorings, flavors, and preservatives. • Feed a novel protein source for 6 weeks while the GIT heals; then switch to another novel protein source. • Basenji, Soft-Coated Wheaton Terrier, and Shar pei Notes 6 Vomiting Tube dysfunction Hepatic failure Death Adverse drug reactions Anemia Malnutrition and dehydration Protein losing enteropathy Small intestinal bacterial overgrowth Table 6.27 / Gastroenterology: Megaesophagus Megaesophagus (Esophageal Hypomotility) Definition Megaesophagus is a segmental or diffuse hypomotility and dilation of the esophagus. There are three main causes: congenital, acquired idiopathic or secondary to another condition (e.g., myasthenia gravis, brain stem lesion, tetanus) Diagnosis Presentation Disease 248 Clinical Signs • Cough, dyspnea, emaciation, generalized muscle weakness or atrophy, halitosis, mucopurulent nasal discharge, regurgitation, salivation, weight loss Examination Findings • Pyrexia, neurologic deficits, pulmonary crackles, raspy breath sounds General • History/clinical signs • Palpation of dilated esophagus Laboratory • CBC: neutrophilia and left shift • Acetycholine receptor antibody titer: screen for myasthenia gravis Imaging • Radiographs, thoracic: distention of esophagus with air, fluid or food, aspiration pneumonia • Contrast study: ↓ movement and pooling of fluid Procedures • Fluoroscopy: ↓ strength and coordination or peristaltic contractions • Endoscopy: dilated esophagus, foreign body, neoplasia, and esophagitis SECTION THREE: DIAGNOSTIC SKILLS Table 6.27 / Gastroenterology: Megaesophagus (Continued) Follow-Up Treatment Disease Megaesophagus (Esophageal Hypomotility) General • Symptomatic • Supportive Medication • • • • Nursing Care • Nutritional support to ensure passage of food past dilated esophagus • ↑ Caloric density diet Patient Care • Offer small, frequent meals with patient in upright position for 10–15 minutes following meal. Prevention/ Avoidance • Diligent feeding rituals will increase life span. • Early detection of recurrent pneumonias Complications • Weight loss • Aspiration pneumonia Prognosis • Fair with diligent supportive care Notes Antibiotics for aspiration pneumonia: variable H2-blockers: sulcralfate Metoclopramide Prokinetic agents: cisapride 6 • Feeding small “meatballs” of canned food to a patient in an upright position often ↓ regurgitation. Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis Pancreatitis Peritonitis Definition Pancreatitis is inflammation of the pancreas that can be either acute or chronic. Chronic pancreatitis is often seen with morphological changes in the pancreas. It can be caused by obesity, ingestion of excessive fat, or multiple other disease processes. Peritonitis is a life-threatening condition that requires progressive medical management for resolution. Peritonitis is an inflammatory process involving all or part of the peritoneal cavity. Clinical Signs • Anorexia, depression, diarrhea, jaundice, panting, praying position, restlessness, tachypnea, trembling, vomiting, weakness • Diarrhea, praying posture, reluctance to move, tachypnea, tucked up abdomen, vomiting Examination Findings • Dehydration, pyrexia, cranial abdominal pain, and mass effect • Abdominal pain, dehydration, pyrexia, shock, tachycardia Presentation Disease CHAPTER 6 / GENERAL MEDICINE 249 Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis (Continued) Diagnosis Disease Pancreatitis Peritonitis General • History/clinical signs • Abdominal palpation: enlarged and painful pancreas • History/clinical signs • Abdominal palpation: pain or organomegaly Laboratory • CBC: neutrophilia with or without a left shift, leukocytosis, thrombocytopenia, anemia • Chemistry panel: ↑ amylase, lipase, ALP, ALT, bilirubin, BUN, creatinine, cholesterol, lipids, glucose, ↓ albumin, calcium (v) and azotemia (acute type) • Canine pancreatic lipase immunoreactivity (cPLI): ↑ value • Feline pancreatic lipase immunoreactivity (fPLI): ↑ value • TLI: ↑ value • CBC: neutrophilia with or without a left shift, leukocytosis, and anemia • Chemistry panel: ↑ amylase, lipase, ALT, AST, bilirubin, ↓ protein, glucose, potassium, electrolyte imbalances, and azotemia • Cytology, abdominal: degenerate neutrophils and intracellular bacteria • ± Culture: bacteria isolation and identification Imaging • Radiographs, thoracic: pulmonary edema or pleural effusion (rare) • Radiographs, abdominal: displacement of stomach and duodenum,↑ density, ↓ contrast gastric distention, static gas pattern, thickened and corrugated walls of the duodenum • Ultrasonography: irregular enlargement and abscesses of the pancreas, hyper- and hypoechoic changes, peripancreatic fluid accumulation • Contrast CT: identification and management • Radiographs, abdominal: free fluid or air, ↓ detail, ileus, distention of loops of bowel with fluid or gas • Iodinated contrast studies: GIT to locate perforation • Ultrasonography: free fluid, abscesses, masses and cause of peritonitis Procedures • Biopsy: confirmed diagnosis • Abdominocentesis General • • • • • • • • Medication • Analgesics: meperidine HCl and butorphanol • Antibiotics: ampicillin, cephalosporins, trimethoprim-sulfa, and enrofloxacin • Antiemetics: chlorpromazine, dolasetron, ondansentron • Corticosteroids (shock): prednisone • Glucagon • Somatostatin • Vasopression • Analgesics: variable • Antibiotics: penicillin, cephalosporins or aminoglycosides, ampicillin, enrofloxacin Nursing Care • NPO • Potassium supplementation • Complete rest and confinement • Standard postoperative • Limit activity. • Nutritional support Patient Care • After vomiting has stopped for 1–2 days, slowly reintroduce water followed by a gradual reintroduction of a high-carbohydrate diet. • Check CBC, chemistry profile, and urinalysis every 1–2 days, even in patients who are responding. Prevention/ Avoidance • Avoid fatty foods and dietary indiscretion. • Maintain optimum weight control. • Avoid corticosteroid treatment. • N/A Follow-Up Treatment 6 250 Symptomatic Supportive Fluid therapy Surgery: laparotomy SECTION THREE: DIAGNOSTIC SKILLS Supportive Fluid therapy Peritoneal lavage Surgery: laparotomy, correct primary etiology, lavage and drain placement Table 6.28 / Gastroenterology: Pancreatitis and Peritonitis (Continued) Disease Pancreatitis ↓ Protein and oncotic pressure Peritonitis Renal failure, acute Septic shock Thromboembolic disease Worsening pancreatitis Peritonitis • Herniation of abdominal contents • Adhesions • • • • • • Prognosis • Fatal without treatment • Poor with complications • Poor even with adequate treatment • Patients with recurrent pancreatitis may try a trial period of enzyme therapy. • Caution: Do not use povidone-iodine solution for lavage as it may be absorbed and produce toxic effects. • Use a contrast medium with minimal abdominal effects in case of leakage (e.g., iohexol). Follow-Up Complications Notes Table 6.29 / Gastroenterology: Protein-Losing Enteropathy and Vomiting Protein-Losing Enteropathy Vomiting Definition Protein-losing enteropathy is a disease of excessive loss of serum protein into the intestinal tract. It can be a primary GIT disease or the result of a generalized condition such as congestive heart failure, nephrotic syndrome, or metastatic neoplasia. Vomiting is the forceful, reflex expulsion of gastric or proximal small bowel contents from the oral cavity. Its duration can be acute or chronic (>14 days). Clinical Signs • Diarrhea, dyspnea • Anorexia, depression, hypersalivation, nausea, repeated swallowing, and licking of lips • Others depending of underlying disease Examination Findings • Ascites, edema, pleural effusion, thickened bowel loops • Abdominal distention or pain General • History/clinical signs • Abdominal palpation: intestines • History/clinical signs • Examination of vomitus Laboratory • • • • • • • • Diagnosis Presentation Disease CBC: +/− anemia and +/− lymphopenia Chemistry panel: ↓ albumin, globulin, calcium, and cholesterol Urinalysis: ↑ protein-to-creatinine ratio Fecal examinations: rule out parasites and bacterial overgrowth TLI and folate: results dependent on disease process Cobalamin: ↓ values Serum bile acids: assess hepatic function T4: ↑ values (feline) • Dependent on underlying condition CHAPTER 6 / GENERAL MEDICINE 251 6 Table 6.29 / Gastroenterology: Protein-Losing Enteropathy and Vomiting (Continued) Protein-Losing Enteropathy Vomiting Imaging • Radiographs, thoracic: rule out cardiac disease or fungal disease • Radiographs, abdominal: rule out fungal disease, tumors or intestinal obstruction • Contrast: tumor or bowel disease • Ultrasound: abdominal abnormalities or tumors • • • • Procedures • Endoscopy: mucosal visualization and biopsy • Endoscopy: stomach and proximal duodenum abnormalities General • • • • Symptomatic Supportive Blood or hetastarch transfusions Surgery: laparotomy for diagnostic full-thickness biopsies • Symptomatic • Fluid therapy • Surgery: exploratory laparotomy Medication • • • • • Antibiotics: metronidazole, tylosin, or sulfasalazine Chemotherapy: chlorambucil Corticosteroids: prednisone Diuretics: furosemide Immunosuppressive: azathioprine, cyclosporin • Antiemetic: metoclopramide, diphenhydramine, prochlorperazine, and chlorpromazine • Antisecretory: cimetidine, famotidine, rantidine, omeprazole • GI protectants: sulcralfate Nursing Care • Treated as outpatient • Standard postoperative • NPO Patient Care • Dietary modifications depending on underlying cause • Recheck body weight and protein concentrations every 7–14 days. • Monitor for reoccurrence of clinical signs. • After vomiting has stopped for 12 hours, slowly reintroduce water followed by a gradual reintroduction of a single protein and carbohydrate diet. • Wean back to regular diet over 4–5 days. Prevention/ Avoidance • Control inflammatory bowel disease • Avoid dietary indiscretion Complications • • • • • Dehydration • Electrolyte imbalances • Aspiration pneumonia Prognosis • Guarded • Excellent in mild cases and with proper treatment of severe cases • ↑ Risk of morbidity postoperative due to slow wound healing because of ↓ albumin, serosal patch graft may be necessary Types of vomiting • Undigested or partially digested food >12–16 hours old: delayed gastric emptying • Projectile vomiting: gastric or upper small bowel obstruction • Praying mantis position: gastrointestinal pain Physical appearance of vomit • Bile: gastroduodenal reflux • Fresh blood: recent bleeding in esophagus or stomach • Digested blood: ulcer disease • Mucus: concurrent irritation of stomach and intestines Follow-Up 6 Treatment Diagnosis Disease Notes 252 Diarrhea, severe Malnutrition, severe Respiratory difficulty Slow wound healing SECTION THREE: DIAGNOSTIC SKILLS Radiographs, thoracic: heartworm disease Radiographs, abdominal: foreign body, pancreatitis, or pyometra Contrast: foreign body Ultrasound: abdominal abnormalities or tumors HEMATOLOGY Table 6.30 / Hematology: Anemia and Disseminated Intravascular Coagulation Disease Anemia Nonregenerative Disseminated intravascular coagulation is a complex condition that is always secondary to another disease process. It is defined as an excessive activation of the clotting mechanism with complete consumption of clotting factors. Clinical Signs • Anorexia, collapse, depression, dyspnea, exercise intolerance, melena, tachypnea, weakness • Clinical signs of underlying disease • Dyspnea, melena, petechiae, spontaneous hemorrhage from orifices Examination Findings • Flea infestation, icteric, lymphadenopathy, pallor, petechiae, pyrexia, retinal hemorrhages, soft systolic murmur, splenomegaly, tachycardia • Pyrexia, subcutaneous hematoma and petechiae, tachycardia General • History/clinical signs • History/clinical signs Laboratory • CBC: ↑ MCV, ↓ PCV, MCHC, TP, leukopenia, thrombocytopenia • Urinalysis: ↑ blood, +/− bilirubin • Fecal analysis: hookworms and coccidia • ELISA: FeLV in-house screening • Cytology, bone marrow: erythroid hypoplasia • CBC: ↑ +/− MCHC, ↓ PCV, +/− MCV, TP, reticulocytosis, neutrophilia, thrombocytosis, nucleated RBCs, basophilic stippling (feline), spherocytes (canine, IMHA) • Chemistry panel: ↑ bilirubin • Fecal analysis: hookworms and coccidian • Corrected reticuloctye %: >1% • Cytology, bone marrow: erythroid hyperplasia • COOMBS test and ANA serology: + results • Slide agglutination test: + results indicate anemia is immune-mediated • CBC: thrombocytopenia, schistocytes, ↓ platelet count, fibrinogen levels, and presence of fibrin degradation products • Chemistry panel: ↑ BUN • Urinalysis: hematuria • FDP assay: + • Coagulation tests, PT, PTT, ACT: ↑ times • Latex agglutination test: ↑ value Imaging • Radiographs, abdominal: splenomegaly • Radiographs, thoracic: fluid • Radiographs, abdominal: fluid • N/A Procedures Treatment Regenerative Anemia is a decreased number of necessary RBC and is a primary bone marrow dysfunction. It can be caused by RBC loss, destruction, or depression of production. Anemia is typically broken down in two types: regenerative (loss and destruction) and nonregenerative (depression of production). Regenerative anemia can be immune-mediated, causing the destruction of RBCs and ending in immune-mediated hemolytic anemia (IMHA). Diagnosis Presentation Definition Disseminated Intravascular Coagulation (DIC) General • N/A • • • • Supportive Blood transfusions Fluid therapy Oxygen therapy • • • • Symptomatic Aggressive fluid therapy Blood transfusions Oxygen therapy CHAPTER 6 / GENERAL MEDICINE 253 6 Table 6.30 / Hematology: Anemia and Disseminated Intravascular Coagulation (Continued) Treatment Disease Disseminated Intravascular Coagulation (DIC) Nonregenerative Regenerative Medication • Immunosuppression: cyclosporine • Erythropoietin • Ferrous sulfate • Antibiotics: tetracyclines • Corticosteroids: prednisone, dexamethasone • Immunosuppression: azathioprine, cyclophosphamide, danazol, chlorambucil • Ferrous sulfate Nursing Care • • • • • Patient Care • Monitor CBC every 3–5 days until normal. • Monitor blood pressure. • Monitor PCV weekly until normal, then every 2 weeks for 2 months, then monthly. • Monitor CBC monthly during treatment. • Related to underlying disease Prevention/ Avoidance • Neuter cryptorchid males. • Monitor CBCs of patients receiving cancer drugs. • N/A • Related to underlying disease Complications • • • • • • • • • • Related to underlying disease Prognosis • Guarded to poor unless underlying disease can be diagnosed and treated • Recovery make take weeks to months. 6 Follow-Up Anemia Monitor for adverse reactions to drugs and transfusions. Monitor heart rate, respiratory rate, and temperature. Heat support Restrict activity Nutritional support Blood transfusion related Erythropoietin related Hemorrhage Sepsis Notes Cardiac arrhythmias DIC Embolisms Hypoxia Infections • • • • • • Antibiotics Anticoagulant: sodium heparin Corticosteroids (endotoxic shock) Cryoprecipitate Diuretics: mannitol NSAIDs: aspirin • • • • Avoid IM injections and neck leads. Strict confinement Feed soft foods. Use peripheral blood vessels from blood draws and catheter placement. • Poor to good prognosis with appropriate treatment • Guarded to poor prognosis with IMHA • Grave • IMHA: Old English Sheepdog, Cocker Spaniel, Poodle, Irish Setter, English Springer Spaniel, and Collie • Caution: Venipuncture sites can lead to excessive hematomas; place pressure wraps following procedure. Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease Disease Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia) von Willebrand Disease Definition Thrombocytopenia is a deficiency of platelets. Primary immunemediated is the destruction of platelets with no identifiable cause. It may occur as a single entity or as a combination of other immune-mediated diseases. von Willebrand disease is a bleeding disorder caused by a deficiency or dysfunction of the plasma protein (von Willebrand’s factor, vWF) used for normal platelet functions. This is the most common inherited bleeding disorder in dogs. 254 SECTION THREE: DIAGNOSTIC SKILLS Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease (Continued) Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia) von Willebrand’s Disease Clinical Signs • Anorexia, dyspnea, retinal and mucosal hemorrhages, epistaxis, hematochezia, melena, lethargy, vomiting, weakness • ↑ Hemorrhage from wounds and surgery sites, spontaneous hemorrhage from mucosal surfaces of oral and nasal cavities, GIT, and genitourinary tract Examination Findings • Murmur, pallor, pyrexia, tachycardia • Internal hemorrhage General • History/clinical signs • Patient response to treatment • History/clinical signs Laboratory • CBC: thrombocytopenia <50,000/μL, microthrombocytosis, neutrophilia or neutropenia, schistocytes, autoagglutination, anemia • Chemistry panel: mild ↑ ALT and ALP (v) and ↓ protein • Urinalysis: ↑ Protein and blood (rare) • Platelet count: thrombocytopenia, ↑ shift platelets, immature platelets • Cytology: bone marrow: ↑ megakaryocytes • Serology: erlichiosis, Rocky Mountain spotted fever, dirofilariasis and leptospirosis • ANA titer: + results • Coagulation profiles: ↓ clotting times • CBC: anemia, neutrophilia and a mild left shift and reticulocytosis after acute bleeding, thrombocytopenia, megathrombocytosis • Chemistry panel: ↑ ALT, AST • Buccal mucosa bleeding time: ↑ time • Toenail bleeding time: ↑ time • vWF antigen assay: ↓ values • Platelet function analyzer: ↑ time • Collagen binding assay • DNA testing: classifies affected and carriers • Radiographs, thoracic: tumors • Radiographs, abdominal: tumors • N/A Diagnosis Presentation Disease Imaging Treatment Procedures • N/A General • • • • Supportive Fluid therapy Blood transfusion Surgery: splenectomy • • • • Supportive Fluid therapy Hormonal therapy Blood transfusions Medication • Corticosteroids: prednisone, prednisolone, dexamethasone • Immunosuppressant: vincristine, cyclophosphamide, azathioprine, danazol, cyclosporine, leflunomide • H2-blockers: sulcralfate • Human immunoglobulin • Cryoprecipitate: a concentrated form of vWF and factor VIII • Desmopressin acetate: ↑ vWF and ↓ bleeding time Nursing Care • Treated as outpatient • Standard postoperative • Strict confinement • • • • Avoid IM injections, neck leads, trauma, etc. Strict confinement Feed soft foods Use peripheral blood vessels from blood draws and catheter placement CHAPTER 6 / GENERAL MEDICINE 255 6 Table 6.31 / Hematology: Thrombocytopenia and von Willebrand’s Disease (Continued) Follow-Up Disease 6 Thrombocytopenia, Immune-Mediated (IMT, Idiopathic Thrombocytopenic Purpura, ITP, Autoimmune Thrombocytopenia) von Willebrand’s Disease Patient Care • Strict confinement until normal platelet counts return • Monitor platelet counts periodically following recovery. • Monitor for hemorrhages for 48 hours post surgery. Prevention/ Avoidance • • • • • Neuter affected dogs. • Selective breeding based on DNA testing Complications • GI ulceration • CNS hemorrhage • Hemorrhagic shock • Hemorrhage Prognosis • Good with corticosteroid treatment • Depends on the concentration of the von Willebrand’s factor Avoid unnecessary vaccinations. Minimize stress. Avoid medications that are suspected of having caused initial IMT. OVH for intact females to prevent hormonal imbalances • Thyroid supplementation evidence exists that it may ↑ vWF concentration and ↓ bleeding tendency. • Hemorrhage is not generally observed until platelet count is <40 000/μL. • Doberman Pinscher, Scottish Terrier, Shetland Sheepdog, Golden Retriever, Pembroke Welsh Corgi, and Standard Poodle Notes INFECTIOUS DISEASES Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis Disease Presentation Definition 256 Brucellosis ZOONOTIC Ehrlichiosis A disease caused by Brucella canis.This bacterium is transmitted through ingestion or inhalation and can be found in the lymphatic system, genital tract, eye, kidney, and intervertebral discs. The most common rickettsial disease of dogs caused by Ehrlichia spp. Transmission is most commonly seen through the bite of the brown dog tick, Rhipicephalus sanguineus, or the Lone Star tick, Amblyomma americanum. Mostly found on the Gulf Coast, Eastern Seaboard, midwest, and California. Clinical Signs • Abnormal gait, anorexia, ataxia, exercise intolerance, weakness • Male: scrotal swelling or dermatitis, enlarged epididymis, testicular atrophy • Female: abortion, infertility, and vaginal discharge for 1–6 weeks postabortion • Acute: ataxia, dyspnea, exercise intolerance, oculonasal discharge • Chronic: dyspnea, epistaxis, pallor, spontaneous bleeding, weakness, weight loss Examination Findings • Anterior uveitis, ascites, corneal edema, epididymitis, lymphadenopathy, paralysis, paresis, pyrexia, spinal hyperesthesia, splenomegaly • Acute: lymphadenopathy, organomegaly, pyrexia, vestibular dysfunction • Chronic: arthritis, intermittent limb edema, neurologic signs, organomegaly, pyrexia, uveitis SECTION THREE: DIAGNOSTIC SKILLS Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis (Continued) Disease Ehrlichiosis General • Clinical signs • History/clinical signs • Ocular examination: retinal detachment and hemorrhage Laboratory • Chemistry panel: ↑ globulin and ↓ albumin • Urinalysis: ↑ protein, albumin • RSAT: accurate for negative dogs, detects infected dogs 3–4 weeks after infection • AGID: highly sensitive, detects infected dogs 4–12 weeks after infection • TAT/2ME-TAT: + titers, detects infected dogs 3–4 weeks after infection • Culture: B. canis identification • Cytology, lymph node: nonspecific reactive hyperplasia • Cytology, semen: >80% of sperm are morphologically abnormal, inflammatory cells • Culture, blood, urine, semen, vaginal discharge, aborted fetuses: Brucella isolation and identification • CBC: acute, thrombocytopenia, anemia (v), leukopenia and chronic, nonregenerative anemia, thrombocytopenia, lymphocytosis, pancytopenia, leukopenia or leukocytosis • Chemistry panel: acute, ↑ globulin, mild ↑ ALT, ALP, BUN, creatinine, ↓ albumin and chronic, ↑ globulin, BUN, creatinine, ↓ albumin • Urinalysis: acute, ↑ protein, specific gravity • IFA: titers >1:10 (2–3 weeks after exposure, titers not available for all species) • PCR, Erlichia test: +, identifying active infections after treatment • ACT: ↑ clotting times • Buffy coat analysis: Erlichia inclusions in WBCs • Cytology, bone marrow: acute, hypercellular, megakaryocytic, chronic, erythroid hyperplasia, ↑ mast cells Imaging • Radiography, spine: diskospondylitis, if found then check for Brucellosis • N/A Procedures • N/A • N/A General • Supportive • Supportive • Blood transfusion • Fluid therapy Medication • Antibiotics: minocycline, gentamicin, doxycycline, enrofloxacin, streptomycin • Anabolics: oxymetholone, nandrolone decanoate, danazol, stanozolol • Antibiotics: tetracycline, doxycycline, chloramphenicol, imidocarb diproprionate • Corticosteroids: prednisone, prednisolone Nursing Care • Treated as outpatient. • Restrict activity. Patient Care • Multiple courses of antibiotic treatment • Serologic titers monthly for 3 months, then at 6 months • Restrict activity in working dogs • Restrict activity. • Platelet count every 3 days until normal • Repeat serologic testing in 9 months; should be undetectable in 12 months. Prevention/ Avoidance • Neuter infected animals. • Quarantine and test all new dogs and breeding individuals. • Tick control and avoidance through sprays and spot-ons • Avoid tick-infested areas. Complications • Infertility • Sexual transmission • N/A Prognosis • Early detected ↑ response to therapy • Guarded if late detection • Excellent • Poor if bone marrow is severely hypoplastic Diagnosis Treatment Follow-Up Brucellosis ZOONOTIC CHAPTER 6 / GENERAL MEDICINE 257 6 Table 6.32 / Infectious Diseases: Brucellosis and Erlichiosis (Continued) Disease Notes Brucellosis ZOONOTIC • Transmission is following breeding or abortion, or following contact with semen, vaginal discharge, and urine by penetration of oronasal, conjunctival, or genital mucous membranes. • Lasts for 6–64 months • Low risk of human infection with proper hygiene, mild and easily treated Ehrlichiosis • Transmitted by the brown dog tick and transfusions. • Incubation period is 7–21 days. • German Shepard and Doberman Pinscher 6 Table 6.33 / Infectious Diseases: Rocky Mountain Spotted Fever and Salmon Poisoning Rocky Mountain Spotted Fever ZOONOTIC Salmon Poisoning Definition This is a tick-borne disease caused by Rickettsia rickettsii. It is the most important rickettsial disease in humans. Found on the East Coast, midwest, and Plains region. A rickettsial disease caused by Neorikettsia helminthoeca and found in the Pacific Northwest. Attacks the tissue of the small intestinal epithelium and associated lymph system. Clinical Signs • Abnormal gait, anorexia, ataxia, convulsions, depression, diarrhea, dyspnea, epistaxis, face and limb edema, lethargy, myalgia, weakness • Diarrhea, hypothermia, naso-ocular discharge, profound weight loss, vomiting Examination Findings • Anterior uveitis, arthritis, ascites, conjunctivitis, lymphadenopathy, ocular pain, petechial hemorrhages, pyrexia, scleral injection, tachycardia, vasculitis, vestibular signs • Conjunctivitis, lymphadenopathy, pyrexia, tachycardia General • History/clinical signs • Ticks recently removed from the dog • History/clinical signs • Recent ingestion of raw salmonoid fish meat Laboratory • CBC: eukocytosis with a left shift, +/− toxic neutrophils, monocytosis, mild anemia, thrombocytopenia • Chemistry panel: ↑ ALT, ALP, BUN, creatinine, cholesterol, albumin, ↓ sodium, chloride, protein, metabolic acidosis • Urinalysis: ↑ protein, blood • Micro-IFA: titers >1 : 128 • Direct immunofluorescence with skin biopsies: rickettsial antigens as early as 3–4 days postinfection • ACT: ↑ clotting times • Urinalysis: ↑ specific gravity • Direct fecal smear: operculated fluke eggs (Nanophyetus salminicola) • Giemsa-stained FNA of lymph nodes: hyperplasia with intracytoplasmic rickettsial bodies in macrophages Imaging • N/A • N/A Procedures • N/A • N/A Diagnosis Presentation Disease 258 SECTION THREE: DIAGNOSTIC SKILLS Table 6.33 / Infectious Diseases: Rocky Mountain Spotted Fever and Salmon Poisoning (Continued) Follow-Up Treatment Disease Rocky Mountain Spotted Fever ZOONOTIC Salmon Poisoning General • Supportive • Blood transfusions • Fluid therapy • Supportive Medication • Antibiotics: tetracycline, doxycycline, chloramphenicol, imidocarb diproprionate • Antibiotics: tetracyclines, chloramphenicol • Anticestodal: praziquantel Nursing Care • Restrict activity. • Restrict activity. Patient Care • Monitor platelet count every 3 days until normal. • Micro-IFA titers 2–4 weeks after initial titer: 2–4 fold rise in titer • Restrict activity. • Monitor temperature, hydration, electrolytes, and acid-base balances. Prevention/Avoidance • Tick and rodent control • Using gloves or instruments, check daily for ticks and remove entire tick if found. • Prevent eating of raw fish (salmonoid type). • Thoroughly cook or freeze fish. Complications • N/A • N/A Prognosis • Good if early diagnosis and treatment • Poor if in later stages with CNS disease • Good with treatment • Caution: Handling of an infected tick may result in transmission of the disease even without attachment. • Transmitted by the American deer tick, wood tick, Lone Star tick, and transfusions • The tick must be attached for 5–20 hours to infect dogs. • Primary host is rodents and rabbits • Incubation time is 2 days to 2 weeks. • High titers can be seen for 1 year following successful treatment. • Transmitted through eating raw salmon or related fish carrying encysted forms of the fluke N. salminicola. • Incubation of 5–21 days Notes 6 Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis Disease Presentation Definition Tetanus Toxoplasmosis ZOONOTIC Disease caused by Clostridium tetani which is found in the soil and as part of the normal bacterial flora of the intestinal tract of mammals. This disease, caused by the protozoan parasite, Toxoplasma gondii, can invade and multiply in any cell in the body. Clinical Signs • Ataxia, convulsions, disoriented, dyspnea, ears erect, forehead wrinkled, hypersalivation, lips retracted, localized or generalized muscle rigidity, seizures, stiffness, tetanic spasms, trismus, walking difficulty, weakness • Subclinical most of the time • Anorexia, ataxia, depression, diarrhea, dyspnea, exercise intolerance, lethargy, paralysis, paresis, seizures, stiff gait, tremors, vomiting, weakness, weight loss Examination Findings • Altered heart and respiratory rates, hyperventilation, laryngeal spasms, pyrexia, tachycardia • Abdominal effusion and pain, anterior and posterior uveitis, blindness, icterus, myocarditis, pancreatitis, pneumonia, pyrexia CHAPTER 6 / GENERAL MEDICINE 259 Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis (Continued) Disease Tetanus • Clinical signs • Recent wound (esp. with high levels of necrosis and anaerobic conditions) • Clinical signs Laboratory • Chemistry panel: ↑ CK (CPK) • CBC: leukopenia with degenerative left shift or neutrophilic leukocytosis and nonregenerative anemia • Chemistry panel: ↑ bilirubin, bile acids, AST, ALT, ALP, GGT, creatinine, amylase, lipase, ↓ albumin • Urinalysis: ↑ protein and bilirubin • IgM: elevated 2 weeks postinfection, >1 : 256 or >1 : 64 and negative IgG indicates active infection • IgG: elevated 2–4 weeks postinfection, >1 : 512 active infection or 2–4 fold rising titer 2 weeks apart • Antigen serum titers: + 1–4 weeks postinfection Imaging • N/A • Radiographs, abdominal: hepatomegaly, effusion • Radiographs, thoracic: effusion, patchy alveolar and interstitial pulmonary infiltrates Procedures • N/A • ECG: arrhythmia, cardiac irregularity General • Supportive • Fluid therapy • Wound management: debridement, H2O2 flushing, cleaning • Supportive • Fluid therapy Medication • Antibiotics: penicillin G or metronidazole • Anticonvulsants/muscle relaxants: diazepam, chlorpromazine, acetylpromazine, phenobarbital, pentobarbital, methocarbamol • Tetanus antitoxin • Antibiotics: clindamycin, pyrimethamine, trimethoprimsulfonamide • Folic acid, yeast • Ophthalmic drops: 1% prednisone Nursing Care • Keep patient in a dark quiet area and do not disturb. • Provide soft bedding and rotate every 4 hours to prevent decubital sores and lung congestion. • Prevent urinary and fecal retention with urinary catheterization and enemas. • Nutritional support: force feeding is not advised because it may cause tetanic state. • Monitor blood pressure and ECG. • Typically treat as outpatients. • Confine patients with neurologic signs. Patient Care • N/A • Examine 2 and 14 days post initiation of treatment for improvement. • Provide a high-quality diet, biannual physical examinations, annual blood work, vaccines, and prompt attention to illness. Diagnosis General Follow-Up Treatment 6 260 Toxoplasmosis ZOONOTIC SECTION THREE: DIAGNOSTIC SKILLS Table 6.34 / Infectious Diseases: Tetanus and Toxoplasmosis (Continued) Follow-Up Disease Tetanus Toxoplasmosis ZOONOTIC Prevention/ Avoidance • Prevent skin wounds: maintain clean and safe runs and yards. • Give proper wound care management. • Aseptic surgical technique • Prevent ingestion of raw meat, bones, viscera, or unpasteurized milk. • Prevent free roaming to hunt prey or access to the housing of food-producing animals. Complications • N/A • N/A Prognosis • Extremely guarded when severely affected • Guarded: can be become carriers and relapse clinically if immunocompromised • Clinical signs show up 5 days to 3 weeks later. • Death is from respiratory dysfunction. • Animals can be pretested for anaphylactic reaction to the antitoxin by giving an intradermal injection first and monitoring for 30 minutes. • Caution: Disease can be transmitted to an unborn fetus by an infected human mother. • Transmitted by ingesting infected animal tissues, cat feces, and transplacental infection • Excrete eggs 3–10 days after infection for 1–2 weeks: can shed again if stressed. • Oocysts must first sporulate to become infectious. • Oocysts can last in the soil for >1 year. Notes 6 MUSCULOSKELETAL Table 6.35 / Musculoskeletal: Arthritis Disease Arthritis Acute Diagnosis Presentation Definition Degenerative Joint Disease (DJD, Osteoarthritis) There are two types of clinically diagnosed arthritis: degenerative and acute inflammatory. Acute arthritis is a pathogenic organism within the closed space of a joint and is broken down into 3 types: septic, traumatic, and immune-mediated. DJD is a progressive deterioration, characterized by a loss of hyaline cartilage matrix and death of chondrocytes. There is no cure for DJD; treatment is based on alleviating clinical signs and slowing progression. Clinical Signs • Joint swelling, lameness, pain, reluctance to jump or climb stairs, stiff gait • Abnormal gait, ataxia, exercise intolerance, ↑ lameness following moderate to heavy exercise, stiff upon rising after recumbency, swelling, walking difficulty Examination Findings • Crepitus, laxity, pain, ↓ ROM • Crepitus, edema, laxity, muscle atropy, pain General • History/clinical signs • Joint palpation and manipulation • History/clinical signs • Joint palpation CHAPTER 6 / GENERAL MEDICINE 261 Table 6.35 / Musculoskeletal: Arthritis (Continued) Disease Degenerative Joint Disease (DJD, Osteoarthritis) Laboratory • • • • • • • • • • Synovial fluid analysis: ↑ mononuclear cells (e.g., lymphocytes), protein, ↓ viscosity, cell count (compared to septic or inflammatory arthritides) • Mucin clot test: clot poor Imaging • Radiograph, affected joint: joint capsular distension, soft tissue thickening, joint effusion and bone lysis • Radiograph, affected joint: osteophytes, subchondral sclerosis, narrowed joint space, and remodeling of subchondral bone/ epiphyses Procedures • Arthrocentesis • Arthrocentesis General • Supportive • Surgery: arthrotomy, reconstructive procedures, arthrodesis • Supportive • Surgery: resection arthroplasty, joint replacement, arthrodesis Medication • Antibiotics: variable • Chondroprotective agents: Adequan, glucosamine with chondroitin sulfate • Corticosteroids: prednisone or triamcinolone • Methyl sulfonyl methane • Misoprostol • NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin • • • • Nursing Care • Standard postoperative • Treated as outpatient • Standard postoperative • Treated as outpatient Patient Care • Moderate activity, but restricted to a level that minimizes discomfort • Strict confinement with acutely painful episodes • Obesity control • Physical therapy: hot/cold treatment, swimming, ROM exercises and massage • Weight control • Encourage moderate and consistent exercise (e.g., swimming—low impact) Prevention/ Avoidance • Maintain appropriate weight control. • Early recognition to prevent proceeding to secondary condition • Maintain proper weight control. • Early use of glucosamine with chondroitin sulfate to slow progression Complications • Nonambulatory • DJD • Osteomyelitis • Nonambulatory Prognosis • Good with septic form • Fair to guarded with immune-mediated form • Progressive Diagnosis Acute Follow-Up Treatment 6 262 Arthritis CBC: leukocytosis, neutrophilia Urinalysis: ↑ protein ANA test: + results Tick-borne agent serology: + results Synovial fluid analysis: ↑ WBCs and bacteria Biopsy, synovial: neoplasia Cytology, synovial: ↑ WBCs, turbidity, bacteria Culture, synovial: bacteria, yeast, fungi, additional organisms Mucin clot test: clot poor SECTION THREE: DIAGNOSTIC SKILLS Chondroprotective agents: glucosamine with chondroitin sulfate Corticosteroids: prednisone or triamcinolone Misoprostol NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin Table 6.36 / Musculoskeletal: Cruciate Disease and Hip Dysplasia Cruciate Disease (Cranial Cruciate Rupture) Hip Dysplasia Definition Cruciate disease results in a partial or complete instability of the stifle joint. The tearing of the anterior cruciate ligament can be done acutely or as a degenerative process. Hip dysplasia is the most common condition of the hip joint and cause of osteoarthritis. Hip dysplasia is a faulty development of the hip joint contributing to joint laxity and subluxation early in life. Joint instability occurs as muscle development and maturation lag behind the rate of skeletal growth. Clinical Signs • Abnormal gait, acute or intermittent lameness, ataxia, walking difficulty • Abnormal gait, ataxia, exercise intolerance, hindlimb lameness Examination Findings • Deformed stifle joint, edema, joint effusion, muscle atrophy of hindlimb musculature, swelling • Barden’s sign, Barlow’s sign, crepitus, joint laxity, muscle atrophy, Ortolani + test, pain, ↓ ROM General • History/clinical signs • Joint palpation: + anterior drawer sign • History/clinical signs • Joint palpation Laboratory • Synovial fluid analysis: rule out sepsis and immune-mediated disease • N/A Imaging • Radiograph, stifle joint: joint effusion with capsular distention, periarticular osteophytes, compression of infrapatellar fat pad and calcification of cruciate ligament • MRI: confirmation and severity of disease • Radiographs, skeletal: joint subluxation of femoral head, flattening of femoral head, shallow acetabulum, periarticular osteophytes, or widening of joint space between femoral head and cranial acetabulum Procedures • Arthrocentesis • Arthroscopy: confirmation and severity of disease • N/A General • Symptomatic • Cage rest • Surgery: tibial plateau leveling osteotomy (TPLO), “over-the-top” fascia lata graft, fibular head transposition imbrication procedure, extracapsular reinforcing procedures • Surgery: triple pelvic osteotomy (TPO), femoral head and neck excision arthroplasty, pectineal myectomy, intertrochanteric osteotomy, or total hip replacement Medication • Chondroprotective drugs: Adequan, glucosamine with chondroitin sulfate • Misoprostol • NSAIDs: aspirin, carprofen, deracoxib, etodolac, firocoxib, meloxicam, tepoxalin • Analgesics: variable • Chondroprotective agents: Adequan or glucosamine with chondroitin sulfate • Corticosteroids: prednisone, triamcinolone (short-term use) • Misoprostol • NSAIDs: aspirin, piroxicam, carprofen, etodolac, phenylbutazone, meclofenamic acid Nursing Care • Placement of Robert Jones bandage • Postoperative radiographs to evaluate surgery • Physical therapy • Restrict activity. Treatment Diagnosis Presentation Disease 6 CHAPTER 6 / GENERAL MEDICINE 263 Table 6.36 / Musculoskeletal: Cruciate Disease and Hip Dysplasia (Continued) Follow-Up Disease 6 Cruciate Disease (Cranial Cruciate Rupture) Hip Dysplasia Patient Care • Cryotherapy • Physical therapy: ROM exercises and massage • Restricted activity: leash only exercise and no use of stairs for 3 months postoperative • Reradiograph at 8 weeks • Full exercise by 6–9 months postoperative • Control obesity • Restrict activity. • Monitor radiographs to assess degeneration. Prevention/ Avoidance • Selective breeding • Maintain proper weight control. • Selective breeding • Nutritional manipulation for large breed dogs during growth and development • Avoid excessive exercise. Complications • Osteoarthritis • Osteoarthritis • Nonambulatory Prognosis • Excellent with surgery • Good depending on severity of disease Notes • Joint is palpated for drawer motion, movement of tibia relative to femur during the tibial compression test, and thickening of joint capsule. • In 30–40% of canines, the opposite cranial cruciate ligament ruptures within 17 months. • Rottweiler and Labrador Retriever Table 6.37 / Musculoskeletal: Osteochondrosis and Osteomyelitis Osteochondrosis or Osteochondritis Dessicans (OCD) Osteomyelitis Definition Osteochondrosis is a defect in endochondral ossification leading to an excessive retention of cartilage. This defect may occur in any limb joint. Ununited anconeal process and fragmented coronoid process may also be seen along with osteochondrosis or separately. It is often seen in animals between 5–10 months of age. Osteomyelitis is an infection of the bone and its soft tissue elements and membranes. Infectious organisms often complicate an existing condition leading to an infection that is very difficult, and sometimes impossible, to treat. Clinical Signs • Abnormal gait, anorexia, cachexia, forelimb or hindlimb lameness, reluctance to exercise, walking difficulty • Anorexia, cachexia, depression, exercise intolerance, lameness, lethargy, rising difficulty, weakness Examination Findings • Arthritis, crepitus, hyperextension pain, joint effusion, joint pain, muscle atrophy, swelling • Edema, inflammation, intermittent draining tracts, pain, paralysis, paresis, pyrexia, swelling, tachycardia General • History/clinical signs • Joint palpation • History/clinical signs • Skeletal palpation • Neurologic examination Diagnosis Presentation Disease 264 SECTION THREE: DIAGNOSTIC SKILLS Table 6.37 / Musculoskeletal: Osteochondrosis and Osteomyelitis (Continued) Follow-Up Treatment Diagnosis Disease Osteochondrosis or Osteochondritis Dessicans (OCD) Osteomyelitis Laboratory • Joint tap and fluid analysis: confirms involvement and mononucleated cells • CBC: neutrophilic leukocytosis • Cytology: toxic neutrophils, phagocytized bacteria or fungal organisms • Culture: bacteria isolation and identification and sensitivity Imaging • Radiographs, skeletal: joint abnormalities, bone lengths, arthritis, sclerosis of underlying bone or bone flap/fragments (joint “mice”) • CT/MRI: location and severity of lesion • Arthrogram: identifies cartilage flap or loose cartilage via contrast enhanced joint radiographs after intraarticular injections • Radiographs, skeletal: soft tissue swelling, bone resorption, sclerosis, bone sequestra, fracture nonunion, cortical thinning, widening of fracture gap, reactive periosteal new bone, foreign bodies, or fungal lesions • Contrast: sinus location and severity, foreign bodies • Radionuclide imaging: detecting osteomyelitis Procedures • Arthroscopy: confirming cartilage lesion • N/A General • Symptomatic • Surgery: arthrotomy or arthroscopy • Symptomatic • Wound management: debridement, drainage and irrigation • Surgery: sequestrectomy, amputation, bone grafts, or biopsy Medication • Analgesics • NSAIDs • Antibiotics: variable Nursing Care • Cryotherapy postoperative • Place modified Robert Jones bandage. • Sterile dressing applied to surgical wounds left to close by 2º intention. • Irrigate daily with sterile saline. Patient Care • Cryotherapy for 15–20 minutes 3 times daily for 3–5 days if no bandage placed • Physical therapy: ROM exercises • Restrict activity for 4 weeks, then gradually increase to normal activity over the next 4 weeks. • Reradiograph 4–6 weeks postoperative • Obesity management • Monitor radiographs for fracture healing. Prevention/ Avoidance • Selective breeding • Maintain proper weight control. • Nutritional manipulation for large-breed dogs during growth and development • Proper wound and fracture management Complications • Osteoarthritis • Disuse atrophy • Recurrence and relapse • Limb deformity or impaired function • Neurologic disease Prognosis • Good with early surgical repair (forelimb) • Guarded with stifle or tarsal OC • Good with acute disease • Poor with chronic disease • Great Dane, Labrador Retriever, Newfoundland, Rottweiler, Bernese Mountain Dog, English Setter, and Old English Sheepdog • Saint Bernard, German Shepard, Labrador Retriever, Golden Retriever, and Rottweiler Notes CHAPTER 6 / GENERAL MEDICINE 6 265 Table 6.38 / Musculoskeletal: Patella Luxation and Panosteitis Patellar Luxation, Medial Panosteitis (Enostosis) Definition Medial patellar luxation is generally a concern of small breed dogs. It is typically a congenital or developmental malformation of the stifle joint causing the patellar to displace from the femoral trochlea. Luxations are graded on a scale of I–IV, which allows guidance of treatment options. Panosteitis is a disease of young large-breed dogs that begins in the medullary bone marrow in the region of the nutrient foramen. Its cause is unknown. It gives intermittent lameness of one or multiple limbs. The disease is self-limiting, but its clinical signs will remain for months. Clinical Signs • Abnormal gait, ataxia, intermittent lameness of hindlimb, skipping, walking difficulty • Anorexia, ataxia, cachexia, depression, forelimb and hindlimb lameness, lethargy, shifting leg lameness, walking difficulty Examination Findings • Arthritis, pain, stifle joint deformity • Pain on palpation of diaphysis, pyrexia General • History/clinical signs • Patella palpation: laxity • History/clinical signs • Bone palpation Laboratory • N/A • CBC: eosinophilia (v) Imaging • Radiographs, hindlimb: bowing and/or torsion of tibia or femur and shape of femoral trochlea • Radiograph, skeletal: ↑ density, progressive mottling and radiopacity within the medullary cavity, new bone formation and thickened bone cortices • Scintigrams, bone: bone lesions Procedures • N/A • N/A General • Supportive • Symptomatic • Surgical: trochleoplasty, trochlear sulcoplasty, recession sulcoplasty, trochlear chondroplasty, chondroplasty, wedge recession, patelloplasty or tibial tuberosity translocation • Supportive Medication • Analgesics • Chondroprotective agents: Adequan or glucosamine with chondroitin sulfate • Corticosteroids: prednisone (short-term use) • Misoprostol • NSAIDs: aspirin, carprofen, etodolac, piroxicam • • • • Nursing Care • Cryotherapy immediately postoperative then 15–20 minutes daily for 3–5 days if no bandage • Placement of Robert Jones bandage • Physical therapy: ROM exercises and swimming • Treated as outpatient Patient Care • Restricted activity: leash only exercise and no use of stairs for 3 months postoperative • Full exercise by 6–9 months postoperative • Correct obesity • Restrict activity • Recheck lameness every 2–4 weeks for more serious orthopedic problems Presentation Disease Follow-Up Treatment Diagnosis 6 266 SECTION THREE: DIAGNOSTIC SKILLS Analgesics Corticosteroids: prednisone Misoprostol NSAIDs: aspirin, piroxicam, carprofen, etodolac Table 6.38 / Musculoskeletal: Patella Luxation and Panosteitis (Continued) Follow-Up Disease Patellar Luxation, Medial Panosteitis (Enostosis) Prevention/ Avoidance • Selective breeding • Maintain proper weight control • N/A Complications • Recurrence following surgery • DJD • N/A Prognosis • Excellent with surgery • Excellent • Miniature and Toy Poodle, Yorkshire Terrier, Pomeranian, Pekingese, Chihuahua, and Boston Terrier • German Shepard, Irish Setter, Saint Bernard, Doberman Pinscher, Airedale, Basset Hound, and Miniature Schnauzer Notes 6 NEUROLOGY Table 6.39 / Neurology: Encephalitis and Epilepsy Encephalitis Epilepsy Definition Encephalitis is an inflammatory disease of the brain with random progression. The causes of this condition are wide ranging from breed predilections to infectious diseases to viral, protozoan, fungal, and bacterial infections. The clinical signs, diagnosis, and treatment are all dependent on determining the underlying disease. Epilepsy is a condition of recurring seizures regardless of their cause. Primary epilepsy has no known cause and may be genetic/ hereditary. Secondary epilepsy is acquired through brain injury and/or inflammation. Clinical Signs • Dependent on underlying disease • Aggression, ataxia, behavioral changes, circling, depression, head tilt, pacing, paralysis, photophobia, seizures, tremors, vomiting 3 Stages of Seizures • Aura: immediately preceding seizure, restlessness, crying and hiding • Ictus: actual seizure, lasting <2–5 minutes, stiff, muscle spasms, chomps its jaw, salivates profusely, urinates, defecates, vocalizes and paddles with all four paws • Postictus: immediately following seizure – lasting <30 minutes, behavioral changes, weakness, blindness, hungry, thirsty, depressed, pacing, or tired Examination Findings • Abnormal heart and respiratory rates, corneal changes, nystagmus, pulmonary abnormalities, pyrexia • Postictus signs General • History/clinical signs • Neurologic examination • History/clinical signs • Neurologic examination Laboratory • • • • • • N/A Diagnosis Presentation Disease CBC: leukocytosis and dependent on underlying disease Chemistry panel: ↑ protein, creatine kinase CSF analysis: ↑ WBCs, protein, fungi, bacteria CSF titers: + results Serology: antibody recognition and identification CHAPTER 6 / GENERAL MEDICINE 267 Table 6.39 / Neurology: Encephalitis and Epilepsy (Continued) Diagnosis Disease Encephalitis Epilepsy Imaging • Radiographs, thoracic: lung abnormalities • Radiographs, skull: sinusitis or rhinitis (cryptococcosis) • CT/MRI: tumor • • • • • Procedures • EEG: diffuse multifocal cerebral involvement • Ophthalmoscopy: retinitis, chorioditis, uveitis, or vasculitis of retinal vessels • EEG: tumor, inflammation or metabolic disease • Ophthalmoscopy: retinitis, chorioditis, uveitis, or vasculitis of retinal vessels General • Symptomatic • Supportive • Radiation therapy • • • • Medication • • • • • Dependent on underlying disease Antibiotics: enrofloxacin, clavamox Corticosteroids: dexamethasone Fungal: itraconazole or fluconazole Lomustine Acute (IV/IN) • Anticonvulsants: diazepam, lorazepam, midazolam, phenobarbital, sodium pentobarbital, felbamate, zonisamide • Propofol Chronic (oral) • Anticonvulsant: gabapentin, phenobarbital, felbamate, potassium bromide Nursing Care • • • • Dependent on underlying disease Monitor neurologic functions. Frequent turning to prevent decubital sores and pulmonary edema Cold water, alcohol baths, or ice packs for hyperthermia • Constant monitoring for seizures, hyperthermia • Cold water, alcohol baths, or ice packs for hyperthermia Patient Care • Monitor neurologic functions. • Monitor blood work dependent on underlying disease. • Avoid swimming. • Monitor CBC, chemistry panel, urinalysis, phenobarbital, bromide, bile acids annually • Maintain a log of all seizure activity and review biannually with veterinarian. Prevention/ Avoidance • Tick control • Vaccinations • Proper wound management • Castrate affected animals. • Maintain antiseizure medication. Complications • Dependent on underlying disease • Death • Phenobarbital complications • Status epilepticus Prognosis • Variable: dependent on underlying disease • Many forms are lethal • Proper treatment gives ↓ seizure frequency Follow-Up Treatment 6 268 SECTION THREE: DIAGNOSTIC SKILLS Radiographs, thoracic: tumors Radiographs, abdominal: tumors Radiographs, skull: hydrocephalus, trauma or tumor CT: tumor, inflammation or granulomas MRI: tumor, inflammation Symptomatic Oxygen therapy Ocular compression Fluid therapy: do not give lactated Ringer’s in patients receiving potassium bromide Table 6.39 / Neurology: Encephalitis and Epilepsy (Continued) Disease Encephalitis Epilepsy Notes • Caution: Chosen drugs must be able to cross the blood-brain barrier. • Determining the underlying cause is critical to the patient’s survival. • Ocular compression is the gentle compression of the globe into the orbit by digital pressure over the upper lid for 10–60 seconds at 5-minute intervals. • Most seizures occur while sleeping or at rest, often at night or in early morning. • Do not stop medications abruptly as it may cause seizures; slowly reduce over 4–8 weeks (taper gradually). • German Shepard, Irish Setter, Miniature Poodle, Siberian Husky, Beagle, Cocker Spaniel, Labrador Retriever, Keeshond, and Miniature Schnauzer 6 Table 6.40 / Neurology: Intervertebral Disc Disease and Meningitis Intervertebral Disc Disease Meningitis Definition Intervertebral disc disease is an age-related condition affecting an individual disc or discs. This condition may lead to protrusion or extrusion of the disc leading to compression of the spinal cord, nerve roots, or meninges. The process can be either a degenerative or infectious process (diskospondylitis). Bacterial infection of the meninges is the cause of meningitis. It can be the result of septicemia, local invasion, or bite wounds. Secondary inflammation of the brain or spinal cord may also be seen with meningitis. Clinical Signs • Abnormal gait, ataxia, crying when touched, paresis or paralysis of some or all limbs, reluctance to move or jump, stiff or hunched stance/appearance, urinary incontinence, walking difficulty • Ataxia, cachexia, convulsions, depression, dyspnea Examination Findings • Edema, pain, Schiff-Sherrington syndrome • Ataxia, cervical pain and rigidity, edema, hyperesthesia, nasal, sinus or inner ear infection, mild paresis, pyrexia, tachycardia, tremors General • History/clinical signs • Spine palpation • History/clinical signs • Neurologic examination Laboratory • Urinalysis: leukocytes, ↑ protein, bacteria • CSF analysis: inflammatory cells and infectious agents • • • • • Diagnosis Presentation Disease CBC: leukocytosis Chemistry panel: ↑ globulin Urinalysis: pyuria, ↑ bacteria Serology tests: + Cytology, skin, eyes, nasal discharge and sputum: bacterial, fungal, protozoan, rickettsial, or viral • CSF analysis: bacteria, neutrophilic pleocytosis, protein CHAPTER 6 / GENERAL MEDICINE 269 Table 6.40 / Neurology Intervertebral Disc Disease and Meningitis (Continued) Disease Diagnosis Imaging Intervertebral Disc Disease Meningitis • Radiographs, spine: narrowed, wedge-shaped disc space, small intervertebral foramen, collapsed articular facets or mineralized disc material in the spinal cord, intervertebral foramen or vertebral endplate lysis or sclerosis • CT/MRI: location and severity of disc lesion, spinal cord edema • Myelography: location and severity of disc lesion • Radiographs, spine: bony infection • Radiographs, skull: sinus, nasal cavity, or ear infection • MRI/CT: ↓ opacity of cerebral hemisphere, lack of contrast Procedures Follow-Up Treatment 6 General • • • • Medication • Corticosteroids: prednisone, prednisolone or methyl prednisolone succinate • • • • Nursing Care • Careful handling of patients to prevent further trauma: protect the spine during any movement • Nutritional support • Monitor for worsening neurological signs. • Monitor urine output and defecation. • Turn recumbent patients at least every 4 hours and keep well padded. • Intensive care monitoring • Restricted activity Patient Care • Restrict activity. • Physical therapy: ROM exercises, hydrotherapy, start 2 weeks postoperative • Monitor urinalysis in nonambulatory patients. • Use harnesses to keep pressure off cervical discs. • Obesity management • Monitor for neurologic signs, fever, systemic signs, and leukocytosis. Prevention/ Avoidance • Maintain proper weight control. • Avoid strenuous exercise with prone breeds. • Treat local infections early and thoroughly to prevent spread of infection to the CNS. Complications • Recurrence of pain • Irreversible damage to the brain and spinal cord • DIC Prognosis • Excellent with surgery • Variable dependent on degree of infection and inflammation Notes 270 • N/A Symptomatic Cage rest for 2 weeks Acupuncture Surgery: laminectomy, hemilaminectomy, durotomy, decompression • Caution: Corticosteroids should not be used with diskospondylitis. • Caution: Do not use corticosteroids and NSAIDs together due to GIT hemorrhage. • For confinement to work, it must be strict with only leash walks to eliminate. • Beagle, Toy Poodle, Dachshund, Doberman Pinscher, and all chondrodystrophic breeds SECTION THREE: DIAGNOSTIC SKILLS • Symptomatic • Supportive • Fluid therapy Antibiotics: variable Anticonvulsants: diazepam or phenobarbital Corticosteroids: dexamethasone, prednisolone Diuretics: mannitol (osmotic type) Table 6.41 / Neurology: Myasthenia Gravis and Myelopathy Myasthenia Gravis Myelopathy (Degenerative Myelopathy) Definition Myasthenia gravis is associated with autoantibodies directed at nicotinic acetylcholine receptors (AChRs). This leads to a loss of AChRs, which impairs neuromuscular transmission and causes muscle weakness and episodic collapsing. Myelopathy is a degenerative process affecting the myelin and axons of the spinal cords. This slow, progressive problem has no known cause but is limited to the hindlimbs. There is no known treatment; it remains to be only supportive. Clinical Signs • Abnormal gait, body trembling, dysphagia, excessive drooling, dysphonia, dyspnea, muscle weakness, paresis/paralysis, regurgitation • Abnormal gait, ataxia, crossing over of hindlimbs, knuckling, scuffing of hindlimbs, swaying when turning, walking difficulty, weakness, worn toenails Examination Findings • Masticatory dysfunction, ventroflexion of head • Muscle atrophy General • History/clinical signs (episodic) • Neurologic examination • History/clinical signs • Neurologic examination Laboratory • • • • • Chemistry panel: ↑ CK Thyroid and adrenal function tests ANA assay: + result Serum antibodies against nicotinic AChRs: + result Edrophonium chloride challenge test: ↑ muscle strength following injection • Edrophonium response test: + • Electrodiagnostic evaluation: location and severity of disease • CSF analysis: ↑ protein, WBCs Imaging • Radiographs, thoracic: megaesophagus, cranial mediastinal mass, aspiration pneumonia • Radiographs, thoracic: metastasis and tumors • Radiographs, abdominal: same as above • Radiographs, spine: ossification, spondylosis or narrowed intervertebral disc space • MRI: to rule out IVDD Procedures • Fluoroscopy: dysfunction of swallowing • N/A General • • • • • Supportive Medication • Anticholinesterase drugs: pyridostigmine bromide or neostigmine • Corticosteroids: prednisone • Cyclophosphamide • Aminocaproic acid (v) • N-Acetylcysteine (v) • Vitamin supplements: vitamin C, E Nursing Care • Nutritional support • Treated as outpatient Patient Care • Feed animal in an upright position and ensure the animal remains upright for at least 10 minutes after eating. • Feed different consistencies of food to determine which works best. • Radiograph every 4–6 weeks to monitor megaesophagus. • Recheck AChR antibody titers every 6–8 weeks until normal. • Keep as active as possible to delay onset of nonambulatory state. Nonambulatory • Cart, slings for mobility • Avoid decubital sores • Urinary catheter • Vitamin supplementation Follow-Up Treatment Diagnosis Presentation Disease Supportive Fluid therapy Oxygen therapy Surgery: feeding tube placement or tumor removal 6 CHAPTER 6 / GENERAL MEDICINE 271 Table 6.41 / Neurology: Myasthenia Gravis and Myelopathy (Continued) Follow-Up Disease Myasthenia Gravis Myelopathy (Degenerative Myelopathy) Prevention/ Avoidance • N/A • N/A Complications • Aspirate pneumonia • Third-degree heart block • Respiratory arrest • Decubital sores • Fecal and urine incontinence Prognosis • Good • Guarded with cranial mediastinal mass • Guarded to poor • Patients eventually lose function of both hindlimbs and front limbs. • Jack Russell Terrier, Springer Spaniel, Smooth Fox Terrier, Golden Retriever, German Shepard, Labrador Retriever, Dachshund, and Scottish Terrier • German Shepard, Collie, Labrador Retriever, Chesapeake Bay Retriever, Kerry Blue Terrier, and Pembroke Welsh Corgi Notes 6 Table 6.42 / Neurology: Vestibular Disease and Wobbler Syndrome Vestibular Disease of Older Dogs, Acute Wobbler Syndrome (Caudal Cervical Spondylomyelopathy, Cervical Vertebral Instability) Definition Vestibular disease is an acute condition affecting geriatric dogs. It is the disturbance of the peripheral vestibular system. Otitis media is a common cause of the disease in younger dogs. Wobbler syndrome is due to pressure placed on the spinal cord by malformation of bone or spinal ligaments. It leads to instability or chronic disc disease. It is thought that overnutrition and rapid growth may be a contributing factor to this condition. Clinical Signs • Anorexia, asymmetrical ataxia, circling, disorientation, falling, head tilt toward the affected side, loss of balance, nausea, nystagmus, rolling, vomiting • Abnormal gait, ataxia, dragging of toes, knuckling, paraparesis and ambulatory or nonambulatory tetraparesis, rigid flexion of neck, walking difficulty Examination Findings • Facial paresis or paralysis, Horner’s syndrome, strabismus • ↓ Proprioception, pain, supraspinatus atrophy General • Clinical signs • Neurologic examination • Otoscopic examination: fluid, ruptured or bulging tympanum • History/clinical signs Laboratory • N/A • N/A Imaging • Radiographs, skull: osseous bullae fluid, sclerosed, osteitis • MRI/CT: tumor, osseous bullae sclerosed • Radiographs, spine: bony changes, herniation, subluxation or narrowing of intervertebral disc space • Myelogram: site and type of cord compression Procedures • BAER: evaluation of cochlear portion of cranial nerve VIII • CSF analysis: ↑ protein • Thyrotropin stimulation test: minimal to no response Diagnosis Presentation Disease 272 SECTION THREE: DIAGNOSTIC SKILLS Table 6.42 / Neurology: Vestibular Disease and Wobbler Syndrome (Continued) Follow-Up Treatment Disease Vestibular Disease of Older Dogs, Acute Wobbler Syndrome (Caudal Cervical Spondylomyelopathy, Cervical Vertebral Instability) General • Supportive • Fluid therapy • Supportive • Surgery: ventral spondylectomy, dorsal laminectomy, fenestration, stabilization or fusion of involved vertebrae Medication • Antibiotics: trimethoprim-sulfa, cephalexin, cefadroxil, enrofloxacin, orbifloxacin • Antiemetics: dimenhydrinate, meclizine • Tranquilizers: diazepam • Corticosteroids: prednisone, methylprednisone sodium succinate, dexamethasone • Muscle relaxant: methocarbamol, diazepam Nursing Care • Treated as outpatient • • • • Urinary catheter in nonambulatory patients Avoid decubital sores. Physical therapy of all limbs to prevent ankylosis Restrict activity of ambulatory patients or use a neck brace. Patient Care • Restrict activity as needed for disorientation. • Reexam 2–3 days after discharge to verify continued improvement. • Monitor neurologic functions. • Physical therapy Prevention/ Avoidance • Prompt recognition and treatment of ear infections if present • Limit running and jumping. • Use harness instead of a neck collar. Complications • Dehydration • Electrolyte imbalances • Renal insufficiencies • • • • Prognosis • Excellent • Most patients return to normal in 2–3 weeks. • Good when presented ambulatory • Poor when nonambulatory with tetraparesis Notes 6 Failure of surgical repair Degenerative changes of surrounding disc spaces Decubital sores Urinary tract infection or urine scalding • Caution: Flexion and tension stress during radiographs can make clinical signs worse. • Great Dane and Doberman Pinscher ONCOLOGY Table 6.43 / Oncology: Neoplasia Neoplasia Definition Neoplasia is the development of a new and abnormal formation of tissue, as a tumor or growth. It serves no useful function but grows at the expense of the healthy organism. Presentation Disease Clinical Signs • Presence of a tumor or 2 effects attributable to adjacent organ/tissue injury (e.g., halitosis, swelling, pain) • Anorexia, depression, diarrhea, inappetance, lethargy, vomiting, weight loss Examination Findings • Detection of tumor, variable (e.g., lymphadenopathy, organomegaly, hyperemic mucous membranes) and additional disorders CHAPTER 6 / GENERAL MEDICINE 273 Table 6.43 / Oncology: Neoplasia (Continued) Disease • History/clinical signs • Physical examination: tumor and lymph node palpation Laboratory • • • • • • CBC: variable (see specific tumor type), anemia: normocytic and normochromic Chemistry panel: variable (see specific tumor type) Urinalysis: variable (see specific tumor type) Fine needle aspirate, core biopsy, or surgical biopsy of tumor or enlarged lymph node(s) Cytology: cells fulfilling the criteria for malignancy Histopathology: clean margins and tumor grade Imaging • • • • Radiographs, thoracic (VD and left and right laterals): tumor identification, metastases, lymphadenopathy, pleural effusion Radiographs, abdominal: tumor identification, metastases, lymphadenopathy, organomegaly Ultrasound: tumor identification, lymphadenopathy, guided biopsy MRI/CT: tumor identification, metastases, lymphadenopathy, tumor margins, tissue of origin Procedures • Variable General • • • • • • Symptomatic Fluid therapy Radiation therapy Cryosurgery Photodynamic therapy Surgery: excision with 2–3 cm clean margins Medication • • • • Variable (see specific tumor type) Chemotherapy agents Corticosteroids Analgesics Nursing Care • Standard postoperative following surgical excision Patient Care • Variable (see specific tumor type) • Monitor specific blood values • Monitor response to treatment, chemotherapy (see Skill Box 8.13, page 356) appetite, elimination, and energy level Prevention/ Avoidance • N/A Complications • Variable (see specific tumor type) Prognosis • Dependent on tumor type, size, location, time of discovery, and completeness of excision Diagnosis General Follow-Up Treatment 6 274 Neoplasia SECTION THREE: DIAGNOSTIC SKILLS Table 6.44 / Oncology: Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor Disease Histiocytoma (Button Tumor) Mammary Gland Neoplasia Mast Cell Tumor Definition A histiocytoma is a benign skin tumor often found on the head, ear pinna, and limbs. They are most commonly seen in dogs less than 2 years of age. Mammary gland neoplasia is very prevalent among female, intact dogs and very rare in male dogs. The tumors show malignancy 50% of the time. If the tumors are malignant, they have usually metastasized by the time of diagnosis. Mast cell tumors are malignant tumors that arise from mast cells. They are a very unpredictable tumor in their appearance, growth rate, and response to treatment. • Fast growing, firm, small, dome- or button-shaped mass, fast growing, solitary, nonpainful, ± ulcerated • Firm nodular mass, ± ulceration • Nipples: red, swollen, and exudate (e.g., tan, red) • Fever Dogs • Lymphadenopathy, erythema, and edema • Tumor: solitary skin or SQ mass, present for days to months, recent rapid growth Cats • Anorexia and vomiting • Tumor: found in SQ tissue or dermis, papular or nodular, solitary or multiple, hairy or alopecic and/or ulcerated Presentation Clinical Signs Diagnosis Examination Findings • Edematous hindlimbs • Lymphadenopathy, hepatomegaly, intestinal wall thickening, splenomegaly General • Clinical signs • Clinical signs • Mammary gland palpation • History/clinical signs Laboratory • Cytology: pleomorphic round cells, variable sized and shaped nuclei, appearance of hepatocytes, variable amounts of pale blue cytoplasm resembling monocytes, ± lymphocyte, plasma cell, and neutrophil infiltrate • CBC: anemia and leukocytosis • Cytology: cells with cytoplasmic basophilia, variable nuclear/cytoplasmic ratios and if malignant have typical carcinoma clumps (e.g., acinar) • CBC: eosinophilia, basophilia (v), anemia and mastocythemia (rare) • Buffy coat smear: mast cells • Cytology: round cells with basophilic cytoplasmic granules not forming sheets or clumps and ± eosinophilic infiltrate • Biopsy: confirmation and severity of disease • Histopathology: confirmation of completeness of excision Imaging • N/A • Radiographs, thoracic: pleural effusion and lung metastases • Radiographs, abdominal: ascites and ↑ size of sublumbar lymph nodes • Ultrasound: ascites and size of sublumbar lymph nodes • Radiographs, abdominal: ↑ spleen, liver, and lymph nodes • Ultrasound: visceral metastasis Procedures • N/A • N/A • Lymph node aspirates • Darier’s sign: a tumor that has been manipulated will degranulate causing erythema and wheel formations. CHAPTER 6 / GENERAL MEDICINE 275 6 Table 6.44 / Oncology: Histiocytoma, Mammary Gland Neoplasia, and Mast Cell Tumor (Continued) Treatment Disease Histiocytoma (Button Tumor) Mammary Gland Neoplasia Mast Cell Tumor General • Spontaneous regression • Surgery: excision or cryosurgery • Symptomatic • Surgery: mastectomy • • • • • Medication • N/A • Chemotherapy: doxorubicin, cyclophosphamide, and mitoxantrone • Chemotherapy: L-asparaginase, vinblastine, cyclophosphamide, lomustine, and vincristine • Corticosteroids: prednisone • GI protectants: sulcralfate • H1-blockers: diphenhydramine • H2-blockers: cimetidine, ranitidine Nursing Care • Standard postoperative • Standard postoperative • Standard postoperative Patient Care • Monitor its growth and the presence of new tumors. • Reexam every 2 months for reoccurrence of mammary tumors. • Monitor CBC and lymph node enlargement before each chemotherapy administration. • Monitor for the presence of new tumors. Prevention/ Avoidance • N/A • Early hysterectomy: ≤2nd heat cycle • N/A Complications • N/A • • • • • • • • • • Prognosis • Excellent • Dependent on size, time of detection, and completeness of excision • Dependent on the area affected, time of detection, and completeness of excision • Metastasis to regional lymph nodes, liver, spleen, and bone marrow • Boxer, Dachshund, Cocker Spaniel, Great Dane, and Shetland Sheepdog • Freely movable tumor implies benign, and fixed to body wall or skin implies malignant. • Removal of all 4 glands of the affected chain is recommended. • Animals with tumors on the extremities tend to live longer than do animals with trunk tumors. • Boxer, Boston Terrier, Bullmastiff, English Setter, and Siamese cats Follow-Up 6 Notes 276 SECTION THREE: DIAGNOSTIC SKILLS Anemia Ascites DIC Hypercalcemia Osteoporosis Pleural effusion Symptomatic Chemotherapy Radiotherapy Cryosurgery (grade I, small, cutaneous) Surgery: aggressive excision and splenectomy Bleeding Chemotherapy toxicity Hemorrhagic gastroenteritis Radiation reaction Table 6.45 / Oncology: Various Neoplasias Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Complications Prognosis • Dyschezia, tenesmus, PU/PD, pruritis, ulceration, bleeding, weakness, and paresis • Chemistry panel: ↑ calcium, ↓ phosphorus • PTH/PTHrP: ↑ values • Radiographs, thorax: metastasis (nodules) • Radiographs, abdominal: enlarged lymph nodes, fluid • Ultrasound, abdominal: enlarged lymph nodes, liver or spleen nodules • Biopsy: confirmation • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Calcitonin • Diruetics: furosemide • Fluid therapy • Radiation therapy • Surgery: tumor and lymph node excision/debulking • Examination, radiographs, ultrasound and blood work every 3 months following surgery • • • • • • Poor CARCINOMA Adenocarcinoma Anal Sac • Mostly seen in geriatric female dogs with a very high rate of metastasis Fecal incontinence Metastasis Renal failure Reoccurrence Sepsis 6 Nasal • Most tumors begin as unilateral but progress to bilateral • Epistaxis, epiphora, sneezing, nasal discharge, halitosis, and seizures • Facial deformity: nasal bone swelling • Radiographs, skull: tumor location, extent • Radiograph, thorax: metastasis (nodules) • MRI/CT or Rhinoscopy: tumor location, extent and effect on surrounding structures and biopsy • Mycotic cultures: fungal rhinitis • Biopsy: confirmation • Antiemetic: butorphanol • Chemotherapy: cisplatin (canine), cyclophosphamide, piroxicam, vincristine • Radiotherapy • Surgery: tumor excision/debulking • Survey radiographs, CT or MRI when clinical signs return • Brain involvement across cribiform plate • Fair with radiation • Poor with brain involvement Pancreas • Liver metastasis is very common. • Ascites, icterus, maldigestion • Palpable abdominal mass, pyrexia • CBC: mild anemia, neutrophilia • Chemistry panel: ↑ amylase, lipase • Radiograph, abdominal: metastasis, fluid, ascites • Ultrasound, abdominal: tumor, pancreatitis • Biopsy: confirmation • Palliative • Surgery: tumor excision • Monitor quality of life • Diabetes insipidus • Intestinal or biliary obstruction • Pancreatic abscess • Pancreatitis • Peritonitis • Grave CHAPTER 6 / GENERAL MEDICINE 277 Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Complications Prognosis Prostate • Prostrate tumors are always malignant. • Cachexia, constipation, dyschezia, dyspnea, dysuria, exercise intolerance, rear limb lameness, stranguria, tenesmus • Hematuria, pyrexia • CBC: inflammatory leukogram • Chemistry panel: ↑ alk phos, azotemia • Urinalysis: pyuria, ↑ blood, malignant epithelial cells • Radiography, thorax: metastasis • Radiograph, abdominal: lesions, prostrate changes, lymphadenopathy • Ultrasound, abdominal: prostate changes (asymmetry) • Contrast cystography: distortion of prostatic urethra • Analgesics: NSAIDs or opioid drugs • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Stool softeners • Surgery: prostate excision, castration • Monitor ability to urinate and defecate. • Monitor pain levels. • Constipation • Metastasis • Urethral obstruction • Grave Salivary Gland • Dysphagia, pain on opening mouth, swelling of upper neck, ear base, upper lip, maxilla, mucous membrane of lip • Radiographs, thorax: metastasis • Biopsy: confirmation • Radiotherapy • Surgery: tumor excision • Monitor for tumor growth every 3–6 months. Thyroid • High rate of metastasis • Biopsy and FNA can cause excessive bleeding. • Rare in felines • Dysphagia, dysphonia, dyspnea, PU/PD, regurgitation • Firm, nonpainful cervical mass, tachycardia • See Canine Hypothyroidism signs • CBC: nonregenerative anemia • Radiographs, cervical: displacement of normal structures • Ultrasound, thorax: disease extent • CT: disease extent • Radioiodine study: thyroid hormone production • T4, T3, TSH concentrations • Thyroid gland scintigraphy: location • β-Blockers • Analgesics: butorphanol • Chemotherapy: doxorubicin, cisplatin, carboplatin • Methimazole • Radioactive iodine (feline) • Radiotherapy • Surgery: tumor, gland, lymph node excision • Thyroxin (secondary hypothyroidism) • Examination tumor site and radiographs every 3 months • Monitor calcium, thyroid concentration levels. 6 278 SECTION THREE: DIAGNOSTIC SKILLS • Unknown • • • • • • Anemia DIC Hypoparathyroidism Hypothyroidism Laryngeal paralysis Respiratory distress • Dependent on size of tumor and lymph node involvement • Larger fixed tumors have a poor prognosis. Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Complications Prognosis Squamous Cell Carcinoma Digit • Often seen in large, black dogs • Arises from subungual epithelium • Chronic and progressive lameness, swelling, ulceration • Radiographs, affected foot: lysis of the 3rd phalanx • Chemotherapy: cisplatin (canine), mitoxantrone, bovine collagen matrix with 5-fluorouracil • Piroxicam • Retinoids • Surgery: wide margin amputation • Limit sun exposure. • Use sunscreen or tattoo on low pigmented areas of the paws. • Good Ear • Areas of low pigmentation and those subjected to solar radiation are more at risk. • Crusty eczematous lesions on edge of pinna, ulceration • Biopsy: confirmation • Bleomycin • Chemotherapy: cisplatin (intralesional injections) • Cryosurgery • Etretinate • Hyperthermia • Photodynamic therapy • Radiotherapy • Surgery: amputation/ pinnectomy ± ablation of ear canal • Vitamin E • Limit sun exposure. • Use sunscreen or tattoo on low pigmented areas of the ears. • Good with complete excision Gingiva • Bloody oral discharge, dysphagia, excessive salivation, halitosis, loose teeth, and facial deformity • Plaque-like areas that bleed easily • Radiographs, skull: bone involvement and lysis • Radiographs, thorax: metastasis • CT: bone involvement and lysis • Biopsy: confirmation • Chemotherapy: cisplatin (canine), mitoxantrone, carboplatin • Cryosurgery • Photodynamic therapy (PDT) • NSAIDs: piroxicam, ± meloxicam • Radiotherapy • Surgery: tumor excision/debulking • Feed soft foods or by enteral feeding tube. • Poor due to local invasion (feline) • The more rostral the tumor is located, the better is the prognosis (canine). CHAPTER 6 / GENERAL MEDICINE 279 6 Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Skin • Areas of low pigmentation and those subjected to solar radiation are more at risk. • Malignant tumor of squamous epithelium • Crusty, pigmentation, ulceration • Facial skin involvement (feline), nail bed involvement (canine) • Radiographs, extremity: bone involvement • Radiographs, thorax: metastasis • Biopsy: confirmation • Chemotherapy: cisplatin (canine), carboplatin, mitoxantrone, bovine collagen matrix with 5fluorouracil (canine) • Cryosurgery • Photodynamic therapy • Radiotherapy • Retinoids • Surgery: tumor excision/debulking • Reexam and radiographs every 3 months for 1 year, then every 6 months for 1 year. • Limit sun exposure. • Use sunscreen or tattoo low pigmented areas of the skin. • Dysuria, hematuria, pollakiuria, PU/PD, recurrent stranguria, tenesmus, urinary incontinence • Chemistry panel: azotemia if at trigone • Urinalysis: ↑ blood, malignant epithelial cells • Urine culture: UTI • Radiograph, thorax: metastasis • Double contrast cystography: irregularities or mass lesions • IV pyelography, voiding urethrogram or vaginogram • Ultrasound, abdomen: extent of disease, proximity to trigone • Chemotherapy: cisplatin (canine), carboplatin, mitoxantrone • NSAIDs: piroxicam, meloxicam • Radiotherapy • Cystography or ultrasonography every 6–8 weeks • Thoracic radiographs every 2–3 months • Transplantation of cells during surgery or biopsy • Urinary incontinence, urethral or ureteral obstruction, renal failure • Grave • Lameness, nasal discharge • Pain, swelling • Radiograph, affected limb: lesion • Radiograph, thorax: metastasis • CT scan: extent of disease • Nuclear bone scan: staging of disease • Biopsy: definitive diagnosis • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: tumor excision, amputation • Thoracic radiographs monthly for 3 months, then every 3 months • Brain involvement • Poor to excellent, dependent on tumor grade 6 Complications Prognosis • Good with superficial lesions • Guarded with nail bed or digit involvement Transitional Cell Carcinoma Bladder, Urethra • High rate of metastasis • FNA may cause seeding of tumor cells along the needle tract. SARCOMA Chondrosarcoma Bone • Affects large breed dogs 280 SECTION THREE: DIAGNOSTIC SKILLS Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Complications Prognosis Nasal and Paranasal Sinus • Affects large breed dogs • Epiphoria, halitosis, nasal discharge, seizures, sneezing • Facial deformity, pain • Radiographs, skull: tumor, fluid, and destruction of caudal turbinates • MRI/CT: integrity of cribiform plate and orbital invasion • Chemotherapy: doxorubicin • Radiotherapy • Surgery: tumor excision/debulking • Radiographs and CT/MRI may be repeated when clinical signs return. • Fair • Poor with brain involvement (cribriform plate destruction) • Fracture, lameness, pain, swelling • Radiograph, affected limb: lesion • Radiograph, thorax: metastasis • CT: extent of disease • Biopsy: definitive diagnosis • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: tumor excision, amputation • Thoracic radiographs monthly for 3 months, then every 3 months • Guarded • Bloody oral discharge, dysphagia, excessive salivation, halitosis • Facial deformity, loose teeth • Radiographs, skull: bone involvement • Biopsy: intraoral • Chemotherapy: doxorubicin, cisplatin • Cryosurgery • Radiotherapy • Surgery: tumor excision/debulking • Feed soft foods • Fair with early detection and aggressive treatment • Fracture, lameness, pallor, swelling • CBC: regenerative anemia, nucleated RBCs, poikilocytosis, anisocytosis, thrombocytopenia, leukocytosis, ↓ protein • FDP, PT, and PTT: ↑ values • Fibrinogen: ↓ values • Radiographs, bone: lysis • Radiographs, thorax: metastasis • Ultrasound: metastasis • CT: extent of disease • Chemotherapy: doxorubicin, cyclophosphamide • Surgery: tumor excision, amputation • Examination, thoracic radiographs and ultrasound every 3 months for 1 year then every 6 months Fibrosarcoma Bone • Primarily affect the axial skeleton Gingiva 6 Hemangiosarcoma Bone • Pathologic fractures • Rupturing tumors causing hemorrhage • Unknown CHAPTER 6 / GENERAL MEDICINE 281 Table 6.45 / Oncology: Various Neoplasias (Continued) 6 Type of Cancer Clinical Signs Diagnosis Treatment Follow-Up Complications Prognosis Heart • Pulmonary metastasis very common • Dyspnea, exercise intolerance, syncope, weight loss • Abdominal and pleural effusion, arrhythmia, hepatomegaly, hindlimb paresis, jugular distention, pulse deficits • CBC: anemia, nucleated RBCs • Chemistry panel: azotemia • Ultrasound, thorax: location of tumor • Biopsy, heart: definitive diagnosis • Chemotherapy: doxorubicin, vincristine, cyclophosphamide • Pericardial and pleuralcentesis • Surgery: tumor excision/debulking • Examination, thoracic radiographs and ultrasound monthly • Centesis, surgery complications • Guarded to poor Spleen, Liver • Rapid growth and widespread metastatic vascular neoplasia • Ataxia, dementia, intermittent collapse, lameness, paresis, seizures, weakness • Enlarged abdomen, pale mucous membranes, peritoneal fluid, tachycardia • CBC: regenerative anemia, polychromasia, reticulocytosis, nucleated RBCs, anisocytosis, leukocytosis, neutrophilia, thrombocytopenia • Chemistry panel: ↑ liver enzymes • FDP, PT, and PTT: ↑ values • Radiograph, abdomen: tumor detection, fluid • Radiograph, thorax: metastasis • Ultrasound, heart: tumor location and metastasis • Antihistamines: diphenhydramine • Biological response modifier L-MTP-PE • Blood transfusions • Chemotherapy: cyclophosphamide, doxorubicin, chlorambucil, methotrexate, vincristine • Fluid therapy • Surgery: splenectomy • Restrict activity • Thoracic and abdominal radiographs and abdominal ultrasound every 3 months • Sepsis • Skin sloughs • Tumor rupture leading to hemorrhage • Vomiting and diarrhea • Poor • CBC: anemia, leukocytosis, and lymphoblastosis • Chemistry panel: ↑ creatinine, BUN, ALT, AST, calcium • Urinalysis: ↑ bilirubin, protein, isothenuria • Serology: + FeLV • Cobalamin and folate: ↓ values • Ultrasound, abdominal • Cytology: bone marrow, tumor, lymph nodes • Histopathology: clean margins and tumor grade • Chemotherapy: vincristine, cytosine arabinoside, methotrexate, cyclophosphamide, chlorambucil, L-asparaginase, doxorubicin, actinomycin-D • Corticosteroids: prednisone • Surgery • Examination, CBC and platelet count before each weekly cycle of chemotherapy • Leukopenia • Sepsis • Dependent on form Lymphosarcoma/Lymphoma Feline • Most common sites are alimentary tract, anterior mediastinum, liver, spleen, and kidneys. 282 • Dependent on form (mediastinal, renal, alimentary, solitary or multicentric) • Coughing, open mouth breathing, regurgitation, weight loss • Renal failure signs, thickened intestines SECTION THREE: DIAGNOSTIC SKILLS Table 6.45 / Oncology: Various Neoplasias (Continued) Type of Cancer Clinical Signs • Canine • Seen most commonly is solid tissues: lymph nodes, bone • marrow and visceral organs • ↑ Risk with exposure to the herbicide: 2,4dichlorophenoxyacetic Coughing, drooling, dysphagia, dyspnea, exercise intolerance Anterior uveitis, ascites, lymphadenopathy, lymphoid infiltrate, organomegaly Diagnosis Treatment Follow-Up Complications Prognosis • CBC: anemia, lymphocytosis, lymphopenia, neutrophilia, monocytosis, circulating blasts, and thrombocytopenia • Chemistry panel: ↑ ALT, ALP, and calcium • Echo: cardiac contractility • Ultrasound, abdominal • Cytology: bone marrow, tumor, lymph nodes • Histopathology: clean margins and tumor grade • Immunochemical staining of lympocytes • Chemotherapy: doxorubicin, vincristine, epirubicin, cyclophosphamide, L-asparaginase, methotrexate, chlorambucil • Corticosteroids: prednisone • Fluid therapy • Radiotherapy • Retinoids • Surgery • Thoraco- and abdominocentesis • Restrict activity of patients with ↓ WBCs or platelet count. • Monitor CBC and platelet count during chemotherapy. • Echo and ECG: cardiotoxicity of doxorubicin • Alopecia • DIC • Leukopenia and neutropenia • Pancreatitis • Sepsis • Tissue sloughing • Vomiting and diarrhea • Good 6 Osteosarcoma • Most common bone tumor in dogs, typically affecting the appendicular skeleton of large to giant breeds • Lameness, pain, swelling • Pathologic long bone fracture • Radiograph, affected bone: bone lysis, proliferation in the metaphyseal region of long bones, soft tissue swelling • Nuclear bone scans: bony or soft tissue metastatic disease • Analgesics: butorphanol, piroxicam, fentanyl, morphine sulfate • Biological response modifiers: L-MTP-PE • Chemotherapy: cisplatin (canine), carboplatin, doxorubicin • Radiotherapy • Surgery: amputation • Restrict activity. • Monitor radiographs every 2–3 months. • Monitor CBC and platelet count 7–10 days after chemotherapy. • Metastasis (>90% of cases at examination) and hypertrophic osteopathy • Guarded once metastases is present Vaccine-Induced Sarcoma • Typically fibrosarcoma, but may be many other types of sarcoma •Most common with FeLV and rabies • Firm, painless, SQ swelling located at a previous vaccination site • Radiograph, tumor site: bone lysis or extension of the tumor along other tissue planes • Radiograph, thorax: metastasis check • Contrast CT scan: extent of disease • Biopsy: confirm diagnosis • Histopathology: clean margins and tumor grade • Chemotherapy: doxorubicin, cyclophosphamide • Radiotherapy • Surgery • Evaluate monthly for 3 months, then every 3 months. • Monitor CBC and platelet count before each chemotherapy treatment. • Recurrence, new lesions • Poor CHAPTER 6 / GENERAL MEDICINE 283 OPHTHALMOLOGY Table 6.46 / Ophthalmology: Anterior Uveitis and Cataracts Disease Presentation Definition Treatment Diagnosis 6 284 Anterior Uveitis Cataracts Anterior uveitis is inflammation of the iris and ciliary body. Corneal ulceration, trauma, autoimmune, lens-induced, or infections can cause anterior uveitis, but the disease may also be primary. Cataracts are pathological changes in the eye that lead to opacity. The changes are in the lens protein composition or disruption of lens fiber arrangement. The general causes are hereditary, inflammatory, metabolic, traumatic, nutritional, or toxic. Clinical Signs • Blepharospasm, blindness, elevation of nictitating membrane, epiphora, inappetence, lethargy, miosis, photophobia, redness, tearing • Blindness, visual impairment Examination Findings • Aqueous flare, conjunctival hyperemia, hypotony, corneal edema, fibrinous exudate • Aqueous flare, any opacity in the lens of a dilated eye, synechia General • Clinical signs • Ophthalmic examination • History/clinical signs • Ophthalmic examination Laboratory • Chemistry panel: ↑ globulin • Serology: toxoplasmosis, Bartonella, FeLV, FIP, FIV, FHV-1 • Serology: systemic mycoses, rickettsial disease, brucellosis, toxoplasmosis, FeLV, FIV Imaging • Radiographs, thoracic: tumors or evidence of fungal disease • Radiographs, abdominal: tumors • Ultrasound, ocular: foreign body and penetrating wounds • Ultrasound, ocular: retinal detachment Procedures • Tonometry: ↓ pressure or ↑ pressure when secondary to glaucoma • • • • General • Symptomatic • Supportive • Surgery: phacoemulsification, extracapsular extraction, and implantation of an intraocular lens • Laser surgery: capsulotomy Medication • Antibiotics: clindamycin • Corticosteroids (systemic): prednisone • Corticosteroids (topical): 1% prednisolone acetate, 0.1% dexamethasone • Mydriatic-cycloplegic: 0.5–1% atropine • NSAIDs: 0.03% flurbiprofen, 1% suprofen, Rimadyl, Deramaxx, meloxicam • • • • Nursing Care • Treated as outpatient • Treated as outpatient • Standard postoperative (e.g., monitor in flammation) • Pain management SECTION THREE: DIAGNOSTIC SKILLS Electroretinogram: degree of retinal atrophy Gonioscopy Biomicroscopy Tonometry: ↓ pressure Corticosteroids: 1% prednisolone acetate Mydriatics: 1% tropicamide NSAIDs Mydriatic-cycloplegic: atropine Table 6.46 / Ophthalmology: Anterior Uveitis and Cataracts (Continued) Follow-Up Disease Anterior Uveitis Cataracts Patient Care • Reexam 5–7 days after initiation of treatment then every 2–3 weeks • Monitor intraocular pressure • Examination frequently for several months postoperative, then every 6 months for life Prevention/ Avoidance • N/A • Prompt treatment of uveitis • Selective breeding • Well-balanced nutrition in hand-fed neonates Complications • • • • • • • • • • Prognosis • Dependent on severity of disease upon presentation • Dependent on stage and location of disease and age of animal • Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration. • It takes 2 months for the blood-aqueous barrier to completely heal after an insult; therefore, continue to treat for 2 months. • Caution: Differentiate from nuclear sclerosis, which is an increase in the clarity of the nucleus of the lens and is a normal aging process. • Special considerations must be taken with medications and procedures for patients with diabetes mellitus. • Miniature Poodle, American Cocker Spaniel, Miniature Schnauzer, Golden Retriever, Boston Terrier, and Siberian Husky and Persian, Birman, and Himalayan cats Notes Blindness Secondary glaucoma Cataracts Endophthalmitis or panophthalmitis Iris atrophy Lens luxation Anterior uveitis Corneal endothelial damage Glaucoma Retinal detachment 6 Table 6.47 / Ophthalmology: Conjunctivitis and Entropion Disease Entropion Conjunctivitis is a general term for inflammation of the ocular mucous membrane that covers the sclera and lines the inner surface of the eyelids. Its causes can be infectious, foreign body, trauma, tear film deficiency, chemical or environmental irritants, immune-mediated, or due to other eye diseases. Entropion is the inward rolling of the eyelid, causing contact of the eyelashes or eyelid hair with the eye. Clinical Signs • Discharge, pain • Blepharospasms, blindness, epiphora, purulent discharge, visual impairment Examination Findings • Chemosis, hyperemia, tissue proliferation • Conjunctivitis, corneal rupture, corneal ulceration Definition Presentation Conjunctivitis CHAPTER 6 / GENERAL MEDICINE 285 Table 6.47 / Ophthalmology: Conjunctivitis and Entropion (Continued) Diagnosis Disease • History/clinical signs • Ophthalmic examination • History/clinical signs • Ophthalmic examination Laboratory • Serology: FeLV or FIV • Cytology: inflammation, neoplasia, viral or chlamydial infection • Biopsy: neoplasia or preocular mucin deficiency • N/A Imaging • N/A • N/A Procedures • • • • General • Symptomatic • Surgery: keratectomy or removal of foreign body, hairs or mass • Surgery: correction of anatomic entropion, eyelid eversion suture technique Medication • Amino acid: L-lysine (FHV-1) • Antibiotics (systemic): tetracycline, erthyomycin, chloramphenical • Antibiotics (topical): triple antibiotic, oxytetracycline, erythromycin, doxycycline • Antiviral: trifluridine, vidarabine, interferon • Corticosteroids (systemic): megesterol acetate • Corticosteroids (topical): 1% dexamethasone • Lacrimostimulants: hyaluronic acid • NSAIDs • Antibiotic (topical): triple antibiotic Nursing Care • Irrigate the eye with a eyewash solution to remove any exudate. • Clip the hair surrounding the eye. • Apply an Elizabethan collar to prevent self-trauma. • Treated as outpatient. Patient Care • Maintain the eyes clear of exudate. • Examination 5–7 days after initiation of treatment and then as needed • Do not allow rubbing at eyes/sutures. Prevention/ Avoidance • Vaccinate. • Isolate patients with infectious conjunctivitis. • Minimize stress for patients with the herpetic conjunctivitis. • Selective breeding Complications • Corneal sequestration • Symblepharon • Keratoconjunctivitis sicca (KCS) • Conjunctivitis • Impaired vision Prognosis • Excellent with bacterial conjunctivitis • Fair with feline herpesvirus, immune-mediated diseases, or KCS • Good • Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration. • Chow, Shar pei, and hunting dogs Follow-Up Notes 286 Entropion General Treatment 6 Conjunctivitis Schirmer tear test: ↓ tear production Fluorescein stain: ulceration and nasolacrimal duct patency Culture: bacteria or fungi isolation and identification Tonometry: ↑ pressure SECTION THREE: DIAGNOSTIC SKILLS • N/A Table 6.48 / Ophthalmology: Cilia Disorders and Glaucoma Disease Presentation Diagnosis Treatment Glaucoma Cilia disorders are the abnormal location or positioning of the eyelashes. Trichiasis is cilia arising from normal sites that are directed toward the eye. Distichiasis is the growing of cilia from the meibomian glands and emergence from their ducts. Ectopic cilia are cilia that arise from the meibomian gland and erupt through the palpebral conjunctival surface. Glaucoma is an increase in intraocular pressure with subsequent damage to the optic nerve. Chronic glaucoma is often caused by retinal and optic nerve degeneration and buphthalmos. Clinical Signs • Blepharospasm, discharge, epiphora • Blepharospasm, blindness, dilated pupil, epiphora, impaired vision, ↑ pupillary light response • Weak to absent menace response Examination Findings • Anisocoria, hyperemia, chemosis, pain, pigmentation, tissue proliferation, vascularization • Buphthalmos, conjunctival hyperemia, corneal edema, luxated lens, retinal degeneration General • History/clinical signs • Ophthalmic examination • History/clinical signs • Ophthalmic examination Imaging • N/A • Radiographs, skull: fungi or neoplastic lesions • Ultrasound, ocular: structural abnormalities Procedures • N/A • Tonometry: ↑ pressure, >25–30 mm Hg (canine) and >31 mm Hg (feline) • Electroretinography: vision loss General • Surgery: cryoepilation, electroepilation, tarsoconjunctival resection, facial fold resection, or medial canthal closure • Supportive • Symptomatic • Surgery: cyclophotocoagulation, gonioimplatation, intraocular prosthesis or enucleation Medication • Antibiotics (topical): triple antibiotic • Adrenergic agents: 0.1% dipivefrin, 0.25–0.5% timolol • Miotics: pilocarpine 2%, demecarium bromide, epinephrine 1%, dipivefrin HCl 0.1%, or timolol maleate 0.5% • Carbonic anhydrase inhibitors: methazolamide, dorzolamide, brinzolamide • Corticosteroids: dexamethasone • Diuretics: 20% mannitol or glycerin • Prostaglandins: latanoprost Nursing Care • Treated as outpatient • Treated as outpatient Patient Care • Treat swelling with topical antibiotics, corticosteroids, and/or hypertonic saline. • Warm, moist compresses twice daily for 5–7 days postoperative • Monitor every 1–2 days for 1 week for improvement. • Treat the other eye prophylactically daily with an autonomic agent. Definition Follow-Up Cilia Disorders (Distichiasis, Trichiasis and Ectopic Cilia) 6 Laboratory CHAPTER 6 / GENERAL MEDICINE 287 Table 6.48 / Ophthalmology: Cilia Disorders and Glaucoma (Continued) Follow-Up Disease Cilia Disorders (Distichiasis, Trichiasis and Ectopic Cilia) Glaucoma Prevention/ Avoidance • Clip hair on facial folds and around the eyes. • Yearly ophthalmic examination in predisposed breeds • Examinations 2–3 times a year on unaffected eye when 1 eye already has glaucoma Complications • Recurrence • Conjunctivitis • Keratitis • Blindness • Chronic ocular pain Prognosis • Excellent with facial fold resection • Fair to good with hair removal • Fair with surgery • Poor with medical treatment alone • Felines do not have cilia, and canines normally only have them on the upper eyelid. • Normal intraocular pressure is 15–25 mm Hg. • 50% of animals develop glaucoma in the second eye within 8 months of the initial diagnosis. • 40% of dogs will be blind in affected eye within 1 year regardless of treatment. • May take up to 6 weeks for vision to return Notes 6 Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca Disease Presentation Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome) Nonulcerative (Chronic Superficial Keratitis) Ulcerative (Corneal Ulceration/Erosion) Keratitis is inflammation of the cornea with possible corneal erosion. It can be caused by trauma, foreign bodies, bacterial infection, irritant, cilia disorders, KCS, feline herpesvirus, or corneal exposure. Ulceration is the loss of a full-thickness of epithelium with at least some stromal loss. This can be caused by trauma, bacterial infection, pseudomonas, feline herpesvirus, epithelial dystrophy, corneal dryness, neurotrophic keratitis, or complications from other diseases. KCS is a lack of normal tear production causing drying and inflammation of the cornea and conjunctiva. It is thought to be an immune-mediated disease against the lacrimal gland. It can also be caused by long-term use of sulfonamides. Clinical Signs • Blepharospasm, photophobia, prolapsed third eyelid, squinting, rubbing at eyes, serous to mucopurulent discharge, tearing • Blepharospasm, epiphora, photophobia, rubbing at eyes, serous to mucopurulent discharge • Blepharospasms, blindness, eye rubbing, mucoid to mucopurulent discharge, periocular crust, photophobia, pruritus Examination Findings • Corneal edema, hyperemia, neovascularization, pigmentation • Aqueous flare, corneal edema, corneal opacity, conjunctival hyperemia, hypotony, miosis, neovascularization, surface depression • Chemosis, dull, opaque or pigmentation of cornea, hyperemia, superficial vascularization, thickened conjunctiva, ulceration Definition 288 Keratitis SECTION THREE: DIAGNOSTIC SKILLS Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca (Continued) Follow-Up Treatment Diagnosis Disease Keratitis Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome) Nonulcerative (Chronic Superficial Keratitis) Ulcerative (Corneal Ulceration/Erosion) General • History/clinical signs • Ophthalmic examination • History/clinical signs • Ophthalmic examination • History/clinical signs • Ophthalmic examination Laboratory • Virus isolation: feline herpesvirus • Virus isolation: feline herpesvirus • Culture: bacteria or fungi isolation and identification • Cytology: severity of bacterial overgrowth Imaging • N/A • N/A • N/A Procedures • Schirmer tear test: ↓ production • Cytology: recognition and identification of bacteria • Fluorescein stain: retention of stain • Schirmer tear test: >15 mm/min • Schirmer tear test: ↓ production, <10 mm/min • Fluorescein stain: retention of stain General • Symptomatic • Contact lenses • Plesiotherapy with strontium-90–generated beta-radiation • Surgery: debridement, laceration repair, keratotomy, keratectomy, superficial keratotomy, or conjunctival flap surgery • Symptomatic • Debridement of ulcer edges • Surgery: conjunctival flap, tissue adhesion, pedicle flap, keratectomy, linear keratotomy, contact lenses and collagen shields • Symptomatic • Surgery: transposition of the parotid salivary duct Medication • 2% Cyclosporine • Antibiotics: chloramphenical, tobramycin, erythromycin, triple antibiotic or gentamicin • Antiviral: trifluridine or idoxuridine • Mydriatic-cycloplegic: atropine • Corticosteroids (topical): 0.1% dexamethasone, 1% prednisolone acetate • Mucolytics: acetylcysteine • NSAIDs: aspirin • Antibiotics (systemic): variable • Antibiotics (topical): gentamicin, tobramycin and triple antibiotic • Antiprotease agent: acetylcysteine • Antibiotics (topical): variable • Artificial tears supplementation: hyaluronic acid, hydroxypropyl methycellulose • Immunosuppression: cyclosporine, tacrolimus • Miotics: pilocarpine • Mucolytics: acetylcysteine Nursing Care • Treated as outpatient • With deep ulcer, restrict activity to prevent rupture. • Apply an Elizabethan collar to prevent self-trauma. • Clean eyes regularly to keep them clear of discharge. Patient Care • Exam every 1–2 weeks to monitor progress until resolved. • Monitor healing process with fluorescein stain every 1–2 days until improvement is seen. • Monitor Schirmer tear test every 2–4 weeks until normal. • Clean eyes regularly to keep them clear of discharge. Prevention/ Avoidance • N/A • Lubricant ointment administration in brachycephalic (canine) • Continuous treatment with KCS • N/A CHAPTER 6 / GENERAL MEDICINE 6 289 Table 6.49 / Ophthalmology: Keratitis and Keratoconjunctivitis Sicca (Continued) Disease Keratoconjunctivitis Sicca (KCS, Dry Eye Syndrome) Ulcerative (Corneal Ulceration/Erosion) Complications • Blindness • KCS • Keratitis, ulcerative • • • • • • • Prognosis • Dependent on severity of disease may require lifelong treatment • Fair to good: may take several weeks to heal • Good with lifelong treatment • Caution: Corticosteroids are contraindicated in cases of primary conjunctivitis and corneal ulceration. • Schirmer tear test: at least 15 mm/min of wetting • Acetylcysteine 5% is mixed 1 : 1 with artificial tears for ophthalmic use. • Cocker Spaniel, Bulldog, West Highland Terrier, Lhaso Apso, Miniature Schnauzer, and Shih tzu Follow-Up Nonulcerative (Chronic Superficial Keratitis) Notes • Keratitis, ulcerative Descemetocele Chronic ophthalmitis Glaucoma Rupture of globe Endophthalmitis Blindness Phthisis bulbi Table 6.50 / Ophthalmology: Lens Luxation and Prolapsed Gland of the Third Eyelid Lens Luxation Prolapsed Gland of the Third Eyelid (Cherry Eye) Definition Lens luxation is the actual movement of the lens either anteriorly or posteriorly. It is often caused by glaucoma, uveitis, cataracts, trauma, or primary zonular degeneration. Cherry eye is caused by a weak attachment to the nictitating membrane gland, allowing it to protrude/prolapse from the leading edge of the third eyelid. Clinical Signs • Blepharospasm, epiphora, redness • Blepharospasms, discharge, epiphora, swelling at medial canthus Examination Findings • Aphakic crescent, corneal edema, hyperemia, iridodenesis, pain • Conjunctivitis, hyperemia General • Clinical signs • Ophthalmic examination • History/clinical signs • Clinical Signs Laboratory • N/A • N/A Imaging • Radiographs, thoracic: metastasis from intraocular neoplasia • Ultrasound, ocular: structural abnormalities • N/A Procedures • Wood’s lamp: fluorescence of a clear lens • Tonometry: ↑ values • N/A Presentation Disease Diagnosis 6 Keratitis 290 SECTION THREE: DIAGNOSTIC SKILLS Table 6.50 / Ophthalmology: Lens Luxation and Prolapsed Gland of the Third Eyelid (Continued) Follow-Up Treatment Disease Lens Luxation Prolapsed Gland of the Third Eyelid (Cherry Eye) General • Supportive (posterior luxation) • Surgery (anterior luxation): cyclocryosurgery, evisceration, intrascleral prosthesis or enucleation • Surgery: repositioning of the nictitating membrane gland and anchoring securely Medication • • • • Mydriatics: 1% tropicamide Miotics: demecarium bromide Carbonic anhydrase inhibitors: dichlorphenamide Corticosteroids (topical): 0.1% dexamethasone, prednisolone acetate • Diuretics: mannitol • Antibiotics: variable • Corticosteroids (topical): 1% dexamethasone • NSAIDs Nursing Care • Treated as outpatient • Standard postoperative Patient Care • Examine within 24 hours and then frequently after that until intraocular pressure stabilizes. • Examine every 3 months. • Do not allow rubbing at eyes/sutures. Prevention/Avoidance • Selective breeding • Selective breeding Complications • • • • • • • • • Reprolapse of the gland • Infection at surgery site • Corneal ulcer/erosion secondary to suture abrasion Prognosis • Good with surgery • Excellent with surgery • Caution: Pupil should not be dilated with acute anterior lens luxation. • Poodle, Shar pei, Whippet, Norwegian Elkhound, and terriers • Cocker Spaniel, Bulldog, Pitbull Terrier, Beagle, Bloodhound, Lhasa Apso, Shih tzu, and Shar pei Notes Uveitis Corneal edema Dyscoria Blindness Synechia Glaucoma Retinal detachment Vitreous entrapment in the incision CHAPTER 6 / GENERAL MEDICINE 6 291 UROLOGY Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS) Pyelonephritis (Upper Urinary Tract Infection) Definition Any macroscopic concretions found within the urinary bladder are called cystic calculi. They can be found anywhere along the urinary tract, but most commonly seen in the urinary bladder. FLUTD is inflammation of the lower urinary tract including the bladder and urethra. It is typically idiopathic. It can also occur secondary to bacterial infection, crystalluria, or iatrogenic (e.g., urinary catheterization). Pyelonephritis is inflammation of the renal parenchyma, collecting diverticula, ureters, and its pelves. It is typically used to refer to a kidney infection and is most commonly secondary to bacterial invasion. Clinical Signs • Dysuria, hematuria, malodorous, stranguria, pollakiuria • Anuria, dysuria, hematuria, licking at perineal area, periuria, pollakiuria, polyuria • Anorexia, arched back, cachexia, depression, dysuria, hematuria, lethargy, malodorous or discolored urine, pollakiuria, PU/PD, stranguria, vomiting Examination Findings • Abdominal pain, dehydration • Thickened, firm contracted bladder wall • Abdominal and lumbar pain, dehydration, pyrexia, tachycardia General • History/clinical signs: recurrent bacterial UTIs • Bladder palpation (v) • History/clinical signs • Abdominal palpation: bladder • Perineal examination • History/clinical signs • Abdominal palpation: kidney Laboratory • Chemistry panel: ↑ potassium, BUN, creatinine and metabolic acidosis • Urinalysis: ↑ bacteria, crystals, change in pH (depending on type of crystal) • Urine culture: bacteria isolation and identification • Bile acids or ammonia concentration: ↑ with ammonium urate calculi and portosystemic shunts • Stone analysis and bacterial culture: needed for long term treatment • Urinalysis: pyuria, ↑ blood, bacteria, crystals • Urine culture: bacteria isolation and identification • CBC: neutrophilic leukocytosis with a left shift (v) and nonregenerative anemia • Chemistry panel: ↑ BUN, creatinine, phosphorus and azotemia • Urinalysis: pyuria, ↑ bacteria, blood, protein, leukocyte casts, crystals, ↓ specific gravity • Urine culture: bacteria isolation and identification • Cytology, renal pelvis: bacteria and neutrophils Imaging • Radiographs, abdominal: radiopaque calculi • Contrast: radiolucent calculi and vesicourachal diverticula • Ultrasound, abdominal: calculi • Radiographs, abdominal: anatomic abnormalities, calculi, urethral plugs, tumors, or urachal diverticula • Contrast: urethral strictures, tumors, radiolucent uroliths, or vesicourachal diverticula • Ultrasound, abdominal: anatomic abnormalities, calculi, tumors, or urachal diverticula • Radiographs, abdominal: ↓ size of kidneys and contours (v) • Ultrasound, abdominal: dilation of renal pelves and proximal ureter, kidney size, and nephrolithiasis Procedures • N/A • N/A • Pyelocentesis Presentation Cystic Calculi (Urocystoliths) Diagnosis 6 Disease 292 SECTION THREE: DIAGNOSTIC SKILLS Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis (Continued) Cystic Calculi (Urocystoliths) Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS) Pyelonephritis (Upper Urinary Tract Infection) General • • • • Symptomatic Medical dissolution (struvite only) Urohydropulsion Surgery • Symptomatic • Symptomatic • Surgery: nephrotomy • Lithotripsy Medication • • • • Allopurinol (ammonium urate) Antibiotics: variable MPG or D-penicillamine (cystine) Urine alkalinizer: potassium citrate • • • • • Antibiotics: variable Follow-Up Treatment Disease • • • • • Analgesics: butorphanol, buprenorphine Antibiotics: variable Anticholinergics: propantheline Glycosaminoglycan: glucosamine, pentosan polysulfate sodium Methenamine mandelate Phenoxybenzamine Tranquilizers: diazepam Tricyclic antidepressant: amitriptyline Urine acidifier: DL-methionine, ammonium chloride 6 Nursing Care • Access to clean litter box or frequent walks • Monitor for anuria. • Access to clean litter box or frequent walks • Monitor for anuria. • Treated as outpatient • Access to clean litter box or frequent walks • Treated as outpatient Patient Care • Monitor urine pH and specific gravity. • Strict diet restrictions depending on type of calculus • Monitor dissolution monthly by radiographs, urinalysis, urine culture, and ultrasonography. • Monitor radiographs every 3–4 months on patients with surgical removal for reoccurrence. • Culture urine 1 week after beginning treatment. • ↑ Water consumption by feeding canned food mixed with water, adding potassium or sodium chloride to the food or subcutaneous fluids. • Monitor males for urethral obstruction. • Culture urine 3–5 days and 1 month after beginning treatment. • Perform a urinalysis and urine culture 7 days and 28 days after completing treatment. • ↑ Water consumption by feeding canned food mixed with water, adding sodium chloride to the food or subcutaneous fluids Prevention/ Avoidance • Strict diet restrictions depending on type of calculi • Monitor urine pH. • • • • • Correct ectopic ureters. • Encourage water consumption. Complications • Reoccurrence • Urethral obstruction • Secondary bacterial UTI • Urethral obstruction (feline, male) • Recurrence • • • • • Prognosis • Excellent with treatment • Excellent • Fair to good: may have irreversible kidney damage Acidifying or low magnesium diet Avoid stress. Encourage water consumption. Maintain a clean litter box. Chronic renal failure Reoccurrence Nephrolithiasis Septicemia or septic shock Metastatic infection CHAPTER 6 / GENERAL MEDICINE 293 Table 6.51 / Urology: Cystic Calculi, Feline Lower Urinary Tract Disease, and Pyelonephritis (Continued) Cystic Calculi (Urocystoliths) Notes • Calculi and urine pH • Struvite: alkaline urine • Ammonium urate and silica : neutral to acid urine • Cystine: acid urine • Calcium oxalate: any urine pH Feline Lower Urinary Tract Disease (FLUTD) (Feline Urologic Syndrome, FUS) Pyelonephritis (Upper Urinary Tract Infection) Table 6.52 / Urology: Renal Failure Disease Presentation 294 Renal Failure Acute (ARF) Chronic (CRF) Acute renal failure is the rapid decline in renal function. It is the accumulation of uremic toxins due to filtration failure, dysregulation of fluids, electrolytes, and acid-base balances. Unlike CRF, this condition may be reversible if diagnosed quickly and treated aggressively. Chronic renal failure is the progressive decline in the function of the kidneys leading to their shutdown over months to years. The damage is irreversible. The causes may be familial, toxins, infections, neoplasia, or infectious disease. Clinical Signs • Anorexia, anuria, ataxia, bruising, diarrhea, dyspnea, lethargy, depression, oliguria, polyuria, seizures, tachypnea, vomiting • Anorexia, blindness, coma, constipation, diarrhea, lethargy, nocturia, PU/PD, seizures, vomiting, dehydration weakness, and exercise intolerance Examination Findings • Bradycardia, cardiac abnormalities, dehydration, enlarged painful kidneys, halitosis, hypothermia, nonpalpable urinary bladder, oral ulcerations, pyrexia • Ascites, dehydration, halitosis, oral ulcerations, small, firm nodular kidneys, subcutaneous edema General • History/clinical signs • Abdominal palpation: kidney • History/clinical signs • Abdominal palpation: kidney Laboratory • CBC: leukocytosis with or without a left shift (v), lymphopenia, monocytosis, ↑ PCV and nonregenerative anemia (v) • Chemistry panel: ↑ BUN, creatinine, phosphate, glucose, potassium, alk phos, albumin, lipase, calcium (ARF), ↓ protein, calcium (ethylene glycol) and azotemia • Urinalysis: pyuria, bacteria, crystals, ↑ albumin, glucose, cellular and granular casts, ↓ specific gravity • Protein-to-creatinine ratio: >1 (3–5 severe) • Urine culture: bacteria isolation and identification • Blood gasses: metabolic acidosis • Serology: leptospirosis or ehrlichiosis • Eythlene glycol concentration: + results • Biopsy: confirmation, cause and severity of disease • CBC: nonregenerative anemia • Chemistry panel: ↑ protein, BUN, creatinine, amylase, lipase, phosphate, ↓ potassium, ± calcium and metabolic acidosis • Urinalysis: ↑ protein (v), ↓ specific gravity • Protein:creatinine ratio: to determine severity of proteinuria and glomerular disease • Culture, urine: bacteria isolation and identification • Biopsy, renal: confirmation, cause and severity of disease Definition Diagnosis 6 Disease SECTION THREE: DIAGNOSTIC SKILLS Table 6.52 / Urology: Renal Failure (Continued) Disease Chronic (CRF) Imaging • Radiographs, abdominal: renal size and shape, renal uroliths, peritonitis • Contrast: obstruction or structural rupture • Ultrasound, abdominal: renal uroliths and parenchymal and anatomical abnormalities • Radiographs, abdominal: renal size and shape and renal uroliths • Contrast: obstruction or structural rupture Procedures • Endoscopy: gastric ulcers • Blood pressure: hypertension • Blood pressure: hypertension General • • • • • • • • • • • • • • • Diagnosis Acute (ARF) Symptomatic Supportive Fluid therapy, ± potassium Hemodialysis Peritoneal dialysis Blood transfusions Poison antidotes (e.g., ethylene glycol) Renal transplantation Medication • • • • • • • • Nursing Care • • • • Patient Care • Monitor blood values until normal. • Nutritional support • Renal diet: ↑ omega-3, omega-6, caloric density, fiber, ↓ highquality protein, phosphorus, sodium • Fresh water at all times to increase water consumption • Subcutaneous fluids for diuresis and hydration Treatment Follow-Up Renal Failure Alkalinizer: sodium bicarbonate Anabolics: testosterone, nandrolone, oxymethalone, stanozolol Antibiotics: variable Antiemetics: trimethobenzamide or chlorpromazine Calcium gluconate Diuretics: 20% mannitol, 20% dextrose, furosemide H2-receptor antagonist: cimetidine or rantidine Phosphate binders: aluminum hydroxide, calcium carbonate, calcium acetate, epakitin • Potassium supplement: potassium chloride, potassium gluconate • Vasodilators: dopamine Symptomatic Supportive Fluid therapy Hemodialysis Peritoneal dialysis Blood transfusions Renal transplantation 6 • • • • • • ACE inhibitors: enalapril, benazepril, amlodipine Alkalinizer: sodium bicarbonate Androgens: stanozolol, nandrolone decanoate Erythropoietin: rHuEPO H2-receptor antagonist: cimetidine, famotidine, rantidine Phosphate binders: aluminum hydroxide, calcium carbonate, calcium acetate, epakitin • Potassium supplement: potassium chloride, potassium gluconate • Vitamin D: calcitriol Nutritional support Monitor urine output, 1–3 mL/min initially. Monitor hydration, temperature, and body weight. Monitor PCV and blood values. • Nutritional support • Renal diet: ↑ omega-3, omega-6, caloric density, fiber, ↓ high quality protein, phosphorus, sodium • Fresh water at all times to increase water consumption • Subcutaneous fluids for diuresis and hydration • Monitor weekly initially, then monitor hydration; weight and blood values every 1–4 months depending on severity of CRF CHAPTER 6 / GENERAL MEDICINE 295 Table 6.52 / Urology: Renal Failure (Continued) Follow-Up Disease Renal Failure Acute (ARF) Chronic (CRF) Prevention/ Avoidance • Anticipate ARF in susceptible animals and conduct preventative fluids and medication. • Avoid use of nephrotoxic drugs. • Restrict exposure to antifreeze. • Maintain adequate blood pressure during anesthesia, especially in prolonged procedures and older animals. • Anticipate ARF in susceptible animals and conduct preventative fluids and medication. • Avoid use of nephrotoxic drugs. • Maintain adequate blood pressure during anesthesia. • Selective breeding Complications • Cardiac arrhythmias, congestive heart failure, pulmonary edema, uremic pneumonitis, or cardiopulmonary arrest • Gastrointestinal bleed • Hypovolemia, sepsis, and death • Seizures or coma • • • • • • • Prognosis • Guarded to poor, but depends on severity and cause of disease • Guarded to poor long term due to progression of disease Urine Output • Anuria: ≤0.1 mL/kg/hr • Oliguria: ≤0.25 mL/kg/hr • Nonoliguria: ≥2 mL/kg/hr • Approximately 75% of the kidney must be nonfunctional before an elevation in serum BUN and creatinine is seen. 6 Notes Anemia Dehydration and constipation Gastroenteritis Hypertension Uremic stomatitis Urinary tract infection Weight loss Table 6.53 / Urology: Urinary Tract Obstruction and Urinary Tract Infection Disease Presentation Definition 296 Urinary Tract Obstruction Urinary Tract Infection (Cystitis, Urethrocystitis) An obstruction restricting the flow of urine along the pathway from the kidneys to the external urethral orifice. The obstruction can be from blood clots, urethral plugs, uroliths, and sloughed tissue fragments. Urinary tract infection is usually bacteria-induced inflammation of the lower urinary tract including the bladder and urethra. The cause is due to an ascending bacterial infection from the urethral orifice or hematogenous. Clinical Signs • Anorexia, crouching, depression, dysuria, hematuria, lethargy, pollakiuria, ↑ size and velocity of urine stream, stranguria, vomiting • Dysuria, hematuria, malodorous, periuria, pollakiuria, stranguria, urinary incontinence Examination Findings • Abdominal pain, bradycardia, dehydration, distended urinary bladder, hypothermia, renomegaly • Thickened, firm contracted bladder wall SECTION THREE: DIAGNOSTIC SKILLS Table 6.53 / Urology: Urinary Tract Obstructin and Urinary Tract Infection (Continued) Follow-Up Treatment Diagnosis Disease Urinary Tract Obstruction Urinary Tract Infection (Cystitis, Urethrocystitis) General • History/clinical signs • Abdominal palpation: kidneys and bladder • History/clinical signs: recent catheterization or urinary tract surgery • Abdominal palpation: kidneys and bladder • Digital rectal examination: prostate in males Laboratory • • • • Imaging • Radiographs, abdominal: anatomic abnormalities, extended bladder, calculi, urethral plugs, tumors or urachal diverticula • Contrast: urethral strictures, tumors, radiolucent uroliths or vesicourachal diverticula • Ultrasound, abdominal: anatomic abnormalities, extended bladder, calculi, tumors, or urachal diverticula • Radiographs, abdominal: anatomic abnormalities, calculi, tumors or urachal diverticula • Contrast: radiolucent calculi • Ultrasound, abdominal: anatomic abnormalities, calculi, tumors, or urachal diverticula Procedures • Cystoscopy • ECG: bradycardia, atrial standstill • N/A General • • • • • Symptomatic Medication • Antibiotics: variable • Calcium gluconate • Sodium bicarbonate • Antibiotics: variable Nursing Care • Monitor bladder size and urine output. • Treated as outpatient Patient Care • Monitor urine output and hydration status. • Culture urine 1 week and 1 month after beginning treatment. • Allow frequent access to litter box or outdoors. Prevention/ Avoidance • Dependent on cause of obstruction • Avoid glucocorticoid use or urethral catheterization. Complications • • • • • Pyelonephritis • Cystic calculi • Recurrence Prognosis • Good with early detection and correction CBC: ± stress leukogram Chemistry panel: ↑ phosphorus, potassium, ↓ calcium and azotemia Urinalysis: ↑ blood, protein, crystals Blood gases: metabolic acidosis Fluid therapy Urohydropulsion Surgery: urethrotomy, urethrostomy Lithotripsy Reobstruction UTI Urinary bladder rupture Urethral trauma during catheterization • • • • Chemistry panel: ↑ BUN, creatinine and azotemia Urinalysis: pyuria, ↑ blood, protein, bacteria, specific gravity Urine culture: bacteria isolation and identification Prostatic fluid analysis: bacteria and neutrophils • Excellent CHAPTER 6 / GENERAL MEDICINE 297 6 Table 6.53 / Urology: Urinary Tract Obstructin and Urinary Tract Infection (Continued) Disease Urinary Tract Obstruction Urinary Tract Infection (Cystitis, Urethrocystitis) Notes • Caution: Due to the patient’s compromised state, chose anesthetics carefully. • Fluid therapy should not be started until obstruction is relieved. Significant Bacteria Count Canine Cystocentesis: ≥1000 Catheter: ≥10,000 Voided: ≥100,000 Expressed: ≥100,000 6 298 SECTION THREE: DIAGNOSTIC SKILLS Feline ≥1000 ≥1000 ≥10,000 ≥10,000 Chapter 7 Emergency Medicine Emergency Medicine 301 Emergency Supplies 301 Telephone Assessment and Emergency Transportation Recommendations 304 Inducing Vomiting At-Home 305 Triage 306 Primary Survey 306 Hemostasis 307 Cardiopulmonary Cerebrovascular Resuscitation (CPCR) 308 Secondary Survey 309 Shock 310 Cardiac Emergencies 312 Environmental Emergencies 313 Gastrointestinal Emergencies 314 Hematologic Emergencies 315 Metabolic and Endocrine Emergencies 316 Neonatal Emergencies 317 Neonatal Resuscitation Post-Cesarean 317 Neurologic Emergencies 318 Ophthalmic Emergencies 319 Renal and Urinary Emergencies 320 Reproductive and Genital Emergencies 321 Respiratory Emergencies 322 Toxicologic Emergencies 323 Toxins 324 Trauma Emergencies 326 7 299 Key Words and Termsa Abducted Ambulation Anisocoria Ataxia Azotemia Cathartics Cyanosis Decerebellate posture Decerebrate resposne Dyschezia Dystocia Ecchymoses Edema Epistaxis Flail chest Hematemesis Hematochezia Hemoptysis Hyperemic Hyperesthesia Hyperreflexia Hyperthermia Hypertonia Icterus Incontinence Intraosseus Intussusception 7 a Isoerythrolysis Lacrimation Lymphadenopathy Melena Mentation Micturition Mydriasis Nystagmus Oliguria Pallor Paradoxical respiration Paraphimosis Philtrum Pollakiuria Polydipsia Polyuria Ptyalism Pulse deficits Purulent Schiff-Sherrington’s posture Scleral injection Septicemia Strabismus Stranguria Triage Key words and terms are defined in the glossary on page 631. 300 SECTION THREE: DIAGNOSTIC SKILLS Abbreviations Additional Resources, page ACT, activated clotting time ACTH, adrenocorticotropic hormone ANA, antinuclear antibody ASPCA, American Society for the Prevention of Cruelty to Animals BP, blood pressure BUN, blood urea nitrogen Ca2+, Calcium cm H2O, centimeters of water CNS, central nervous system CPCR, cardiopulmonary cerebrovascular resuscitation CRT, capillary refill time CT, computed tomography CVP, central venous pressure DOCP, desoxycorticosterone acetate ECG, electrocardiogram ET, endotracheal tube Fr, French GDV, gastric dilatation volvulus GIT, gastrointestinal tract GV, governing vessel H2O2, hydrogen peroxide HR, heart rate IV, intravenous kg, kilogram mg, milligram mm Hg, milliliters of mercury MM, mucous membranes MRI, magnetic resonance imaging NPO, nothing by mouth NSAIDs, nonsteroidal anti-inflammatory drugs PCV, packed cell volume pH, potential of hydrogen RR, respiratory rate Tb, tablespoon TP, total protein URI, upper respiratory infection UTI, urinary tract infection Abdominocentesis, 429 Blood culture, 122 Blood gas analysis, 335 Blood pressure, 332 Blood transfusions, 367 Bone marrow evaluation, 83 Cardiopulmonary, 30 Central venous pressure, 334 Cesarean section, 542 Chest drain, 431 Coagulation tests, 115 Coupage, 432 CPCR, 308 Diagnostic peritoneal lavage, 429 Disinfectants, 627 Electrocardiogram, 338 Endoscopy, 551 Enema, 430 Fecal analysis, 134 Fine needle biopsy, 89 Fluid therapy, 359 Fluorescein sodium stain, 430 Gastric lavage, 428 Heat administration, 346 Laboratory, 71 Nebulization, 432 Neurologic examination, 34 Nutritional support, 413 Orthopedic examination, 36 Otoscopic examination, 33 Oxygen therapy, 375 Pain management, 379 Patient monitoring, 332 Pericardiocentesis, 431 Pharmacology, 567 Physical examination, 18 Pulse oximetry, 463 Radiology, 157 Recumbent patient care, 347 Shirmer tear test, 430 Stomach tube, 428 Surgery, 521 Thoracocentesis, 431 Tonometry, 430 Tracheostomy, 377 Ultrasound, 197 Urinalysis, 147 Urinary catheter maintenance, 436 Urinary catheter placement, 435 Urine collection, 434 Ventilator, 474 Vital signs, 19 Emergency Medicine Emergencies typically happen at the most inconvenient times. A well-stocked clinic and a staff trained in handling emergencies will make your team more efficient and each emergency therefore less stressful. Each member of the clinic should have a specific job during emergencies. Understanding the basics of what constitutes an emergency as well as being able to perform stabilizing and monitoring techniques is essential to assisting the veterinarian. This chapter covers the basic supplies, support, and monitoring techniques necessary to handle an emergency. It also gives a very general coverage of emergencies by body system. All diagnoses and treatment prescriptions can be done only by the veterinarian. These tables are to assist the technician in monitoring the patient. The technician then will be able to alert the veterinarian of abnormalities and to carry out the veterinarian’s treatment therapy where applicable. Please note that this chapter is not meant to be “all inclusive,” and we urge each clinic to have a thorough emergency resource library in the clinic. Table 7.1 / Emergency Supplies Before any emergency patient arrives at the hospital, a crash cart should be assembled and diligently maintained to be available to assist the veterinarian and staff. Each clinic will have preferences regarding supplies and should set up their supplies to suit their needs. The items listed are examples of what may be needed and are not meant to be all inclusive. The most important part of the selected emergency supplies is familiarity. Each staff member must know his or her location and understand their use and operation. This knowledge will lead to a smooth recovery attempt. 7 Crash Cart • The items contained in the crash cart are the first items utilized in an emergency. These items should be dedicated to emergencies and are not used for daily purposes. One person should be designated to maintain the crash cart on a regular basis and to alert staff to any changes. Supplies • Stethoscope • IV catheters of various sizes, caps, T-ports, and tape • Syringes and needles (regular, spinal, intraosseus) of various sizes • Blood collection tubes • Fluid delivery system (IV fluid bags and IV administration tubing) • Clippers and surgical scrub • Masks and gloves • Minor surgical instrument pack (scalpel handle, thumb forceps, needle holders, and 3 hemostats of various sizes) • Scalpel blades • Suture material of various types • Endotracheal tubes of various sizes, laryngoscope, local anesthetic, ties, cuff syringe, and mouth gags • Urinary catheters for intratracheal injection Equipment • Defibrillator • Electrocardiograph Drugs • • • • Drug dose chart Atropine Ca2+ chloride or gluconate Dexamethasone sodium phosphate • • • • Dextrose Diazepam (if lock box available) Epinephrine Lidocaine 2% • IV fluids (LRS, dextran 70, hypertonic saline, hetastarch) • Sodium bicarbonate • ± Phenobarbital (if lock box available) Basic Equipment • These items provide basic support to the patient. These supplies may not necessarily be in the crash cart due to size and multiple hospital uses, but their location is known and easily accessible. CHAPTER 7 / EMERGENCY MEDICINE 301 Table 7.1 / Emergency Supplies (Continued) Supplies • • • • Bandaging material Lubricating jelly Thermometer Heat support • • • • Blood pressure equipment Blood gas analyzer Pressurized fluid infusion cuff IV fluid warmer • Oxygen delivery system (ambu bag, line to oxygen source, humidifier) • Pulse oximetry • Nebulizer Specialized Equipment • These items are advanced equipment used in specific, critical situations. These items may not necessarily be in the crash cart due to size and multiple uses, but their location is known and easily accessible. • Respirator • Suction supplies (suction tubing, jar, pump) • Tracheostomy pack • Thoracotomy pack • Pericardiocentesis pack • Abdominocentesis pack Drugs • This listing of drugs includes most of those used to treat critical patients. These drugs are typically kept in their regular location, the exception to the drugs listed in the crash cart. These drugs are used for treatment and not for immediate life-threatening situations. 7 Cardiac Drugs • Antiarrhythmics • Diltiazem, dexamethasone sodium phosphate, esmolol, lidocaine, procainamide, propranolol, verapamil • Diuretics • Furosemide • Inotropes • Digoxin, dobutamine, dopamine, isoprenaline, isoproterenol • Vasodilators • Acepromazine, hydralazine, nitroglycerin ointment, nitroglycerin patch, captopril, diltiazem, sodium nitroprusside, amlodipine besylate, enalapril • Sedatives • Morphine, butorphanol, buprenorphine • Other • Aspirin (antithrombotic therapy) • Ca2+ chloride (ventricular asystole) • Glycopyrrolate • Heparin (antithrombotic therapy) • Potassium chloride (chemical defibrillator) • Bronchodilators • Cholinergic blockers, antihistamines, beta-2-adrenergic agonists (epinephrine, isoproterenol, albuterol), Methylxanthines (aminophylline) • Stimulants • Doxapram hydrochloride, naloxone, yohimbine • Antiulcer • H2-receptor antagonists (cimetidine, famotidine, ranitidine), antacids (magnesium hydroxide), gastromucosal protectants (sucralfate) • Misoprostol • Proton pump inhibitors (omeprazole) • Laxatives • Enemas, milk of magnesias, and glycerin • Emetics • apomorphine, xylazine, ipecac syrup, hydrogen peroxide • Protectants/adsorbents • Bismuth subsalicylate, kaolin/pectin, activated charcoal Respiratory Drugs • Antitussives • Butorphanol tartrate, hydrocodone bitartrate, codeine, dextromethorphan, Temaril-P Gastrointestinal Drugs • Antidiarrheals • Narcotic analgesics • Antiemetics • Chlorpromazine, prochlorperazine, anticholinergics, metoclopramide 302 SECTION THREE: DIAGNOSTIC SKILLS Table 7.1 / Emergency Supplies (Continued) Neurologic Drugs • Antiseizuring • Diazepam, phenobarbital • Muscle relaxant • Methocarbamol • Rapid-acting corticosteroids • Methylprednisolone sodium succinate • Topical anesthetics • Proparacaine hydrochloride, tetracaine • Stains • Fluorescein strips • Ca2+ channel blockers • Diltiazem, verapamil • Diuretics • Furosemide, mannitol 20%, glucose • Urinary alkalizers • Potassium citrate, sodium bicarbonate (oral) • Vasodilators • Hydralazine, dopamine, dobutamine • R-insulin • Percorten (DOCP) • Pralidoxime (against organophosphates) • Fomepizole/Antizol-Vet (against ethylene glycol—dogs only) • Hemostatic agent • Vitamin K1 • Antihistamine • Diphenhydramine Ophthalmic Drugs • Reduces Intraocular pressure (IOP) • Carbonic anhydrase inhibitors, timolol maleate, mannitol, glycerol Renal/Urinary Drugs • ACE inhibitors • Captopril, enalapril • Antidiuretics • Vasopressin 7 Reproductive Drugs/Hormones • Oxytocin Toxicologic Drugs—Antidotes • Antidotes • Acetylcysteine (against acetaminophen) • Dimercaprol (against arsenical compounds) • Ethanol (against ethylene glycol) CHAPTER 7 / EMERGENCY MEDICINE 303 Table 7.2 / Telephone Assessment and Emergency Transportation Recommendations When a client calls with an emergency situation, asking very specific questions and advising the owner on how to assess the situation, provide initial treatment, and move the animal are very important. Before beginning the assessment, inquire as to whether the owner and the animal are in a safe place. In any traumatic emergent situation, it is advisable to place a muzzle on the animal if no respiratory distress is noted and mucous membranes are pink. Recommendations listed below should be altered if the animal becomes aggressive or the procedure produces additional stress. Always ask the owner what is their expected arrival time. This will allow the staff to make any preparations necessary prior to their arrival. The goal of dealing with an emergency situation is to minimize stress of both the owner and the patient. Questions may need to be asked multiple times to maintain the attention of the upset and distracted owner. Regardless of the nature of the injury, if the owner perceives it as an emergency, it must be handled in that manner. On-Site Questions to the Client Recommendations What is the nature of the injury? Have the owner give a quick assessment of the situation and the extent of the injuries. Based on this information, further questions can be asked. Traumatic 7 • Hit by car, poisoning, seizures, drowning, fall, lacerations, fractures, and eye injuries • Is your animal awake or unconscious? • Does your animal respond to your commands? • If the animal is unconscious, it needs to be rapidly assessed for breathing and circulation. • Is your animal breathing? • Is your animal having trouble breathing? • Animals in respiratory distress should have limited activity during transport and be allowed to maintain a position of comfort. • Animals not breathing should be given mouth-to-nose resuscitation and chest compressions during transport. Frequently, this will stimulate spontaneous breathing if initially caused by a vasovagal reflex. • See Skill Box 7.3 Cardiopulmonary Cerebrovascular Resuscitation (CPCR), page 308. • What is the color of your animal’s mucous membranes? • Compare the mucous membranes to your own—Are they more white, blue, or red? • If white or blue, assess for breathing and circulation. • Palpate the chest for a heartbeat or feel for a jugular pulse. • Does your animal have external bleeding? • Is it pulsating? • Apply direct pressure to the site of bleeding and elevate above the heart. • Leashes or ropes can be used as tourniquets placed proximal to the injury with arterial pulsating bleeding. • Does your animal have a limb in an abnormal position? • Is he limping or not bearing any weight on the limb? • Support fractures believed to be below the elbow or hock. • Secure the fractured limb with a roll of newspaper, magazine, board, or piece of cardboard with pieces of fabric or duct tape. • If this causes additional stress, gently transport the animal on thick fabric or a board (thin wood or cardboard). Acute • GDV, poisoning, GIT obstruction, hives, vaccine reaction, respiratory complications • Is your animal having a seizure? • If diabetic, administer Karo syrup orally. • Transport in a large towel for protection of the owner and animal; only loosely cover the animal during transport to avoid hyperthermia. • Does your animal have a distended abdomen? • Avoid pressure on the abdomen. • Do not allow the animal to eat or drink in transport. • If nonambulatory, transport on thick fabric or a board (thin wood or cardboard). 304 SECTION THREE: DIAGNOSTIC SKILLS Table 7.2 / Telephone Assessment and Emergency Transportation Recommendations (Continued) • Has your animal eaten something poisonous? If so, when? • Remove the animal from the toxin. • Bring any remaining substance and/or packaging, vomit, or feces. • If no other symptoms are present, call Poison Control Center and possibly induce vomiting (e.g., hydrogen peroxide). • See Skill Box 7.1, page 305 and Chapter 17 Pharmacology, page 593. • Is your animal vomiting or have diarrhea? • Bring in samples. • Is your animal gagging/retching? • Try to comfort the animal to decrease these symptoms. • Is your animal choking? • If possible, observe the inside of the mouth for an obstruction to be removed. • Administer a sharp blow with the palm of your hand between the shoulder blades. • Perform a modified Heimlich procedure—With the animal beside you and head forward, place arms around abdomen with fist just behind the ribs, compress the abdomen 3–5 times with quick inward-up pushes, check the mouth for the foreign body, and repeat 1–2 more times if necessary. Chronic • UTI, kennel cough, URI 7 • What is your animal’s ability to urinate? • Avoid pressure on the abdomen. • Is your animal coughing? • Once arriving at the clinic, leave your animal in the car while checking in. • Is your animal in labor? • Place the delivered neonates in a box with heat support (warm water bottles or heating pad wrapped in a towel). • Gently transport the female as she may be quite uncomfortable. Skill Box 7.1 / Inducing Vomiting At-Home Inducing vomiting is a very common treatment for a foreign body or toxic ingestions. However, care must be taken before giving this advice or performing the procedure as it can be more dangerous to bring the item back up versus letting the animal digest or pass the item. For example, alkalis, acids, corrosive agents, petroleum products, or hydrocarbons should not be expelled, and animals with preexisting conditions such as epilepsy, cardiovascular disease, debilitated, or recent abdominal surgery or those with a potential for gastric torsion should avoid induced vomiting. One of the best resources for accurate information is the Poison Control Center (800-222-1222) or the ASPCA Poison Control Center (888-426-4435 with a possible consultation fee). Vomiting at-home is best performed using hydrogen peroxide (H2O2) within 2–3 hours postingestion with expectation of getting 40–60% of the stomach contents expelled. Three percent H2O2 produces mild gastric irritation leading to vomiting. Higher strengths or overdosing will lead to severe gastritis, especially in cats. If no vomiting occurs after the second dose, the animal should be brought in for administration of apomorphine and/or other treatments. H2O2 Dose 1 mL (1 tsp) per lb. to a maximum dose of 45 mL (3 Tb) This dose may be repeated 1 time in 10 minutes. Tips for a Successful At-Home Procedure 1. Verify the H2O2 is a 3% strength. 2. Verify the H2O2 has not expired. 3. Feed a small meal, e.g., 1–2 pieces of bread. 4. Administer the H2O2. a. Mix with equal parts of milk or ice cream (1 Tb. H2O2 + 1 Tb. milk). b. Use a liquid medicine syringe, sports squirt bottle, or turkey baster. 5. Exercise the animal (e.g., playing fetch, quick walk). CHAPTER 7 / EMERGENCY MEDICINE 305 Triage When presented with an animal suffering a life-threatening problem, a successful outcome requires hospital readiness, effective teamwork, practiced triage skills, and a rapid response to primary survey abnormalities. “Triage” is the process of giving priority to those patients with the most critical problems. This begins with the assessment of the 3 major body systems: respiratory, cardiovascular, and neurologic. This quick primary survey will allow the best approach to treatment to be continued during the secondary survey. The primary survey is a brief physical examination. Many details are ascertained simultaneously to obtain the information quicker. Even though obvious injuries can be alarming, the patient must have a stable cardiovas- cular and respiratory system before other injuries are addressed. Begin the assessment as you approach the animal, evaluating the presenting clinical signs. Next, address any arterial vessel injury. Respirations can then be appreciated with auscultation while also evaluating the heart. If no respirations are heard, oxygen supplementation via ET tube or tracheostomy should be done. The heart should have clear decisive sounds heard from either side and should be evaluated in conjunction with the peripheral pulse. The patient’s capillary refill time, mucous membrane color, and body temperature should also be evaluated. Any alterations should be addressed (e.g., CPCR, drug administration, debrillator, etc.) to stabilize the patient. The central nervous system should also be evaluated through pupillary response and position, reflexes, and presenting clinical signs. Table 7.3 / Primary Survey 7 Presenting Clinical Signs Physical Examination Causes Immediate Action • No passage of air • Loud inspiratory or expiratory sounds • Altered breathing patterns • ↑ Respiratory effort, dyspnea • Change in mucous membrane color • • • • • • • • Respiratory distress Complete or partial obstruction Upper airway trauma or rupture Pneumothorax Hemothorax Pulmonary contusions Diaphragmatic hernia Flail chest • Oxygen therapy • Intubate orally or by slash tracheostomy • Remove foreign object manually or by a modified-Heimlich maneuver • CPCR • Change in mucous membrane color and moisture • Delayed capillary refill time • Pulse presence and intensity • Heart rate and rhythm • Hyper- or hypothermia • Cold extremities • Crackles in lung fields on auscultation • • • • • Arterial or venous injury Heart failure Thromboembolism Pleural effusion Pulmonary edema • • • • • Respiratory • • • • • • Panting (feline) Paradoxical respiration Open mouth breathing Coughing ↑ or ↓ Respiratory rates Extended head or neck with abducted elbows • Nasal flare Cardiovascular • • • • • External hemorrhage Panting Weakness, collapse Abdominal distention Cough, exacerbated with activity or exercise 306 SECTION THREE: DIAGNOSTIC SKILLS Hemostasis Oxygen therapy CPCR Thoracocentesis/pericardiocentesis ECG monitoring Table 7.3 / Primary Survey (Continued) Presenting Clinical Signs Physical Examination Causes Immediate Action • Pupillary response, size, and position • Eye position: strabismus, nystagmus • Motor reflexes • Pain response • Hyperthermia • Hypertonia • Hyperflexia • • • • • • • Oxygen therapy • Anticonvulsants • Changes in conformation, limb angles • Pain response • Bleeding soft tissue wounds • Trauma Central Nervous System • • • • Level of consciousness Head position Seizuring Ambulation • Severe front end rigidity and hindend weakness: Shiff-Sherrington Syndrome • Generalized weakness/paresis Heat trauma Intoxication Spinal cord injury Seizures Infections; bacterial, parasitic Vestibular syndrome Body Condition • • • • • Lacerations Fractures/malalignments Eye injuries Abdominal distention Burns • Oxygen therapy • Analgesics • Wound care: keep moist with a sterile water soluble lubricant and sterile dressing • Fractures: clip, examined, stabilize Skill Box 7.2 / Hemostasis Controlling hemorrhage can be a first-line defense against shock, allowing the patient to maintain an adequate volume of blood. Initially, direct digital pressure can be placed to provide hemostasis. This can be direct pressure over the injury (or if an extremity or tail) by encircling the area proximal to the injury and applying pressure. Sterile dressings should always be used to avoid contamination of the wound. Pressure wraps can be placed for hemostasis. If the wrap becomes soaked, another wrap should be placed on top of the first. Tourniquets should be avoided as they can cause tissue and nerve damage within minutes. With arterial hemorrhage, the artery should be clamped and ligated when possible. If that is not possible, direct pressure should be placed on a pressure point following one of the techniques below dependent on which artery is compromised. Area of Hemorrhage Pressure Point Area of Hemorrhage Pressure Point • Maxillary artery • Deep area adjacent and ventral to the mandible • Inguinal artery • Caudal abdomen • Brachial artery • Axillary area • Distal extremity artery • BP cuff placed proximal to the injury with a pressure of 200 mm Hg • Femoral artery • Inguinal and femoral canal region CHAPTER 7 / EMERGENCY MEDICINE 307 7 Skill Box 7.3 / Cardiopulmonary Cerebrovascular Resuscitation (CPCR) CPCR should ideally be conducted on an adjustable height solid table. Depending on the size of the animal and staff, it may be necessary to provide a stool or perform the procedure on the floor. A surgical grated prep table should not be used for CPCR as it does not provide the counterpressure needed for chest and abdominal compressions. The steps below should be assigned to various team members so that the animal’s resuscitation is conducted as smoothly and thoroughly as possible. 7 A. Airway Alert the emergency team of upcoming arrival of patient. Assess the airway. • Extend the patient’s head and neck and pull tongue forward; remove any debris manually or with suction. • Establish a patent airway with endotracheal intubation or a slash tracheostomy. B. Breathing Assess breathing. • Confirm apnea. • Provide mechanical ventilation via an Ambu bag or anesthetic machine with 100% oxygen at a rate of 150 mL/kg/min. • Initiate with 2 breaths for 2 seconds each. • Reassess for spontaneous respiration. • If none, continue at 12–20 breaths/min (1 breath/3–5 seconds) and attempt acupuncture to stimulate respiration. (Place a 25-gauge needle into the midline just below the nose [philtrum] at acupuncture point governing vessel [GV] 26. Penetrate the skin and subcutaneous tissue from 2 to 4 mm. Rotate the needle up and down at this point to stimulate the site.) • Each breath should have an expiration slightly longer than inspiration and a manometer pressure reading of: • Canine pressure: ≤20 cm H2O • Feline pressure: ≤15 cm H2O C. Circulation Assess circulatory function. • Confirm absence of heart beat and peripheral pulses. • External cardiac compression • Provides ∼30% of normal cardiac output • Check for femoral or carotid artery pulse repeatedly throughout this process. • Animal weighing <7 kg: lay in right lateral recumbency and start compressions with 1 or 2 hands over the 3–5 intercostal space. • Animal weighing >7 kg: lay in right lateral or dorsal recumbency and start compressions with the palm of the hands over the distal 1/3 of the rib cage. • Use enough force to displace the thorax 30%. • Respirations are given with every or every other compression. • Abdominal compressions are given between chest compressions. • One person: 5 compressions, then 1 ventilation. • Two people: 1 compression, then 1 ventilation. • Three people: 1 compression, 1 ventilation, then 1 abdominal compression. • Internal cardiac compression • Provides 60–90% more effective cerebral and coronary perfusion • Preferred method with rib fractures, pleural effusion, pneumothorax, cardiac tamponade, diaphragmatic hernia, flail chest • Initiated after 5 minutes if effective tissue perfusion is not seen 308 SECTION THREE: DIAGNOSTIC SKILLS Skill Box 7.3 / Cardiopulmonary Cerebrovascular Resuscitation (CPCR) (Continued) • Initiated after 10 minutes is spontaneous rhythm has not returned • Place in left lateral recumbency and a thoracotomy is performed at the 5th–6th intercostal space. • The palm and fingers are used to pump the heart in a rhythmic fashion. D. Drugs (atropine, epinephrine, lidocaine, naloxone, magnesium chloride) E. Evaluation of the patient with a thorough examination ECG F. Fibrillation Control Fluids Table 7.4 / Secondary Survey After the primary survey, the patient is classified as stable, potentially unstable, or unstable. Following this determination, resuscitation of vital functions and stabilization of life-threatening problems takes place. Once stable, a thorough past and current medical history, physical examination, and laboratory database are obtained. This is followed by reassessment of the original treatments. Secondary Survey History and Procedures Past Medical History • • • • • Medical conditions Drug therapies Allergies Vaccination history Previous transfusions Current Medical History • • • • • • • • • • Presenting complaint When animal was last normal Chronology and progression of signs Potential toxin ingestion Physical trauma Signs of collapse, weakness or ↓ ability to exercise Signs of abnormal neurologic behavior Travel history Access to other animals Affinity to eat abnormal things Physical Examination • Vital signs • Evaluation of organ systems not involved • See Chapter 2 Physical Examination, page 18. Stat Lab Database • • • • PCV, TP Chemistry panel and electrolytes Complete blood count Urinalysis CHAPTER 7 / EMERGENCY MEDICINE 309 7 Table 7.5 / Shock Shock is typically the result of poor oxygen delivery. The goal, regardless of form, is to optimize oxygen delivery. The most effective way to improve oxygen delivery is to ↑ cardiac output by optimizing preload with fluid administration. Cardiogenic Shock Septic Shock Definition Diminished blood volume leading to tissue perfusion failure. Tissue perfusion failure due to inadequate cardiac output Circulatory disorder due to bacteria or bacterial endotoxin release Cause Hemorrhage, fluid loss (e.g., burns, vomiting, diarrhea, ↑ urine production), poor venous return (e.g., GDV), severe GIT bleed, severe epistaxis, addisonian crisis (e.g., hypotension) Cardiomyopathy, cardiac tamponade, cardiac arrhythmias, heartworm disease, pulmonary hypertension, pulmonary thromboembolism, pericardial disease, heart failure, valvular disease with decompensation GIT compromise/rupture, urinary tract infection (UTI), septic peritonitis, pneumonia, bacterial endocarditis, bite wounds, myelosuppression, prostatitis Presenting Clinical Signs • Muscle weakness, mental depression • Muscle weakness or collapse, mental depression, cough, labored breathing • Extreme weakness, mental depression Primary Survey Findings Compensatory stage: bounding pulses, cool extremities, pale or hyperemic mucous membranes, hypertension, delayed CRT, tachycardia, tachypnea Decompensatory stage: hypotension, hypothermia, ↓ mental status, oliguria, pale or muddy mucous membranes, delayed CRT, poor peripheral pulses, tachycardia or bradycardia Abnormal heart sounds (e.g., gallop, murmur), arrhythymias, cardiac tamponade (tachycardia, weak pulses, hepatomegaly, jugular distention), cool extremities or hypothermia, dyspnea or tachypnea, harsh lung sounds or crackles, pale or cyanotic mucous membranes, prolonged CRT, variable HR and RR, weak femoral pulses and pulse deficits Compensatory stage: bounding pulses, dyspnea or tachypnea, hyperemic mucous membranes, hypertension, mental depression, pyrexia, rapid CRT (<1 second), tachycardia, weakness Decompensatory stage: cool extremities, GIT bleeding (hematemesis, hematochezia), pale mucous membranes and delayed CRT, peripheral edema, petechiation, poor peripheral pulses, tachycardia or bradycardia, tachypnea Equipment • Crash cart • Basic emergency equipment • Specialized emergency equipment • Crash cart • Basic emergency equipment • Specialized emergency equipment • Crash cart • Basic emergency equipment • Specialized emergency equipment Medication • • • • • • • • • • • • • • • Presentation Hypovolemic Shock Preparation 7 Emergent Condition 310 Blood plasma transfusions Positive inotropes Steroid therapy (short-acting) Vasopressor agents IV crystalloids/colloids SECTION THREE: DIAGNOSTIC SKILLS Antiarrhythmics Diuretics Positive inotropes Vasodilators Antibiotics Blood/plasma transfusions Positive inotropes Sodium bicarbonate Steroids Vasopressor agents Table 7.5 / Shock (Continued) Emergent Condition Diagnostics / Treatments Procedures Patient Care Monitoring Hypovolemic Shock Cardiogenic Shock Septic Shock • • • • • • • • • • • • • • • • BP CVP ECG Endoscopy Hemostasis Imaging: • Thoracic radiographs • ± Abdominal radiographs • Ultrasonagraphy • Lab tests: • ACT • Blood gas analysis • Coagulation profile • Stat lab database • Oxygen therapy • Thoraco- or abdominocentesis • General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds, tidal volume, respiratory pattern, SpO2 • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, ECG, CVP • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis, lactate • • • • BP CVP ECG Imaging: • Thoracic radiographs • Echocardiography Lab tests: • Blood gas analysis • Stat lab database Oxygen therapy Pericardiocentesis Pulse oximetry • • • • • General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, ECG, CVP, SpO2 • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis Abdominocentesis, arthrocentesis BP CVP ECG Endoscopy Imaging: • Thoracic radiographs • Echocardiography • Ultrasonagraphy Lab tests: • ACT • Blood cultures • Blood gas analysis • Coagulation profile • Stat lab database Oxygen therapy Surgery Wound care 7 • General: general behavior, muscle strength, body temperature • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, BP, mucous membranes, CRT, CVP, ECG, SpO2 • Renal: urine output • Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes, blood gas analysis CHAPTER 7 / EMERGENCY MEDICINE 311 Table 7.6 / Cardiovascular Emergencies Diagnostics / Treatments Patient Care 7 Preparation Presentation Emergent Condition 312 • Atrial or ventricular septal defect, cardiac arrest, cardiac arrhythmias, cardiac tear, cardiomyopathy, caval syndrome, congestive heart failure, heartworm disease, hypertension, infective endocarditis, left- and/or right-sided heart failure, patent ductus arteriosus, pleural effusion, pulmonary edema, pulmonic or aortic stenosis, severe ascites, subvalvular aortic stenosis, tetrology of Fallot, thromboembolism, tricuspid dysplasia, valvular, tamponade, or pericardial disease Presenting Clinical Signs • Abdominal distention, anxiety, depression, exercise intolerance, head extended ± hemoptysis, lethargy, acute blindness, resistance to restraint/movement, sudden lameness, syncope, weakness/collapse, abdominal respiration, dyspnea ± cough or muffled sounds, open-mouth breathing, tachypnea Primary Survey Findings • Abdominal swelling, ascites, cold extremities, mydriasis, weakness, dull heart sounds, harsh lung sounds, delayed CRT, dysrhythmias, jugular vein distention, murmurs, pale or cyanotic mucous membranes, tachycardia with weak or bounding pulses, hepatomegaly, dehydration, hypotension, oliguria Equipment • Basic crash cart equipment • Specialized crash cart equipment • Radiography Medication • • • • Procedures • • • • • Bilateral thoracocentesis or pericardiocentesis (with ECG monitoring) CVP Pulse oximetry ECG Lab tests: • Stat lab database • Arterial blood gas analysis • Blood culture (pericardial fluid) • Imaging: • Thoracic radiographs • Oxygen therapy and positive pressure ventilation Monitoring • General: Body temperature, body weight, pain management, minimal patient handling, calm and quiet environment, support in sternal position to elevate the head and neck to facilitate cerebral blood flow, heat support and warming of extremities • Respiratory: RR and effort, lungs sounds • Cardiovascular: HR and rhythm, pulse rate and quality, femoral pulses (feline), BP, mucous membranes, CRT, ECG, CVP, thoracic radiographs • Renal: Urine output, hydration • Lab tests: Electrolytes, BUN, creatinine, blood gas analysis SECTION THREE: DIAGNOSTIC SKILLS β-Blockers Diuretics Sodium influx inhibitors Positive inotropes • Tranquilization • Vasodilators • Sympathomimetics Table 7.7 / Environmental Emergencies Patient Care Diagnostics / Treatment Preparation Presentation Emergent Condition • Drowning, electrocution, frostbite, heatstroke, hypothermia Presenting Clinical Signs • Ataxia, burns, collapse, diarrhea, epistaxis, hematemesis, hematochezia, hemoptysis, hypersalivation, listlessness, loss of consciousness, muscle tremors, shivering, vomiting, dyspnea, moist cough, panting, seizures Primary Survey Findings • Hyper- or hypothermia, hypotension, localized swelling, oral sensitivity, petechiation, tissue necrosis, pulmonary edema, respiratory arrest, cardiac arrthythmias, pale or cyanotic mucous membranes, tachy- or bradycardia, weak or hyperdynamic pulses Equipment • Basic crash cart equipment • Radiography Medication • • • • • • Procedures • ECG • Imaging: • Thoracic radiographs • Lab tests: • Stat lab database • Coagulation profiles • Blood gas analysis • Intubation and positive end-expiratory pressure • Oxygen therapy • Temperature control Monitoring • • • • • Antibiotics Anticonvulsants Bronchodilators Diuretics Gastric protectants Steroids 7 General: Pain management, nutritional support Respiratory: RR and effort Cardiovascular: HR and rhythm, BP, ECG Renal: Urine output Lab tests: Blood gas analysis CHAPTER 7 / EMERGENCY MEDICINE 313 Table 7.8 / Gastrointestinal Emergencies Preparation Presentation Emergent Condition Presenting Clinical Signs • Abdominal distention/pain, anxiety, diarrhea, dyschezia, hematochezia, hypersalivation, lethargy, melena, nonproductive retching, pawing at mouth, polydipsia, restlessness, vomiting (hematemesis) Primary Survey Findings • Cyanosis, distended abdominal veins, ecchymoses, halitosis, hyperthermia, periumbilical hemorrhage, petechiation, ↓ femoral pulses, weak or rapid pulse, ↓ CRT, dehydration Equipment • • • • Basic crash cart equipment Endoscopy Radiography Ultrasonography Medication • • • • • Analgesics Antacids Antibiotics Antidiarrheal Antiemetics Procedures • Abdominocentesis, ± diagnostic peritoneal lavage • CVP • Lab tests: • Stat lab database • ACT • Coagulation profile • Fecal analysis (direct, flotation, parvovirus test) • Urinalysis • Imaging: • Abdominal radiographs, ± contrast studies • Utrasonograph • Endoscopy (foreign body retrieval) • Laparotomy Monitoring • General: Pain management, NPO for hours to days with gradual introduction of a bland diet, turn recumbent patients every 2–4 hours, neck should be kept slightly elevated if concern of regurgitation or aspiration • Respiratory: RR and effort • Cardiovascular: HR and rhythm, pulse rate and strength, BP, mucous membranes, CRT, ECG, CVP • Gastrointestinal: Inappetence, defecation, vomiting • Renal: Urine output, hydration • Lab tests: PCV, TP, electrolytes, BUN, amylase, lipase, blood glucose, albumin, white blood cell count Patient Care Diagnostics / Treatment 7 314 • Acute gastritis, acute hepatic failure, acute intussusception, acute pancreatitis, bowel perforation, colitis, constipation, alimentary foreign bodies/obstructions, GDV, hemorrhagic gastroenteritis, parasitic infections, poisons, rectal prolapse, gastroduodenal ulcer disease SECTION THREE: DIAGNOSTIC SKILLS • • • • • Dextrose Gastric protectants Motility modifiers Plasma therapy Sedation Table 7.9 / Hematologic Emergencies Patient Care • Anemia, hemorrhage, immune-mediated thrombocytopenia, coagulopathies Presenting Clinical Signs • Anorexia, collapse, epistaxis, exercise intolerance, fleas/ticks, hematochezia, bruising, hematoma, hemoptysis, hemorrhage, lethargy, melena, muscle wasting, pica, syncope, weakness, weight loss, hematuria Primary Survey Findings • Ecchymoses, gingival bleeding, hypothermia, icterus, joint pain or swelling, lymphadenopathy, organomegaly, pallor, petechiation, dyspnea, murmurs, tachycardia, weak/thready or pounding pulses Equipment • • • • Basic crash cart equipment Specialized crash cart equipment Radiography Utrasonograph Medication • • • • • • • • • Anticoagulants Antiparasiticidals Blood products Chemotherapy agents Gastric protectants H2-blockers Proton pump inhibitors Steroids Vitamin K Procedures • BP • Bone marrow biopsy • Imaging: • Thoracic and abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Reticulocyte count • Bone marrow evaluation • Coombs’ test • Coagulation profile • Fecal analysis • Bleeding time tests • ANA titer • von Willebrand test • Oxygen therapy Monitoring • • • • Diagnostics / Treatment Preparation Presentation Emergent Condition 7 General: Body temperature Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm, BP, CVP, SpO2 Lab tests: PCV, TP, urinalysis, ACT CHAPTER 7 / EMERGENCY MEDICINE 315 Table 7.10 / Metabolic and Endocrine Emergencies Treatment 316 • Diabetes mellitus, diabetic ketoacidosis, hyper- or hypocalcemia, hyper- or hypokalemia, hyper- or hyponatremia, hypoadrenocorticism (Addison’s), hypoglycemia, hypoproteinemia, metabolic acidosis, metabolic alkalosis, thyrotoxicosis Presenting Clinical Signs • Anorexia, ataxia, coma, diarrhea, dry and flaky skin, hypersalivation, Kussmaul breathing, lethargy, muscle tremors, panting, plantigrade stance, polydipsia, polyphagia, polyuria, restlessness, seizures, vomiting, weakness, weight loss Primary Survey Findings • Blindness, epigastric pain, hyper- or hypothermic, ketotic breath, muscle wasting, severe depression, weight loss, dehydration, hypotension Equipment • Basic crash cart equipment • Blood glucose monitor • Electrolyte analyzer (e.g., VetTest, I-stat) Medication • • • • • • Procedures • Lab tests • Stat lab database • ACTH stimulation test • ECG Monitoring • • • • • Patient Care 7 Preparation Presentation Emergent Condition SECTION THREE: DIAGNOSTIC SKILLS Antiemetic Anti-inflammatory Bone resorption inhibitors Dextrose Diuretics Fluid therapy (± sodium bicarbonate, dextrose, or electrolytes) • Insulin therapy (insulin adheres to plastic, flush tubing with 30–50 mL of insulin before beginning treatment) • Mineralocorticoids (e.g., Florinef, Percorten-V) • Supplements • Ca2+ • Phosphorous • Potassium General: Mental and neurological status, body temperature, body weight, pain management Respiratory: RR and effort, lung sounds Cardiovascular: Pulse, ECG Renal: Urine output Lab tests: PCV, TP, electrolytes, BUN, creatinine, blood glucose, Ca2+, phosphorous, blood gas analysis, urinalysis Table 7.11 / Neonatal Emergencies Patient Care Treatment Preparation Presentation Emergent Condition • Conjunctivitis, dehydration, severe dermatitis, dysphagia, hypoglycemia, hypothermia, hypoxia, infectious diseases, intussusception, juvenile cellulitis, neonatal isoerythrolysis, heavy parasitic load, septicemia, umbilical infection Presenting Clinical Signs • Anorexia, bloating, crying, depression, diarrhea, edematous rectum, facial swelling, fever, lethargy, limp, poor muscle tone, relaxed, tremors, unthriftiness, vomiting, weight loss, seizures Primary Survey Findings • Coma, deep pyoderma, GIT paralysis, hypothermia, lymphadenopathy, pale, gray or cyanotic mucous membranes, palpable intussusception, poor bowel sounds, ↓ respirations, tachy- or bradycardia, dehydration Equipment • Basic crash cart equipment • Warming cage or unit Medication • • • • • • Antibiotics Blood transfusion Dextrose Respiratory stimulants Steroids Vitamin K 7 Procedures • Lab tests: • Stat lab database • Blood glucose • Fecal analysis (direct, flotation, parvovirus test) • Bacterial culture samples (whole blood, urine, feces, exudate) • Oxygen therapy Monitoring • General: Mentation, body temperature, body weight, heat support (gradual warming over 30–60 minutes), turn every hour, nutritional support • Respiratory: RR and effort, lung sounds • Cardiovascular: HR and rhythm, mucous membranes, CRT • Renal: urine output, hydration • Lab tests: PCV, TP, blood glucose Skill Box 7.4 / Neonatal Resuscitation Post-Cesarean There are many methods that can be used to stimulate a neonate to begin spontaneous respirations. A delivered neonate should be immediately placed in a dry towel with an assistant. The neonate is dried off by rubbing vigorously with the towel to lessen the chances of hypothermia and to stimulate respirations. The neonate should be examined for any obstructive secretions or fluid obstructing the airway. If spontaneous respirations do not begin, the assistant may employ 1 or more of the following techniques: • While supporting the head and neck to avoid whiplash or concussive injury, swing the neonate in a large downward arc to clear fluid in the chest via centrifugal forces and gravity. • Place 1–2 drops of doxapram hydrochloride sublingually. • Use the acupuncture point governing vessel (GV) 26. Hold the neonate with its head elevated above its heart and its neck extended, and place a 25-gauge needle into the midline just below the nose (philtrum). Penetrate the skin and subcutaneous tissue 2–4 mm, and stimulate the site by rotating the needle up and down. • Provide artificial respiration by placing a 20-gauge catheter endotracheally or by blowing gently into the nose and mouth (normal, 15–40 breaths/ min). CHAPTER 7 / EMERGENCY MEDICINE 317 Table 7.12 / Neurologic Emergencies Preparation Presentation Emergent Condition Presenting Clinical Signs • Aggression, agitation, ataxia, blindness, circling, coma, depression, disorientation, epistaxis, head tilt, head tremors, leaning, loss of balance/coordination, loss of motor ability, mastication, nystagmus, paralysis, paresis, salivation, stupor, vomiting, hyperventilation, seizures Primary Survey Findings • ↓ Facial sensation, anisocoria, anorexia, ataxia, Horner’s syndrome, hyperreflexia, hyperthermia, hypertonia, otitis media/ interna, pain, paresis, reflex deficiencies, Cheyne-Stokes respiration, decerebellate rigidity, decerebrate rigidity, SchiffSherrington’s posture Equipment • Basic crash cart equipment Medication • • • • Procedures • BP • Lab tests: • Stat lab database • Blood gas analysis • Lead levels • Serology for infectious diseases • Ear cytology • Myelography, spinal tap, MRI • Otoscopic examination • Oxygen therapy Monitoring • General: Mentation, body temperature, pain management, elevate the front end 20–30° to ↑ cerebral venous drainage and avoid pressure on the neck • Respiratory: RR and effort, respiratory pattern, SpO2 • Cardiovascular: HR and rhythm, pulse rate and quality, BP • Neurologic: Pupil size and response, motor activity, deep pain assessment, posture, vision • Lab tests: PCV, TP, blood glucose, blood gas analysis Patient Care Treatment 7 318 • Bacterial infections, cancer/tumors, comas, head injuries, metabolic imbalances with secondary CNS changes, parasitic infestations, seizures, spinal cord injuries, toxins, vestibular syndrome SECTION THREE: DIAGNOSTIC SKILLS Anticonvulsants Antibiotics Diuretics Steroids Table 7.13 / Ophthalmic Emergencies • Bite wounds/scratches, chemical burns, corneal laceration/abrasion/perforation/ulcer, descemetocele, severe ectropion, enophthalmos, severe entropion, foreign bodies, glaucoma, hyphema, keratoconjunctivitis sicca, lens luxation, orbital cellulitis, panophthalmitis, proptosed globe, retrobulbar mass, symblepharon, uveitis • Blindness, corneal color change, discharge, pain, pawing or rubbing the eye, photophobia, running into objects, squinting Primary Survey Findings • ↑ or ↓ intraocular pressure, absent papillary light reflex, aqueous flare, blepharospasm, bulb protusion, corneal edema, dilated pupil, inability to blink, inability to retract eye, lacrimation, loss of visual acuity, miotic pupil, negative menace response Equipment • • • • • Black light Fluorescein strips Ophthalmoscope Schirmer tear test strips Tonometer Medication • • • • • • • Antiglaucomas Diuretics Miotics Mydriatics Steroids Topical anesthetics Topical antibiotics Diagnostics / Treatment Presenting Clinical Signs Procedures • Imaging: • Skull radiographs • CT Scan • Lab tests: • Stat lab database • Ophthalmic examination: • Tonometer • Schirmer tear test • Fluorescein stain • Surgery Patient Care Preparation Presentation Emergent Condition Monitoring • General: Elizabethan collar, pain management • Ophthalmic: discharge, worsening of previous clinical signs 7 CHAPTER 7 / EMERGENCY MEDICINE 319 Table 7.14 / Renal and Urinary Emergencies Preparation Presentation Emergent Condition Presenting Clinical Signs • Anorexia, ataxia, crying, depression, dysuria, lethargy, vomiting, pollakiuria, polydipsia, polyuria, stranguria, seizures Primary Survey Findings • Distended and/or painful abdomen, halitosis, hyper- or hypothermia, oral ulcerations, scleral injection, tachypnea, bradycardia, pale mucous membranes, anuria, dehydration, distended bladder, hematuria, large painful firm kidneys, polydipsia, polyuria Equipment • • • • • Basic crash cart equipment Radiology Ultrasonography Urinary catheters; variety of types (rigid, Foley, feeding tubes) and sizes (3.5–14 Fr) Closed urinary collection system Medication • • • • • • Antibiotics Antiemetics Diuretics Metabolic disorder drugs (e.g., Ca2+, dextrose, insulin) Gastric protectants Sodium bicarbonate Procedures • • • • • Monitoring • • • • • Patient Care Treatment 7 320 • Acute or chronic late-stage renal failure, azotemia, bacterial infection, bladder/ureter/urethra ruptures, feline lower urinary tract disease, pyelonephritis, severe cystitis, toxins, urinary obstructions, uroliths SECTION THREE: DIAGNOSTIC SKILLS BP CVP Cystocentesis ECG Imaging: • Abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Urine culture • Ethylene glycol testing • Leptospirosis titers • Surgery • Urethral catheterization, normograde, retrograde, hydropropulsion General: Elizabethan collar, body weight, pain management, nutritional support Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm Renal: Urine output, hydration, pH, specific gravity Lab tests: PCV, TP, electrolytes, BUN, creatinine, Ca2+, phosphorus, blood glucose, blood gas analysis Table 7.15 / Reproductive and Genital Emergencies Patient Care • Male: Acute prostatitis, acute scrotal dermatitis, fractures of the os penis, infectious orchitis, laceration of the penis, paraphimosis, scrotal neoplasia, testicular torsion, • Female: Acute metritis, dystocia, eclampsia, pyometra, septic mastitis, uterine prolapse/torsion/rupture, vaginal prolapse/neoplasia Presenting Clinical Signs • Male: Depression, difficulty urinating/defecating, licking genital area, pain, purulent or bloody discharge from the urethra, vomiting, walking difficulties • Female: Depression, pain, panting, restlessness, salivation, vomiting, walking difficulties, licking genital area, unproductive labor/delivery, vaginal discharge Primary Survey Findings • Male: Abdominal pain, extended penis, inappetence, unilateral swelling of testicles • Female: Active straining for >60 minutes without delivery of a fetus, anorexia, fever, foul-smelling or purulent vulvar discharge, hot/swollen/painful mammary glands, muscle weakness, time delay between pups/kittens >4–5 hours Equipment • • • • Basic crash cart equipment Specialized crash cart equipment Radiology Ultrasonography Medication • • • • • Antibiotics Analgesics Ecbolic agents Metabolic imbalances (e.g., Ca2+, potassium, insulin, dextrose) NSAIDs Procedures • Imaging: • Abdominal radiographs • Ultrasonography • Lab tests: • Stat lab database • Vaginal cytology • Blood gas analysis • Manual manipulation, hyperosmotic topical therapy to shrink tissues • Surgery Monitoring • • • • Treatment Preparation Presentation Emergent Condition 7 General: Mentation, body temperature, Elizabethan collar, pain management Cardiovascular: HR and rhythm Renal: Urine output Lab tests: PCV, TP, electrolytes, BUN, creatinine, liver enzymes CHAPTER 7 / EMERGENCY MEDICINE 321 Table 7.16 / Respiratory Emergencies • Aspiration pneumonia, brachycephalic occlusive syndrome, bronchitis, cancer, collapsing trachea, diaphragmatic hernia, feline asthma, flail chest, tracheal and bronchial foreign bodies, hemothorax, laryngeal paralysis, lung contusions, lung parenchymal issues, pleural effusion, pneumomediastinum, pneumonia, pneumothorax, pulmonary edema, smoke inhalation, soft tissue swellings, tracheal stenosis Presenting Clinical Signs • Abduction of elbows, cough, flared nostrils, head straightened, hemoptysis, lips drawn back, neck extended, preference to stand or lie in sternal recumbency, reluctance to hold mouth closed, subcutaneous emphysema, wheezing, apnea, dyspnea, open mouth breathing Primary Survey Findings • Hyperthermia, ↑ respiratory rate and effort, abnormal respiratory sounds (e.g., laryngeal stridor), irregular respiratory pattern, change in mucous membranes color, tachycardia Equipment • Basic crash cart equipment • Specialized crash cart equipment Medication • • • • • • Antibiotics Bronchodilators Cough suppressants Diuretics Steroids Tranquilizers Procedures • • • • Airway suctioning Bronchioalveolar lavage Chest tube placement Imaging: • Thoracic radiographs • Tracheoscopy, bronchoscopy for foreign body retrieval Lab tests: • Stat lab database • Blood gas analysis • Heartworm tests • Fecal analysis • Fluid analysis Oxygen and/or ventilator therapy Surgery Thoracocentesis Tracheostomy, nasal catheter, transtracheal catheter Transtracheal wash Treatment • • • • • • Patient Care 7 Preparation Presentation Emergent Condition 322 Monitoring SECTION THREE: DIAGNOSTIC SKILLS • General: Pain management, minimal patient handling, calm and quiet environment, turn recumbent patients every 2–4 hours, use harnesses instead of collars • Respiratory: RR and effort, lung sounds, nebulization/coupage • Cardiovascular: HR and rhythm, pulse quality and rate, BP, mucous membranes, SpO2 • Renal: Urine output • Lab tests: Blood gas analysis Table 7.17 / Toxicologic Emergencies Patient Care • Bacterial/fungal toxins, food ingredient (e.g., grapes, onions), household compounds/chemicals, household plants, insecticides, herbicides, medication ingestions/overdoses, pesticides, rodenticides, zinc ingestion Presenting Clinical Signs • Ataxia, coma, diarrhea, hyperexcitability, hypersalivation, muscle tremors, progressive depression, stupor, vomiting, weakness, dyspnea, seizures, anuria Primary Survey Findings • Abdominal pain, facial edema, hyperthermia, mouth odor, cardiac arrhythmias, cyanosis, pallor mucous membranes, urinary incontinence, vomiting Equipment • Basic crash cart equipment • Specialized crash cart equipment Medication • • • • • • • Procedures • • • • • • Monitoring • • • • • • Treatment Preparation Presentation Emergent Condition Anticonvulsants Antidote (if available and specific toxin identified) Antiemetics Diuretics Emetics Gastrointestinal protectants Muscle relaxants 7 Bathing, rinsing ECG Enemas Emesis Gastric lavage and charcoal administration Imaging: • Radiographs • Lab tests: • Stat lab database • Ethylene glycol testing • Coagulation testing General: Mentation, body temperature Respiratory: RR and effort Cardiovascular: HR and rhythm, pulse rate and quality, CVP Neurologic: Tremors, seizures Renal: Urine output Lab tests: Electrolytes, BUN, creatinine, urinalysis CHAPTER 7 / EMERGENCY MEDICINE 323 Table 7.18 / Toxins The goals with poisoning are always the same—prevent further exposure, ↓ absorption, hasten elimination, and provide supportive care. The prognosis for each situation depends on the toxin, quantity, and time delay from initial exposure to toxin. 7 Toxin Toxic Doses Clinical Signs Treatment Acetaminophen Canine: 150 mg/kg Feline: 50–60 mg/kg Onset: hours to days • Brown mucous membranes and blood, depression, facial or paw edema, hepatic necrosis, hypothermia, icterus, vomiting, weakness, cyanosis, dyspnea, tachypnea, keratoconjunctivitis sicca (canine) • Emesis, gastric lavage, cathartics, oxygen therapy, blood transfusions, diuresis, cimetidine, ascorbic acid • Antidote: 5% N-acetylcysteine (NAC) solution Amphetamines 1.3 mg/kg Onset: variable • Agitation, circulatory collapse, coma, hyper- or hypotension, hyperactivity, hypertension, hyperthermia, mydriasis, pallor or hyperemic mucous membranes, ptyalism, restlessness, tremors, tachypnea, cardiac arrhythmias, tachycardia, seizures • Emesis, gastric lavage, activated charcoal, cathartics, oxygen therapy • Antidote: chlorpromazine Ethylene glycol Canine: 4–6 mL/kg Feline: 1.5 mL/kg Onset: 30 minutes–12 hours • Ataxia, coma, depression, knuckling, lethargy, nystagmus, vomiting, tachypnea, tachycardia, polydipsia, polyuria, seizures • Blacklight detection, emesis, gastric lavage, supportive care • Antidote: 20% ethanol (feline), 4-methylpyrazole (canine) Ibuprofen Canine: 100 mg/kg Feline: 50 mg/kg Onset: 1–4 hours • Abdominal pain, anorexia, coma, depression, diarrhea, hematemesis, melena, polyuria, stupor, vomiting, seizures Emesis, gastric lavage, activated charcoal, GIT protectants, diuresis Metaldehydes • Snail and slug bait 100 mg/kg Onset: 1–4 hours • Anxiety, ataxia, hyperesthesia, hypersalivation, hyperthermia, incoordination, nystagmus, pulse irregularities, tremors, bradypnea, tachy- or bradycardia, seizures • Milk, emesis, gastric lavage, activated charcoal • Antidote: none Organophosphates • Sprays, dusts, dips Variable Onset: variable • Colic, diarrhea, hypersalivation, lacrimation, miosis, tremors, vomiting, bronchoconstriction, excessive bronchial secretions, bradycardia, seizures, frequent urination • Bathing, activated charcoal, cathartics, anticholinergics • Antidote: pralidoxime chloride Pyrethrins/pyrethroids • Sprays, dips, foggers Variable Onset: variable • Anorexia, ataxia, depression, diarrhea, disorientation, hyperactivity, hyperexcitability, hypersalivation, muscle twitching, tremors, vocalization, vomiting, bradycardia, dyspnea, seizures • Bathing, emesis, gastric lavage, activated charcoal, cathartics, anticholinergics • Permethrin Onset: 3–72 hours • Tremors, seizures • Bathing (liquid hand soap), methocarbamol, barbiturates, and/or propofol Insecticides 324 SECTION THREE: DIAGNOSTIC SKILLS Table 7.18 / Toxins (Continued) Toxin Toxic Doses Clinical Signs Treatment Lily Onset: 2 hours • Anorexia, depression, vomiting, polyuria • Emesis, activated charcoal, cathartics Mushrooms Variable Onset: 6–8 hours • Abdominal pain, ataxia, coma, defecation, depression, diarrhea, DIC, hallucinations, hyperthermia, lacrimation, nausea, salivation, vomiting, seizures, urination • Emesis, gastric lavage, activated charcoal, cathartics, bowel irrigation, oxygen therapy, supportive care Pseudoephedrines 5–6 mg/kg Onset: 15–30 minutes • Agitation, head bobbing, hyperactivity, hypertension, hyperthermia, mydriasis, panting, tremors, cardiac arrhythmias, tachycardia, seizures • Emesis, gastric lavage, activated charcoal, GIT protectants, diuresis Anticoagulant • Warfarin, pindone, bromadiolone, brodifacoum, chlorphacinone, difethialone, diphacinone, coumafuryl, dicoumarol, difenamrol Variable Onset: 6 hours–2 days • Anorexia, blindness, depression, ecchymoses, epistaxis, exercise intolerance, frank and petechial hemorrhage, hematemesis, hematochezia, lameness, lethargy, melena, pale mucous membranes, paralysis swollen joints, weakness, cough, dyspnea, hematuria • Emesis, activated charcoal, cathartics, blood transfusions, oxygen therapy • Vitamin K therapy Bromethalin Canine: 4.7 mg/kg Feline: 1.8 mg/kg Onset: immediate–2 weeks • Anisocoria, CNS depression, excitement, forelimb extensor rigidity, head pressing, hyperesthesia, hyperexcitability, hyperthermia, loss of vocalization, paralysis, paresis, Schiff-Sherrington posture, tremors, weakness, seizures • Emesis, gastric lavage, activated charcoal, cathartics, bowel irrigation, supportive care, diuretics, steroids, Ginkgo biloba • Antidote: none Cholecalciferol • Vitamin D3 0.1 mg/kg Onset: 12–36 hours • Anorexia, constipation, depression, hematemesis, hypertension, lethargy, muscle weakness, petechiation, vomiting, ventricular fibrillation, polydipsia, polyuria, seizures • Emesis, gastric lavage, activated charcoal, cathartics, diuretics, steroids • Antidote: calcitonin, pamidronate Snakebite envenomation Variable Onset: immediate • Dilated pupils, edema, fang marks, hemorrhages, pain, salivation, swelling, tachycardia • Supportive care • Antidote: antivenin, trivalent crotalidae, atropine Spider bite envenomation Variable Onset: immediate-weeks • Abdominal rigidity, hypersalivation, hypertension, muscle spasms and rigidity, pain, restlessness, salivation, respiratory distress, bronchorrhea • Supportive care • Antidote: antivenin, dantrolene sodium, Dapsone Theobromine • Chocolate 10–15 mg/kg Milk chocolate: 44 mg/oz theobromine Baking chocolate: 390 mg/ oz theobromine Onset: 2–4 hours • Abdominal pain, agitation, ataxia, bloating, coma, cyanosis, diarrhea, hyper- or hypotension, muscle tremors, vomiting, cardiac arrhythmias, tachycardia, seizures, hematuria, polydipsia, polyuria, urinary incontinence • Emesis, gastric lavage, activated charcoal, cathartics, supportive care, ECG, urinary catheter • Anticonvulsants and antiarrhythmics Plants Rodenticides CHAPTER 7 / EMERGENCY MEDICINE 7 325 Table 7.19 / Trauma Emergencies Preparation Presentation Emergent Condition Presenting Clinical Signs • Depression, fractures, lacerations, limping, loss of consciousness, pain, panting, shivering, shock, seizures Primary Survey Findings • Burns, hemoptysis, hemorrhage, hyper- or hypothermia, necrosis of lips/tongue, pain, petechiation, dyspnea, irregular lung sounds, patterns and rates, maligned or deformed limbs, pneumomediastinum, pneumothorax, pulmonary edema, subcutaneous emphysema, thoracic or abdominal effusion, tachy- or bradycardia Equipment • Basic crash cart equipment • Specialized crash cart equipment Medication • • • • Procedures • • • • • Monitoring • • • • • Patient Care Treatment 7 326 • Animal attack, burns, fractures, hit by car, lacerations SECTION THREE: DIAGNOSTIC SKILLS Analgesics Antibiotics Blood transfusions Corticosteroids Abdominal tap/abdominal pressure wrap Bandaging, splinting, and basic wound care ECG Heat support Imaging: • Thoracic and abdominal radiographs • Spinal and skull radiographs • Ultrasonography • Lab tests: • Stat lab database • Blood gas analysis • Oxygen therapy • Surgery General: Mentation, body temperature, pain management, immobilize as needed Respiratory: RR and effort, lung sounds Cardiovascular: HR and rhythm, pulse rate and quality, BP, ECG, CVP, SpO2 Renal: Micturition reflex, urine output Lab tests: PCV, TP, electrolytes, BUN, blood glucose, blood gas analysis, platelet count Section Four Patient Care Skills Chapter 8: Patient Care 329 Chapter 9: Pain Management 379 Chapter 10: Wound Care 395 Chapter 11: Parenteral Nutrition 413 Chapter 12: Medical Procedures 427 Chapter 8 Patient Care Patient Monitoring 332 Blood Pressure 332 Blood Pressure Procedure 332 Blood Pressure Results 333 Central Venous Pressure 334 Blood Gas Analysis 335 Blood Gas Analysis 335 Arterial Blood Gas Interpretation 337 Acid-Base Disturbances 337 Electrocardiogram 338 ECG Procedure 338 ECG Leads 339 ECG Interpretation 340 Figure 8.1 Normal Canine Electrocardiogram 341 Heart Rate Calculation 342 Common Rhythm Abnormalities 343 Figure 8.2 Atrial Premature Contraction/Complex 344 Figure 8.3 ST-Segment Elevation 344 Figure 8.4 Ventricular Premature Contraction/ Complex 344 ECG Problems and Artifacts 345 Heat Administration 346 Recumbent Patient Care 347 Drug Administration 348 Injections 348 Intravenous Catheter Placement 349 Peripheral and Jugular 349 Arterial and Intraosseous 350 Monitoring and Maintenance 351 Chemotherapy 352 Administration 352 Toxicity 353 Client Education: Monitoring Chemotherapy Response 356 Insulin Therapy 357 Client Education: Insulin Administration 357 Client Education: Monitoring Insulin Response 358 Client Education: Monitoring for Hypoglycemia 359 Fluid Therapy 359 Hydration Assessment 360 8 329 Calculating Fluid Requirements 361 Routes of Fluid Administration 362 Commonly Used Fluids 363 Fluid Additives 365 Calculating Drip Rates 365 Monitoring Fluid Therapy 366 Blood Transfusions 367 Blood Types 368 Blood Collection 369 8 330 SECTION FOUR: PATIENT CARE SKILLS Blood Products 371 Blood Administration 373 Blood Transfusion Reactions 374 Oxygen Therapy 375 Oxygen Administration 375 Routes of Oxygen Administration 376 Oxygen Hood and Nasal Catheter 376 Transtracheal Catheter and Tracheostomy 377 Key Words and Phrasesa Acidotic Alkalosis Alloantibody Amplitude Antiemetics Antipyretics Apex Ataxia Bipolar Cachexia Carbohydrate Chemo-pin Crystalloids Cyanosis Decubital Diastolic Electromechanical dissociation Epistaxis Erythema Extracellular Extravasation F wave Fructosamine Glycosylated Hemolyzed Holter apparatus Humidification Hypercalcemia Hyperglycemia Hyperkalemia Hypernatremia Hyperoncotic Hypochloremia Hypoglycemia Hyponatremia Hyporeflexia Immunogenic Infarction a Intracellular Ischemia Isoantibody Manometer Metabolic acidosis Metabolic alkalosis Microaggregates Myelosuppressive Myocardium Nadir Neuropathy Neutropenia Normovolemic Oscillometric Osmotic Osteopenia Papilledema Perfusion Perioperative Petechiae Pollakiuria Polydipsia Polyuria Precordial Prophylaxis Pruritis Repolarization Respiratory acidosis Respiratory alkalosis Serous Stranguria Supraventricular Systolic Tetany Thrombocytopenia Turgor Unipolar Urticaria Vagal Abbreviations APC, atrial premature contraction/complex APTT, activated partial thromboplastin time aVF, augmented voltage foot aVL, augmented voltage left arm aVR, augmented voltage right arm BG, blood glucose BGC, blood glucose curve bpm, beats per minutes BW, body weight C, Celsius CBC, complete blood count CHF, chronic heart failure CO2, carbon dioxide CPCR, cardiopulmonary cerebrovascular resuscitation CPD, citrate phosphate dextrose CPDA-1, citrate phosphate dextrose adenine CRT, capillary refill time CVP, central venous pressure D5W, 5% dextrose in water DEA, dog erythrocyte antigen DIC, disseminated intravascular coagulation DMSO, dimethylsulfoxide ECG, electrocardiogram E-collar, Elizabethan collar ET, endotracheal tube FeLV, feline leukemia virus FFP, fresh frozen plasma FIV, feline immunodeficiency virus FP, frozen plasma Fr, French FUO, fever of unknown origin GFR, glomerular filtration rate H2O, water IM, intramuscular IO, intraosseous IV, intravenous Additional Resources, page KCl, potassium chloride kg, kilogram L, liter LA, left arm lb, pound LL, left leg LRS, lactated Ringer’s solution mg, milligram dL, deciliter min, minute mL, milliliter NaCl, sodium chloride NSAIDs, nonsteroidal antiinflammatory drugs O2, oxygen PCV, packed cell volume PPV, positive pressure ventilation pRBCs, packed red blood cells PT, prothrombin time PZI, protamine zinc insulin R, right RA, right arm RBC, red blood cell RL, right leg SA, sinoatrial SIRS, systemic inflammatory response syndrome SQ, subcutaneous STD, standard SWB, stored whole blood TP, total protein V, voltage VPC, ventricular premature contraction/complex WBC, white blood cell Anatomy, 3 Anesthesia, 439 Blood chemistries, 74 Canine transmissible diseases, 38 Cardiology, 204 Feline transmissible diseases, 44 General medicine, 201 Injections, 348 Laboratory, 71 Nebulization, 432 Nutrition, 57 Radiographs, 159 Surgery, 521 Urinalysis, 147 8 Key words and terms are defined in the glossary on page 631. CHAPTER 8 / PATIENT CARE 331 PATIENT MONITORING Monitoring of a hospitalized patient is one of the crucial responsibilities of a veterinary technician. This section includes some basic monitoring skills; blood pressure, central venous pressure (CVP), cardiac values (ECG readings), and heat administration. See Skill Box 13.8, page 467, and Chapter 9 Pain Management, page 379, for further monitoring information. Blood Pressure Skill Box 8.1 / Blood Pressure Procedure Measuring accurate blood pressures on animals is not trivial, and lots of experience and attention to every detail is important:—limb selection, proper cuff size, snug fit of the cuff, position of the animal—is important so that no weight or pressure is on the measurement limb or cuff, the animal is a relaxed and still. Research has shown that if an animal is upset or agitated due to handling or due to the measurement procedure itself, it will take 8–10 minutes after the animal is calmed and relaxed for the animal’s blood pressure to return to normal. Measurements on an agitated animal are not an indication of their normal blood pressure and are usually worthless clinically when diagnosing a hypertensive animal. 8 Method: Direct Arterial Pressure Doppler Ultrasound Flow Detectors Oscillometric Indications • Monitoring during anesthesia, CPCR, shock, fluid administration, and any other condition leading to secondary hyper- or hypotension • Monitoring during anesthesia, CPCR, shock, and any other condition leading to secondary hyper- or hypotension • Detection of flow in distal limbs (e.g., traumatic wounds, saddle thrombi), corneal flow during CPCR • Irregular pulse signals or rates can indicate cardiac arrhythmias. • Monitoring during anesthesia, CPCR, shock, fluid administration, and any other condition leading to secondary hyper- or hypotension Contraindications • Using large vessels in patients with coagulopathies • Upset or agitated patients • Upset or agitated patients • Upset or agitated patients Setup • Catheter (e.g., arterial, over-the-needle, through-the-needle) • Heparinized saline • Pressure transducer and monitor • Equipment • Ultrasonic gel • Equipment (e.g., petMAP) 332 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.1 / Blood Pressure Procedure (Continued) Method: Direct Arterial Pressure Doppler Ultrasound Flow Detectors Oscillometric Procedure The catheter is placed in an artery (e.g., dorsal pedal, femoral, or auricular) and flushed with 1–1.5 mL of heparinized saline. The catheter is thoroughly secured with tape to avoid dislodging or kinking. The catheter is then labeled to prevent inadvertent intra-arterial injections. The catheter is then connected to the pressure transducer by rigid tubing filled with heparinized saline. Refer to the manufacturer’s guidelines for further setup and monitoring instructions. The method for measuring CVP can also be used if a transducer system is not available. Place the patient in a comfortable position. Select a cuff that has a width that is approximately 40% of the circumference of the patient’s distal limb or tail. Snugly place the cuff on any place an artery is accessible, typically a limb distal to the elbow or hock or the base of the tail. Place the probe over the artery but distal to the cuff, turn on Doppler, and listen for blood flow. Position probe until a clear flow is heard and tape into place. Inflate the cuff and slowly release the trigger until the first flow sound is heard, this is the systolic pressure. The second sound heard is the diastolic, which often cannot be heard. Place the patient in a comfortable position. Select a cuff that has a wdith that is approximately 40% of the circumference of the patient’s distal limb or tail. Snugly place the cuff on any place an artery is accessible, typically a limb distal to the elbow or hock or the base of the tail. Connect the cuff to the monitor and turn on. The cuff is inflated until the artery is occluded and then slowly released until the pulse returns. The systolic, diastolic, and mean arterial pressures and heart rate will be displayed. Complications • Hemorrhage, thrombosis, infection, and necrosis • Poor contact between probe and artery • Poor blood flow, small arteries, movement, shaking, or shivering can lead to inaccurate results. Tip: Doppler: if the skin is dry, rub in ultrasonic gel first and then apply more when placing the probe over the artery. Table 8.1 / Blood Pressure Results The normal and abnormal values for blood pressure measurements are clearly defined in human medicine but have not yet been solidly established in veterinary medicine. The following table shows the ranges currently accepted. a Blood Pressure Normal Abnormala Canine • Systolic: 110–160 mm Hg • Diastolic: 60–100 mm Hg • Mean: 80–120 mm Hg • Systolic: <80 and >160 mm Hg • Diastolic: >100 mm Hg • Mean: <60 and >120 mm Hg Feline • Systolic: 120–170 mm Hg • Diastolic: 70–120 mm Hg • Mean: 80–120 mm Hg • Systolic: <80 and >160 mm Hg • Diastolic: >120 mm Hg • Mean: <60 mm Hg and >120 mm Hg Abnormal results do not necessarily warrant therapy. CHAPTER 8 / PATIENT CARE 333 8 Skill Box 8.2 / Central Venous Pressure The CVP measures the heart’s ability to pump fluids returned to it and also evaluates blood volume compared to blood volume capacity. The pressure within the intrathoracic anterior vena cava is compared to a column of water in a manometer or pressure transducer and oscilloscope. Fluctuations are seen with changes in pressure. An ↑ CVP can indicate a backup of blood due to excessive volume (e.g., fluid overload) leading to ascites, pulmonary edema, pneumothorax, or pneumomediastinum. A ↓ CVP can indicate a ↓ blood volume (e.g., dehydration) leading to hypovolemia. An initial crude estimate of CVP can also be done by evaluating resting jugular distention, then filling and relaxation time with digital occlusion. The jugular vein is clipped and observed: Passive • Observed for tension • Mildly distended: often seen with patients in lateral recumbency • Highly distended: patient standing or in sternal recumbency indicates a ↑ CVP • Flat: indicates ↓ CVP and hypovolemia Active Test • Occluded with digital pressure and observed for filling time and then released and observed for relaxation time • ↓ Filling time: >4 seconds indicates ↓ CVP and hypovolemia • ↓ Relaxation time: >2 seconds indicates right side of the heart may be overloaded as with chronic right-sided heart failure, chronic liver disease, acute heart failure 8 Method Central Venous Pressure Indications • Patients prone to hypertension (e.g., renal or liver failure) Contraindications • Burn, abrasion, or pyoderma over site, severe coagulopathy, hypercoagulable, or thrombosis of chosen vein inhibiting jugular catheter placement Setup • Surgical site preparation materials • IV jugular catheter • Heparinized saline Procedure A jugular catheter is placed and advanced to the cranial vena cava. (See Skill Box 8.9 Intravenous Catheter Placement, Peripheral and Jugular, page 349.) Attach an extension set to the catheter, followed by a 3-way stopcock. Attach the IV fluids to the open line of the stopcock. Attach the manometer to the upright opening of the stopcock. Place the patient in sternal recumbency, and position the manometer at the level of the sternum. Turn off the fluids to the patient and fill the manometer with fluids. Open the extension set and the fluid level will equalize. The level at which the fluids stabilizes is the CVP reading. Repeat twice more for accurate results. Complications • Blood clots or occlusions can ↑ values. • If fluids are not running through the catheter, flush with heparinized saline every hour. 334 SECTION FOUR: PATIENT CARE SKILLS • 3-way stopcock • Bandaging materials • IV fluid set up Skill Box 8.2 / Central Venous Pressure (Continued) Method Central Venous Pressure Results Normal: <8 cm H2O Abnormal: >12–15 cm H2O • Monitor trends over time, not a single reading. Following a Fluid Bolus • Normovolemic: ↑ of 2–4 cm H2O with a return to baseline in 15 minutes • Hypovolemic: ↑ with a rapid return to baseline • Hypovolemic (severe): small or no ↑ Tip: Jugular catheter placement can be verified by the 2–5 mm fluctuations seen on the manometer with each respiration. Blood Gas Analysis 8 Skill Box 8.3 / Blood Gas Analysis Blood gas analysis is used to monitor pulmonary function and the metabolic state of the patient through the delicate balance between carbon dioxide (CO2), bicarbonate (HCO3−), hydrogen (H+), and oxygen (O2). With a change in CO2 or HCO3−, alterations are seen in the body’s pH, ultimately affecting its ability to carry out various enzyme activities. The acid-base equation (CO2 + HCO3 ↔ CO2 + H2O) shows how a change in CO2 or HCO3− can alter the pH. The lungs are primarily responsible for regulating CO2 through respiration, while the kidneys regulate HCO3− through resorption and excretion in the proximal tubule. Because CO2 and HCO3− are the main determinates to the acid-base status (pH) of a patient, a change in one factor can affect the other. For example, it is common to see respiratory changes with metabolic disturbances. The body’s ability to compensate for abnormalities can often mask underlying disturbances, making diagnosis and treatment more difficult. Method Blood Gas Analysis Indications • Patients with respiratory disease and/or metabolic disturbances (e.g., toxins, hypoadrenocorticism, diabetes mellitus, chronic renal failure) Contraindications • Patients taking potassium bromide Setup • • • • • 25-gauge needle with 1 mL syringe Heparin Cork to cap needle or sterile red top tube Ice bath (for temporary storage) Blood gas analyzer CHAPTER 8 / PATIENT CARE 335 Skill Box 8.3 / Blood Gas Analysis (Continued) Method Blood Gas Analysis Procedure A syringe coated with heparin (1,000 U/mL) is used to obtain a blood sample. A full 1 mL of blood should be obtained to avoid any dilution with heparin. All excess air is expelled from the syringe and the sample is analyzed immediately. If temporary storage is required, the sample can be stored at room temperature for <10–15 minutes or <1–2 hours in an ice-bath once placed in a container with a tight-fitting cap (e.g., cork, rubber stopper, red top tube). Arterial • Femoral or lingual artery (use of other peripheral arteries possible) • Hold off for 3–5 minutes or place temporary pressure wrap to prevent hematoma formation. Venous • Jugular, cephalic, or saphenous vein (use of other peripheral veins possible) • Note: The sample must be protected from air to avoid alterations. Complications • Samples stored at room temperature for >20 minutes: ↓ pH • Excessive heparin: ↓ HCO3− Resultsa Normal: Arterial pH: 7.35–7.45 PaCO2: 35–42 mm Hg PaO2: 85–105 mm Hg HCO3−: 20–25 mEq/L BE: −4 to +4 Venous pH: 7.35–7.45 PvCO2: 40–50 mm Hg PvO2: 30–42 mm Hg HCO3−: 20–25 mEq/L BE: −4 to +4 Abnormal: • Single or multiple alterations from above • pH: <7.35, acidemia; >7.45, alkalemia 8 a Slight variations in normal and abnormal results occur throughout literature and instrumentation used. Note: BE: base excess represents the magnitude of acid-base abnormality contributed by metabolic components. 336 SECTION FOUR: PATIENT CARE SKILLS The results of the blood gas analysis are then evaluated to determine the status of the patient. This can often be a tricky process, but the basic interpretation is shown below as a 5-step process. Arterial Blood Gas Interpretation 1. Evaluate the PaO2 and determine if the patient is hypoxemic (needs oxygen). 2. Evaluate the pH and determine if the patient is normal, acidotic or alkalotic. 3. Evaluate the PaCO2 and determine if it supports the pH findings. • Yes: condition is primarily respiratory • No: condition is not primarily respiratory 4. Evaluate the HCO3− and determine if it supports the pH findings. • Yes: condition is primarily metabolic • No: condition is not primarily metabolic 5. Evaluate the parameter not responsible for abnormal condition to assess for compensation. Note: Reprinted with permission from Nancy Shaffran, CVT, VTS (ECC). Table 8.2 / Acid-Base Disturbances 8 Respiratory Acidosis Metabolic Acidosis Respiratory Alkalosis Metabolic Alkalosis Cause • Severe pulmonary disease, airway obstruction, pleural effusion, pneumothorax, flail chest, drug side effects, CNS lesions, cardiac arrest, improper use of mechanical ventilator, diseases of respiratory muscles • Diarrhea, diabetic ketoacidosis, intoxication (e.g., ethylene glycol), hyperphosphatemia, uremic acidosis, post chronic hypocapnia, renal failure • Intrathoracic disease, fear, anxiety, septicemia, hypoxia, fever, severe liver failure, CNS disease, heat stroke • Vomiting, drug administration (e.g., sodium bicarbonate, furosemide), post chronic hypercapnia, severe hypokalemia Clinical Signs • Anxiety, lethargy (chronic), coma (acute), ↑ mentation, hypoxia, papilledema • Hyperventilation, hypotension, ventricular fibrillation, anorexia, vomiting, hyperkalemia • Neurologic (e.g., seizures, tetany), hypokalemia • No reliable signs • +/− ↑ Respiratory rate, effort and depth Blood Gas Analysis • ↓ pH and ↑ PCO2 • ↓ pH and HCO3− • ↑ pH and ↓ PCO2 • ↑ pH and HCO3− Treatment • Oxygen therapy, ventilation support • Treat underlying condition (e.g., thoracocentesis). • Drug administration (e.g., sodium bicarbonate) • Fluid therapy (e.g., 0.9% NaCl−) • Drug administration (e.g., potassium) • Treat underlying condition. CHAPTER 8 / PATIENT CARE 337 Electrocardiogram An electrocardiogram (ECG) is a graphic interpretation of the electrical activity of the cardiac muscle. Its use is required for accurate diagnosis of arrhythmias and conduction disorders. An ECG should be a regular part of any systemic disease workup because life-threatening arrhythmias (e.g., ven- tricular tachycardia, atrial tachycardia) are easily missed on auscultation. Besides physical examination findings indicating an ECG, they are also useful in the preoperative evaluation of geriatrics, in anesthesia monitoring (preoperative, perioperative, and postoperative), and for evaluating the effects of cardiac drugs. This simple procedure provides great diagnostic value and should be routinely used in every veterinary hospital. Skill Box 8.4 / ECG Procedure 8 Method Electrocardiogram Indications • Cardiac arrhythmias and the status of the myocardium • Tachycardia, bradycardia, extra beats, murmurs, cardiomegaly, and electrolyte disturbances • Exercise intolerance, panting, dyspnea, cyanosis, fainting, seizures, and shock Contraindications • If animal is exhibiting severe dyspnea Setup • Equipment • Conducting solution (e.g., alcohol, gel) • Staples or wire sutures Procedure Using a nonconductive table (e.g., formica or metal covered with a blanket or pad), place the patient in right lateral recumbency or, if critically ill, in any position that does not further increase injury or illness. The limbs should be held parallel to each other and not touching. The forelimbs should be perpendicular to the long axis of the body. If using clips, moisten the areas of attachment with conductive gel, paste, creams, or alcohol. Apply the clips and reapply the conductive agent. • RA/LA: proximal to the olecranon and on the caudal aspect (electrodes may need to be positioned halfway between the olcranon and carpus if cadiac interference is seen) • RL/LL: patellar ligament on the anterior aspect • Cardiac: left intercostal space at costochondral junction, dependent on desired unipolar precordial chest lead Small metal plates covered with conductive gel, paste, or creams can be applied to the pads of the feet, or shave the fur and adhere electrode pads (Holter apparatus) for long-term monitoring. To record the activity of the heart, begin by turning on the machine. Position the stylus in the center of the paper and maintain that position throughout the recording. Turn the sensitivity switch to 1 to allow 1 mV input to move the stylus 1 cm (2 large boxes). (Turn the sensitivity switch to 2 if the tracing is small and unclear or turn it to 1/2 if the tracing is large and extending to the top and bottom of the paper.) Turn the record switch to a paper speed of 50 mm/sec and push the standardization button to record the reference size of 1 mV. Record the desired leads: • Turn the lead selector to 1 and record 2 sets (30 large boxes). • Without turning off machine or changing any other parameters, turn the lead selector to 2 and continue through to aVF and CV6LU (V4). • Turn the lead selector to 2 and record 2–4 feet of lead II rhythm strip at 25 mm/sec. • If precordial chest leads are desired, stop recording and reposition chest lead for each reading. Return the lead selector to STD and push the standardized button. Stop recording and remove clips from the patient. Fold up ECG strip and record the patient’s information (e.g., name, position, excitement level) on the strip. 338 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.4 / ECG Procedure (Continued) Method Electrocardiogram Complications • • • • ↑ Stress can exacerbate already critical situations Variations in the body conformation of many dog breeds may alter standard measurements Drug administration (e.g., chemical restraint) may alter recording results If the machine does not have a modern 3-prong plug, attach the ground lead wire to a water pipe or object with a common ground Tip: When recording an ECG strip, it is best to “drive” with both hands. The left hand is placed on the stylus position knob to help maintain a centered tracing, because they tend to wander during long readings or when switching leads. The right hand is placed on the lead selector switch to change through the various leads smoothly. Tip: ECG activity may continue to appear normal even after all mechanical activity has ceased and the patient has no palpable pulse (e.g., deceased) (electromechanical dissociation). Tip: The teeth of the alligator clips may be bent out, flattened, or filed to improve patient comfort. Tip: Conductive gel, paste, and creams are better at lowering the electrical resistance than alcohol and do not evaporate; however, alcohol-soaked pads may be used between the clip and skin. Table 8.3 / ECG Leads Lead Measurement Movement and Electrode Position Use 8 Bipolar Standard Leads I • Measurement between 2 limbs • R arm (−) → L arm (+. ) II • R arm (−) → L leg (+. ) III • L arm (−) → L leg (+. ) • Abnormalities in P-QRST deflections and cardiac arrhythmias • Determining mean electrical axis Augmented Unipolar Limb Leads aVR aVL • Measurement from one limb to a point halfway in between the other 2 limbs • L arm and leg (−) → R arm (+. ) • R arm and L leg (−) → L arm (+. ) • Determining mean electrical axis and heart position • Confirming information gained from other leads • L arm and R arm (−) → L leg (+. ) aVF Unipolar Precordial Chest Leads CV5RL (rV1) CV6LL (V2) CV6LU (V4) V10 • Measurement from the dorsal and ventral surfaces of the heart • The limb leads form a potential equal to that in the center of the heart, allowing voltage to be measured from the center of the heart to the selected location of the chest lead. • R and L arm and L leg (−) → 5th R intercostal space near edge of sternum (+. ) • R and L arm and L leg (−) → 6th L intercostal space near edge of sternum (+. ) • R and L ventricular enlargement, myocardial infarction, bundle branch block, and cardiac arrhythmias • Confirming information gained from other leads • R and L arm and L leg (−) → 6th L intercostal space at costochondral junction (+. ) • R and L arm and L leg (−) → over spinous process of the 7th thoracic vertebra (+. ) CHAPTER 8 / PATIENT CARE 339 Table 8.3 / ECG Leads (Continued) Lead Measurement Movement and Electrode Position Use Esophageal • Measurement from limb and base of the heart • The electrocardiograph is run on and compared with lead I. • L arm → base of heart • Rhythm monitoring and accurate identification of P waves Intracardiac • Measurement is based on the position of the exploring catheter tip placed through a jugular venipuncture and attached to an outside electrode. • Dependent on the position of the exploring catheter tip within the heart • Cardiac arrhythmias (accurate identification of P waves), differentiation between ventricular and supraventricular tachycardia, and for pacing the heart Invasive Leads Table 8.4 / ECG Interpretation 8 a b Cycle Segment Movementa Image Measurementb Action P wave • SA node → R atrium → L atrium → AV node • Positive wave • Width: 0.04 second (2 boxes) • Height: 0.4 mV (4 boxes) • Depolarization of the R and L atrium P-R interval • SA node → ventricle • P wave and ending straight line • Start of the P wave to start of Q wave (R wave if no Q wave) • 0.06–0.13 second (36.5 boxes) • Time delay to allow filling of ventricles QRS • R bundle branch and L bundle branch → apex and ventricular free walls → basal regions of free walls and septum • Negative wave (Q) followed by a tall positive wave (R) and ended with a short negative wave (S) • Start of Q wave to the end of the S wave • Width: 0.05–0.06 second (2.5 boxes) • Height: 2.5–3.0 mV (25–30 boxes) • Depolarization of the ventricles ST interval • Basal regions of free walls and septum → apex and ventricular free walls • Straight line with no deviations • End of the QRS complex to the start of the T wave • Width: 0.2 mV (2 boxes) • Height: 0.15 mV (1.5 boxes) • Early phase of ventricular repolarization T wave • Apex and ventricular free walls • Positive wave • Height: ≤1/4 of the amplitude of the R wave • Repolarization of the ventricles Q-T interval • R bundle branch and L bundle branch → apex and ventricular free walls → basal regions of free walls and septum → apex ventricular free walls • Negative wave (Q), tall positive wave (R), short negative wave (S) ending with a straight line (ST segment) • Start of the Q wave to the end of the T wave • Summation of depolarization and repolarization of the ventricles Electrical impulse movement through the heart. Measurement taken at a paper speed of 50 mm/sec. 340 SECTION FOUR: PATIENT CARE SKILLS 8 Figure 8.1 Normal canine electrocardiogram. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins. CHAPTER 8 / PATIENT CARE 341 Skill Box 8.5 / Heart Rate Calculation ECG Paper and Grid Lines 25 mm/sec Small box = 0.04 second Large box (5 small boxes) = 0.20 second Set (15 large boxes) = 3 seconds Rhythm 50 mm/sec Small box = 0.02 second Large box (5 small boxes) = 0.10 second Set (15 large boxes) = 1.5 seconds Paper Speed 25 mm/sec 50 mm/sec • Average Heart Rate Method 1: the number of complete complexes in 1 set × 20 = bpm Method 1: the number of complete complexes in 1 set × 40 = bpm • Instantaneous Heart Rate Method 2: 1500 / the number of small boxes between 2 QRS complexes = bpm Method 2: 3,000 / the number of small boxes between 2 QRS complexes = bpm Method 3: 300 / the number of large boxes between 2 QRS complexes = bpm Method 3: 600 / the number of large boxes between 2 QRS complexes = bpm Regular Rhythm 8 Method 4: heart rate calculator used according to provided directions Irregular Rhythm • The fraction of the last cycle should be estimated in tenths 342 The number of cycles in 2 sets × 10 = bpm SECTION FOUR: PATIENT CARE SKILLS Method 1: the number of cycles in 2 sets × 20 = bpm Method 2: the number of cycles in 4 sets × 10 = bpm • Greater accuracy with slower rates Table 8.5 / Common Rhythm Abnormalities Rhythm Pattern Cause Image Associated Conditions Atrial Fibrillation • Rapid and disorganized depolarization pattern in the atria • ↓ Cardiac output • Indistinguishable P waves are replaced by numerous F waves. • QRS complexes may be normal or wide with varying amplitude. • Atrial enlargement, congenital heart defects, drug reactions, anesthesia, heartworm disease, trauma, or hypertrophic cardiomyopathy Atrial Premature Contraction/ Complex (APC) • Premature atrial beats originating outside the SA node • Premature P wave • QRS complexes are normal unless the P wave is so premature they overlap with varying results. • See Figure 8.2. • Congenital heart disease, cardiomyopathy, electrolyte imbalances, neoplasia, hyperthyroidism, drug reactions, toxemias, atrial myocarditis, or normal variations in aged animals Respiratory Sinus Arrhythmias • Irregular sinus rhythm originating in the SA node • Respiratory rate ↑ during inspiration and ↓ during expiration • Normal sinus rhythm • ↑ Number of cycles during inspiration and ↓ number of cycles during expiration • Normal finding (brachycephalic), vagal stimulation, and chronic respiratory diseases ST-Segment Depression • Net electrical event of myocardial cell repolarization • Depression of the ST segment of the QRS complex • Normal finding, myocardial ischemia (inadequate circulation), hyper- or hypokalemia, cardiac trauma, or acute myocardial infarction ST-Segment Elevation • Net electrical event of myocardial cell repolarization • Elevation of the ST segment of the QRS complex • See Figure 8.3. • Normal finding, myocardial hypoxia (oxygen deficiency), myocardial infarction, or pericarditis Ventricular Fibrillation • Weak and uncoordinated ventricular contractions • ↓ To zero cardiac output • Completely irregular, chaotic, and deformed reflections of varying width, amplitude, and shape • Shock, anoxia, trauma, electrolyte imbalances, drug reactions, aortic stenosis, cardiac surgery, electric shock, myocarditis, or hypothermia Ventricular Premature Contraction/Complex (VPC) • An impulse originating in the ventricles instead of the SA node • P wave is dissociated from the QRS complex. • Widened and bizarre QRS complex • See Figure 8.4. • Cardiomyopathy, congenital defects, GDV, drug reactions, myocarditis, cardiac neoplasia, hyperthyroidism, or chronic valvular disease CHAPTER 8 / PATIENT CARE 8 343 Figure 8.2 Atrial premature contraction/complex. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins. 8 Figure 8.3 ST-segment elevation. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins. Figure 8.4 Ventricular premature contraction/complex. Reprinted with permission from Larry Patrick Tilley: Essentials of Canine and Feline Electrocardiogram Interpretation and Treatment, 3rd ed. Philadelphia, 1992, Lippincott Williams and Wilkins. 344 SECTION FOUR: PATIENT CARE SKILLS Table 8.6 / ECG Problems and Artifacts Alteration Problem Solution Baseline not well defined • Poorly defined baseline • ↑ the stylus heat and verify whether it is clean • ↓ sensitivity to 1/2 to ↓ the amplitude of the wave Flat line • An electrode has fallen off • Replace electrode that has fallen off: • Lead I works and leads II and III do not—replace L leg • Lead II works and leads I and III do not—replace L arm • Lead III works and leads I and II do not—replace R arm Negative R wave • True abnormality • Misplaced electrode • Verify that the electrodes are placed in the correct position. QRS complex off the paper • Excessive amplitude of QRS complex • ↓ Sensitivity to 1/2 to ↓ the amplitude of the wave Rapid and irregular vibrations of the baseline • Muscle tremors • Body movements • Purring • • • • Regular sequence of 60 sharp up and down waves • Electrical interference • Verify the machine is properly grounded. • Verify the electrode clips are clean, securely attached to skin, and moistened (not saturated) with gel or alcohol. • Verify that the legs are held apart and the clips are not touching each other, and the animal is not touching anything metal (e.g., table). • Verify that the table is not touching electrical cords and is positioned away from electrical wiring. • Verify that the cords are not tangled or coiled up on one another. Up and down movement of baseline • Respiratory movements (e.g., panting and coughing) Verify the patient is in a comfortable position and electrodes are comfortably placed. Place a hand over the chest wall with moderate pressure to ↓ body tremors. Blowing in a cat’s face or gentle manipulation of the larynx to stop purring ↓ Sensitivity to 1/2 to ↓ the amplitude of the wave • Verify that the patient is in a comfortable position. • Hold the animal’s mouth shut for short periods to obtain each lead. CHAPTER 8 / PATIENT CARE 345 8 Skill Box 8.6 / Heat Administration Heat support is required for all animals unable to regulate their body temperature at the normal level (100.5–102.5° F). Anesthetized, severely ill, and/or physically compromised patients are unable to regulate their body temperature and routinely require additional methods of heat support. Hypothermia will significantly slow recovery and severe hypothermia can cause arrhythmias and coagulation problems; prevention is better than management. Alternatively, monitoring the patient who is on heat support is also important to ensure that they do not become overheated or incidentally burned. Hospitalized or anesthetized patients are often unable to move away from an external heat source and often have decreased peripheral blood supply, leading to sometimes severe and extensive thermal burns. Shivering increases oxygen demand by up to 400%; additional oxygen should be provided if a patient is cold and shivering. It is better not to have to warm patients in recovery (e.g., keep them warm under anesthesia). Warming devices should be used immediately; otherwise, cooling will continue. Bair huggers, incubators, IV fluid warmers, and circulating warm air blankets are ideal. Warmed IV fluid bags are not recommended as severe and extensive contact burns occur. Proper padding on all surfaces should be instituted to control heat loss to the undersurface. Rectal temperature is not core temperature but allows trends to be assessed and should be measured regularly to ensure a return to normothermia. Esophageal temperature probes may be reflective of core body temperature in anesthetized patients. Basic heat support that does not require additional equipment includes keeping the patient dry, keeping patients away from air vents and air conditioners, maintaining warm room temperatures, and providing insulation materials against surgery tables and cages. Along with providing heat support, it is also important to ensure heat retention. Many quick methods have been devised, such as wrapping the patient with bubble wrap, placing the patient on foam padding, and placing baby socks on the paws. 8 Method Use Comments Circulating Heated Water Blankets • Preheated circulating controlled warm water vinyl pad is placed under the patient. • Thermal burns may occur (rare). • Blankets or other protective coverings are placed on top of the pad to prevent inadvertent puncture. • Provide a minimal amount of heat support. Heated Air Blankets (Bair Huggers) • Blanket is placed over the patient. • Place a cotton blanket over the blanket or gown for maximum effectiveness. • Do not use over transdermal medication as ↑ drug delivery and subsequent overdose may occur. • Do not place blankets over the patient’s head as corneal drying may occur. • Use caution when using in surgery to avoid circulating contaminated air; do not turn on until patient is fully prepped and draped. Heated Bags • Expired IV fluid bags, rice or oat bags • Wrap the bag in a blanket or towel and place to the side of the patient. • Not recommended as severe thermal burns often occur • Bags should never be placed on top, underneath, or next to a shaved area of skin. • Remove bag once it has cooled to prevent reverse heat exchange. Hot Line IV Fluid Warmer • Fluids are warmed within the administration set using metal warming channels or multilumen circulating warm water. • Additional methods can be used alone or along with fluid warmers; running the fluid administration set through a bowl of hot water, placing a circulating heated water blanket around the line, coiling the line under the patient’s heat source. Warm Blankets and Towels • Blankets and towels warmed by a clothes dryer • Amount and length of heat are limited. 346 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.7 / Recumbent Patient Care Decubital sores (pressure sores), urine and fecal scalding, and lung atelectasis can be the source of further patient complications and can lead to ↑ morbidity and mortality. Recumbent patients with neurologic or orthopedic disease are at the greatest risk of acquiring these complications. Appropriate and observant nursing care should prevent or identify these complications in their early stages. Early identification will minimize the impact they place on the patient. Patients should be lifted and turned as dragging or pulling across the floor can lead to disruption in skin integrity and the beginning of decubital sores. Condition Cause Prevention Treatment Comments Decubital Sores • Excessive pressure, friction, or shearing forces over a bony prominence resulting in local or regional ischemia • Anatomical differences: thin breeds (↓ muscle or fat padding over bones), obese or large and giant breeds (excessive weight and pressure), thick hair coat (trapping of moisture and inability to monitor skin changes) • Underlying disease conditions: paralysis, inability or unwillingness to change position, malnutrition, impaired circulation, metabolic disease, thick hair coat • Identifying at-risk patients • Monitor daily for early signs (e.g., erythema, edema, tenderness, exudate, alopecia) • Adequate nutritional status • Beds (e.g., hammocks, air or water mattresses) • Bedding (e.g., orthopedic pads, thick blankets) • Keeping the patient’s skin clean and dry • Repositioning every 2–4 hours • Passive exercise and massage to circulation • Relieve pressure (e.g., “doughnuts,” inflatable rings). • Clip and clean with an antiseptic. • Drug administration (e.g., systemic antibiotics) • Debridement, surgical and wound management (See Chapter 10 Wound Care and Bandaging, page 395.) • Greater trochanter is the most common site, but additional pressure points of forelimbs and hindlimbs are also seen. • Obtain bacterial swabs prior to cleaning. Urine and Fecal Scalding • Exposure to urine or feces for extended periods of time or with compromised skin integrity • • • • Clean bedding Grates Beds (e.g., nylon mesh hammock) Protective topical ointments (e.g., petrolatum) applied to the perineal and inguinal areas • Bathing • Clip and clean with an antiseptic • Drug administration (e.g., silver sulfadine, systemic antibiotics) • Debridement, surgical and wound management (See Chapter 10 Wound Care and Bandaging, page 395.) • Patients with urinesoaked fur should assumed to have urinesoaked skin. • Can result in severe dermatitis and predispose to decubital ulcers Lung Atelectasis • Extended periods of one-sided recumbency • Repositioning every 2–4 hours • Reexpansion (e.g., repositioning, removal of air or fluid from pleural space) • Auscultation reveals localized areas of dullness. 8 CHAPTER 8 / PATIENT CARE 347 DRUG ADMINISTRATION Skill Box 8.8 / Injections Subcutaneous Injection (SQ) Intramuscular Injection (IM) Intravenous Injection (IV) Location • Typically between the scapulas, but could be anywhere the skin can provide a tent for injection • Lumbar region, semimembranous, and semitendinosus muscles • Any accessible vein (e.g., external jugular vein, cephalic vein, saphenous vein, pedal veins, lingual vein during anesthesia) Volume • Fluid administration: 50–100 mL in one location depending on the size and species of the animal • <3 mL per site • Large volumes can be administered. Technique • Gently pull an area of skin up to form a small “tent.” Insert the needle with the bevel side up at a 15° angle through the center of the “tent.” You should feel the needle pop through the skin. Aspirate for blood and then inject the contents intended. Rear Leg • Place the needle at least a thumb’s width from the femur. Inject the needle in a slightly caudal direction, aspirate for blood and inject the contents of the syringe. • Avoid: sciatic nerve, femoral artery and vein, popliteal lymph node and the femur Lumbar Region • Place your thumb on the wing of the ilium and your middle finger on a vertebra of the spine. Let your index finger fall naturally; where it lands is the location for the injection. Inject the needle straight into the muscle, aspirate for blood, and inject contents of syringe. • Avoid: all nerves and blood vessels Jugular Vein • Occlude the vein in the jugular furrow at the thoracic inlet with thumb of nonsyringe hand. The head should be slightly rotated toward the injection site for better visibility. The jugular vein typically lies in the cowlick of the fur running from the ramus of the mandible to the thoracic inlet. Insert the needle parallel to the skin in a cranial direction, aspirate for blood, either inject contents of syringe or withdraw blood. • Avoid: the carotid artery Peripheral Vein • Once vein is occluded by either a tourniquet or assistant, lay thumb alongside the vein to stabilize it. Insert the needle parallel to the skin in a cranial direction, aspirate for blood, either inject contents of syringe or withdraw blood. • Avoid: all nerves Tips • Changing needles before injection; use of a 25-gauge needle • Gently squeezing or flicking the injection site to dull the area • Distraction (e.g., treats, sliding the patient across the table or lifting their front legs, twitching a ear or tapping the nose, talking to the patient). • Pinching the injection site before administration desensitizes the area. • Changing to a 25-gauge needle also provides a less painful injection, because the new needle is not dull and is smaller. • Distract the animal while giving the injection. • Use EMLA on prepared skin to desensitize the animal’s reaction to insertion of the catheter. Place 1 g on shaved area, cover with dressing, and wait a minimum of 1 hour for full effect. • Gentle insertion of the needle typically results in much less of a reaction than thrusting. • Distract the animal while giving the injection. 8 348 SECTION FOUR: PATIENT CARE SKILLS Intravenous Catheter Placement Catheters are used in veterinary medicine to gain access to the vascular system for administration of medications or fluids as well as to obtain blood samples. The following section explains the various techniques and their care. Being able to place a catheter quickly is a valuable skill in a technician. Skill Box 8.9 / Intravenous Catheter Placement: Peripheral and Jugular Method IV Catheter, Peripheral IV Catheter, Jugular Indications • IV access for fluids, medications, and anesthesia • Central line placement is desired and a jugular vein is not available. • IV access for fluids, medications, and anesthesia • Patients with poor peripheral veins or circulation, CVP measurement or reliable blood sampling Contraindications • Burn, abrasion, or pyoderma over site, thrombosis of chosen vein, and infusion of hyperoncotic solutions (parenteral nutrition) • Burn, abrasion, or pyoderma over site, severe coagulopathy, hypercoagulable, or thrombosis of chosen vein Catheter Sites • Cephalic and saphenous veins • Pedal vein (contraindicated with hypertonic fluids) • External jugular vein and femoral vein Setup • Surgical site preparation materials • 1/2 and 1 inch tape • • • • Procedure Clip a wide area of hair leaving a 2″ border above and below the catheter insertion point. Wash hands and put on gloves. Apply Nolvasan from a yoker bottle and using cotton balls, wipe the skin gently. (Avoid vigorous scrubbing) Follow with an alcohol soaked cotton ball to wipe the area being sure not to introduce bacteria from the outer edges of the clipped site. Follow the above steps using Technicare. As the final prep, apply Technicare, but do not wipe off with alcohol. Change gloves. Perform a cut down if necessary with the tip of a sterile needle. Insert catheter SQ and then penetrate the vessel. Cap the catheter with a T-port and flush with saline and secure with tape. Additional bandaging may be placed in long term catheters, however less is typically more in this case. • • • • IV catheter Saline flush T-port 22-gauge needle Surgical site preparation materials Sterile gauze: 3X3 1 /2 and 1 inch tape IV catheter • • • • Saline flush T-port primed with saline 22-gauge needle Lidocaine 2% 8 Set up all required materials. Hold off the jugular vein and carefully clip the area of the insertion site, avoiding clipper burn. (If the animal is in sternal recumbency, the person who is placing the catheter holds off the vein; if the animal is in lateral recumbency, the restrainer holds off the vein.) Wash hands, put on gloves and follow scrub technique for peripheral catheter placement. Change to sterile gloves, tent the skin, place the needle under the skin near the vessel at a 30–45° angle. While maintaining the same catheter angle, palpate the vessel and advance only the tip of the catheter into the vein. A “pop” should be felt. A flashback is not seen in many jugular catheters until aspirated. Thread the catheter the rest of the way into the vein. If there is a needle guard, place the needle in the groove and clamp shut. Be sure the hub of the catheter is locked into the hub of the needle. Remove the stylet and attach the T-port. Aspirate and then flush with 3–6 mL heparinized saline. Place a butterfly tape around the catheter hub and secure the catheter. The needle guard can be used to suture the catheter in place, or a butterfly tape can be applied to provide more stability. Adhere the catheter to the skin with 3 simple interrupted nonabsorbable sutures (one on each side of the catheter and a third as an anchor). Place triple antibiotic ointment over the catheter entry site. Place a drop of glue to the catheter/ needle hub if applicable to the catheter type. Place a second strip of tape in a counterclockwise direction. Apply cast padding loosely around the animal’s neck clockwise and then counter clockwise, keeping the T-port clear. Apply the gauze wrap in the same manner. Flush T-port with heparinized saline, aspirate, and then flush again. Place a layer of elastic tape, testing the tightness by ensuring that 2 fingers can be inserted under the wrap. Place a piece of tape to secure the T-port and write the date of placement on it. Radiographs can be taken to assess proper placement. CHAPTER 8 / PATIENT CARE 349 Skill Box 8.9 / Intravenous Catheter Placement: Peripheral and Jugular (Continued) Method IV Catheter, Peripheral IV Catheter, Jugular Complications • Phlebitis, nonpatent, and FUO • Phlebitis, nonpatent, FUO, facial and front limb edema Removal • Remove after 72 hours. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A cotton ball and Vet-Wrap bandage is placed for 1–2 hours • Remove after 72 hours. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A cotton ball and Vet-Wrap bandage is placed for 1–2 hours Tip: The right external jugular maintains a straighter course and is often preferred for jugular placement. Skill Box 8.10 / Intravenous Catheter Placement: Arterial and Intraosseous 8 Method IV Catheter, Arterial IV Catheter, Intraosseous Indications • Blood gas analysis, continuous blood pressure monitoring, blood sampling • CVP fluid administration Contraindications • Drug or fluid administration • Burn, abrasion, or pyoderma over site • Thromboembolic disease, hypercoagulopathy, and ambulatory patients • Osteopenia or infected tissue over the site Catheter Sites • Dorsal pedal, femoral, and auricular arteries • Greater trochanter of the proximal femur, flat medial aspect of the proximal tibia (in obese animals), and greater tubercle of the humerus Setup • • • • • • • • • • • • 350 Surgical site preparation materials /2- and 1-inch tape IV catheter Saline flush T-port 22-gauge needle 1 SECTION FOUR: PATIENT CARE SKILLS Surgical site preparation materials Sterile gauze: 3 × 3 inches 1 /2- and 1-inch tape IV catheter Saline flush T-port primed with saline • • • • • • 22-gauge needle Lidocaine 2% No. 15 or No. 11 scalpel blade 16-gauge bone marrow needle Suture material Triple antibiotic ointment Skill Box 8.10 / Intravenous Catheter Placement: Arterial and Intraosseous (Continued) Method IV Catheter, Arterial IV Catheter, Intraosseous Procedure Follow peripheral catheter protocol. Place a gauze square just below the insertion site to help maintain an aseptic area as well as absorb any blood. Using a smooth and steady technique, insert the catheter with bevel side facing up into the artery at a 30–45° angle. A flashback of blood is seen upon entering the artery. Palpate the pulse and then advance the catheter toward the strongest area of pulse; withdraw the needle stylet. Blood should be seen at the hub of the catheter. Cap the catheter with a T-port and flush with saline and secure with tape. Label the catheter as arterial. Set up all required materials. Clip the greater trochanter and scrub with chlorhexidine soaked gauze, using aseptic technique. Inject a bupivacaine or lidocaine subcutaneously if the animal is responsive (0.1 mL at the catheter insertion site). Place a sterile gauze square just below the insertion site to help maintain an aseptic area as well as absorb any blood. Incise the insertion site with a No. 15 or No. 11 scalpel blade. Using sterile technique and the leg in adduction, place one hand along the side of the femur with the thumb pointing toward the greater trochanter. Pass the catheter through the insertion site, down the medial aspect of the greater trochanter, and into the trochanteric fossa. Push the catheter through the cortex by applying downward pressure and rotating a quarter turn with each rotation. A loss of resistance is felt when the catheter passes through the cortex. The catheter will bounce lightly down the bone. Verify placement by aspirating and observing for bone marrow particulates and by rotating the femur; the catheter and femur should move as one. Remove cap and stylet and attach fluid set. Secure into place by suturing tape attached to the catheter to the skin. Secure in place with bandage material. Complications • Venous puncture, phlebitis, nonpatent, and FUO • Osteomyelitis, fractures, growth plate damage, and displacement Removal • Remove after 3–5 days. • Tape is cut with bandage scissors and catheter is slowly pulled out. • A pressure wrap is placed for 10 minutes, followed by a cotton ball and Vet-Wrap bandage for 1–2 hours. • Remove after 3–5 days. • Tape is cut with bandage scissors and catheter is slowly pulled out. 8 Tip: Use EMLA on prepared skin to desensitize the animal’s reaction to insertion of the catheter. Place 1 g on shaved area, cover with dressing, and wait a minimum of 1 hour for full effect. Tip: Securely attach the tape to the catheter by making a tape butterfly. Leave approximately 1 inch of tape on either side of the catheter and then loop the tape back onto itself such that there is a 1-inch “wing” on either side of the catheter. Use these wings to suture the catheter in or as an additional spot of contact when taping around the circumference of the limb of the patient. Skill Box 8.11 / Intravenous Catheter Monitoring and Maintenance Patient Care Equipment Care • Monitor for signs of fever, lethargy, or changes in vital signs in the animal (which may represent sepsis). • Swab injection ports on catheter and fluid bags with an antimicrobial solution prior to each injection. Catheter Care • Replace T-ports and administration sets every 24 hours or sooner with obvious wear or contamination, especially in critically ill and immunosuppressed patients. • Flush catheter every 4–6 hours with saline to assess patency and patient response. • Remove bandaging every 24 hours to observe for phlebitis, swelling, redness, pain, hot to the touch and displacement. • Replace catheters every 3–5 days or sooner if warranted. • Replace bandaging every 24 hours, when soiled or wet. • Observe strict aseptic technique when changing administration sets and fluid bags. Note: In discontinuing fluid therapy, fluids should not be stopped abruptly, especially with patients receiving high flow rates. Slowly weaning the patient off fluids over 24 hours allows the kidneys to adjust and again concentrate urine well, to avoid continuous excessive fluid loss. CHAPTER 8 / PATIENT CARE 351 Chemotherapy As the number of clinics providing chemotherapy administration increases, it is important for the safety of the person administrating, the owner, and the patient to have the appropriate safety information available. Proper training is essential as these drugs are considered potentially hazardous. Routes of exposure include absorption, inhalation, and ingestion. Each clinic should have documented preparation, storage, and disposal protocols for the various agents. Chemotherapy administration should take place in a well-ventilated, low-traffic area of the hospital. Skill Box 8.12 / Chemotherapy: Administration Steps Preparation 1. Drug Calculation • Review the patient’s record, and recheck the chemotherapy protocol and drug calculations. • It is best to have a second person confirm the drug calculations. Note: Chemotherapy drugs differ as to their body weight calculations (e.g., kilograms, pounds, or square meters): be sure to verify the correct form. Also, most drugs are based on lean body weight, not actual body weight. 2. Personnel Supplies Prepare yourself and assistant with safety gear regardless of administration technique: • Latex gloves: high-risk gloves or 2 pairs regular gloves Tip: With 2-pair system, wear 1 pair under the cuff of gown and 1 pair over the cuff of the gown. • Full face shield or protective eyewear • Mask: dust or mist respirator or a mask with a filter 8 Note: Surgical masks do not have a filter and are not sufficient. • Gown: disposable with long sleeves, closed front, and cuffs 3. Administration Supplies Oral • Chemotherapy agent • Hemostat or pill-gun 4. Drug Preparation 1. 2. 3. 4. 5. 6. 7. 8. 9. SQ/IM • Alcohol-soaked gauze sponges • Chemo-pin • Drop cloth with plastic backing • Chemotherapy agent • Gauze sponges • Syringe IV Same as above and along with • Catheter • Clippers • Scrub preparation materials • Tape Preparation in a well-ventilated area. Remove plastic cover of vial, and wipe the top with an alcohol swab. Insert the chemo-pin into the vial. Attach syringe to the chemo-pin while holding the vial upright. If adding a diluent, add slowly and then mix contents of vial completely, with the Luer-Loc syringe left in place. Turn vial upside down and aspirate drug into syringe slowly to avoid excess air bubbles. Push any excess air back into the syringe before separating from vial. Wrap gauze around the connection between the syringe and vial and gently pull apart. Place a covered needle onto the syringe. Tip: Do not inject air into the vial; maintaining a negative pressure within the vial reduces the risk of aerosolization. • When not using a chemo-pin, all the above steps are accomplished with a needle attached to the end of a Luer-Lok syringe. • Do not fill a syringe more than 2/3 full, to prevent the plunger from detaching from the syringe. • If an agent is to be administered via a fluid bag, fill the administration set with plain diluent before adding the chemotherapy agent to reduce the risk of contamination when attaching the line to the patient. 352 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.12 / Chemotherapy: Administration (Continued) Steps Preparation 5. Patient Preparation 1. 2. 3. 4. 6. Drug Administration 1. With an alcohol-soaked gauze around the end of the catheter, insert the needle into the catheter and administer the drug at the correct rate but at an even pace to avoid leakage around venipuncture site. 2. Flush the catheter with 3–5 mL nonheparinized 0.9% sodium chloride after administration to avoid irritation to the vein. 3. Monitor for allergic reactions for up to 1 hour after administration of certain drugs (e.g., L-asparginase). 4. Apply a pressure wrap after removing the catheter, and maintain pressure for several minutes. • Place an alcohol-soaked gauze sponge over the injection site whenever inserting or removing the needle or catheter to avoid aerosolization of the drug. • Do not aspirate the drug back into the catheter after administration to avoid dilution and residual drug in the catheter injection port. 7. Disposal 1. Place all items in a zip-lock bag to prevent aerosolization. 2. Dispose of the waste into an appropriate biohazard container. 3. Clean the preparation and administration surfaces thoroughly. Select vein: peripheral veins are recommended because they provide better visualization of any drug that becomes extravascular. Aseptically clip and prepare the site. Place a catheter: butterfly, over-the-needle, or through-the-needle intracatheter. Ensure patency of the catheter by flushing at least 12 mL nonheparinized 0.9% sodium chloride. • Once a vein has been unsuccessfully punctured, a new vein should be used. If this is not possible, it is recommended that time be allowed for the proper clotting to occur before a proximal site is used. • Heparinized saline should not be used as it may cause the drug to form a precipitate. 8 Tip: Before removing gloves, place capped syringes and any other used products that may aerosolize into your hands, pull gloves off over the materials, and then dispose of them. 8. Post Patient Care 1. Wear double layer of gloves when handling waste from the patient for the first 72 hours. 2. Wipe down cages as using a hose or spray may aerosolize excreted drugs. 3. Closely monitor response to drug (e.g., attitude, appetite, eliminations, and general behavior). Table 8.7 / Chemotherapy: Toxicity Chemotherapy is the process of administering drugs to attack actively growing and dividing tumor cells. Unfortunately, these agents are not selective for tumor cells and will also attack other cells (e.g., bone marrow cells, gastrointestinal cells). With the administration of any chemotherapy agent, the patient must be monitored for adverse reactions and toxicities. Toxicities may not appear for several days following administration or until an accumulation of toxic levels have been obtained within the body. Most protocols are generally designed to result in <5% hospitalization rate (e.g., sepsis) for chemotherapy toxicity and <1% direct mortality rate from any particular toxicity. CHAPTER 8 / PATIENT CARE 353 Table 8.7 / Chemotherapy: Toxicity Treatment Comments • Neutropenia • Anemia, thrombocytopenia (rare) Neutropenia • <1000–2000/μL • ↓ Dose by 10–25% • <1500/μL • ↓ Dose by 10–25% • Drug administration (e.g., trimethoprim-sulfa, fluoroquinolones) • Monitor temperature. Neutropenia and fever • Hospitalization, IV fluids, antibiotics, blood work, blood culture, urinalysis and culture, thoracic radiographs, ± colony-stimulating factors Thrombocytopenia • Delay administration when platelet counts are <50,000–100,000/μL • CBC and platelet count are required 12–24 hours before all chemotherapy agents known to cause myelosuppresive (e.g., cisplatin, carboplatin, doxorubicin). • Severely neutropenic patients may not be able to show signs of infection or fever. • Nadir is typically seen 5–10 days after administration. • Delay of chemotherapy for 1 week typically allows for bone marrow recovery. • Arrhythmias • Acute, rare, transient • Cardiomyopathy • Chronic, cumulative Prevention • Drug administration with iron-chelating cardioprotective agents (e.g., dexrazoxane) • Drug infusion over 15 minutes or a CRI over several hours • ECG monitoring Treatment • Discontinue drug use if rhythm abnormalities are seen. • Drug administration (e.g., antiarrhythmics) • Mostly seen with canine doxorubicin administration • Limit total cumulative dose to <180 mg/m2 as a guideline for doxorubicin. • Cardiotoxicity is almost always irreversible and fatal. • Alopecia, delayed hair regrowth, hyperpigmentation, hair color alterations • No treatment necessary • Mostly seen in nonshedding breeds (e.g., Poodle, Terriers, Old English Sheepdog). • Regrowth seen soon after discontinuing chemotherapy. • Change in color or textures may be initially seen, but often resolves with time. • Local tissue necrosis • Secondary to extravasated agent Prevention • Meticulous catheter placement and monitoring Treatment • Discontinue infusion. • Do not remove needle; withdraw as much of the drug as possible. • Inject 10–20 mL of sterile saline and dexamethasone (1–4 mg) into the area of extravasation. • Vincristine: • Instill 1 mL of hyaluronidase (150 units/mL) for every mL extravasated. • Apply warm packs for 24–48 hours to site. • Doxorubicin: • Instill 10 times the amount of DHM3 or dexrazoxane IV for the amount extravasated and SQ at the site of extravasation. • Apply cold packs for 6–10 hours to site. • Cisplatin • Instill 1 mL of isotonic sodium thiosulfate for every mL extravasated. • Mostly seen with vincristine, doxorubicin, and cisplatin. • Sloughs typically appear at 7–10 days and should be treated as an open wound. • Bandages and E-collars can be used to avoid additional self-trauma. • ± Use of topical DMSO and infiltrated hydrocortisone (doxorubicin and vincristine) • Warn of potential for limb amputation if severe necrosis. Cardiac Hematologic Complication Dermatologic 8 354 SECTION FOUR: PATIENT CARE SKILLS Comments • Nausea, inappetence, vomiting, diarrhea, enterocolitis • Symptomatic therapy (e.g., highly palatable food, appetite stimulants, antiemetics, motility modifiers) • Severe: • IV fluids • Nutritional support • Antibiotic therapy • Preemptive antiemetics (e.g., odansetron) • Mostly mild and self-limiting, except cisplatin, which can be severely emetogenic • Typically occur 5–7 days post administration Hypersensitivity Complication • Urticaria, erythema, restlessness, head shaking, vomiting • Cardiovascular collapse (canine, rare), anaphylaxis • Respiratory distress (feline) Prevention • Drug administration (e.g., diphenhydramine, dexamethasone) Treatment • Slowing or discontinuing drug infusion in hypersensitive patients • IV fluids • Drug administration (e.g., dexamethasone, epinephrine) preemptively or during symptoms • Mostly seen with doxorubicin and L-asparaginase administration • Cerebellar ataxia • Peripheral neuropathy (e.g., constipation, hyporeflexia, weakness, motor dysfunction) Peripheral neuropathy • Bulk laxatives • Remain within guidelines of dosages (e.g., 5-FU < 20 mg/kg PO) • Mostly seen with 5-FU (cerebellar ataxia) and vincristine (peripheral neuropathy) • Nephrotoxicity • IV fluid diuresis (pre and post) • Monitor serum creatinine and urine specific gravity • Mostly seen with cisplatin (canine) and doxorubicin (feline) • Avoid use in canines with existing renal insufficiency. • Hemorrhagic cystitis • Stranguria, pollakiuria, hematuria Prevention • Altering dosing frequency or drug choice • Administer in the morning to allow more time to empty bladder. • Drug administration (e.g., furosemide) • IV diuresis around time of injection • Provide access to fresh water and frequent trips outside. Treatment • Drug administration (e.g., NSAIDs, DMSO, 1% formalin) • Mostly seen with canine cyclophosphamide administration • Do not repeat if cystitis occurs. • Mild cases are often self-limiting. • Acute collapse and shock • Aggressive fluid therapy • Labwork monitoring • Rare condition • Extensive treatment for lymphoma or leukemia with rapid tumor breakdown Acute Tumor Lysis Syndrome Urologic Gastrointestinal Treatment Neurologic Table 8.7 / Chemotherapy: Toxicity (Continued) 8 CHAPTER 8 / PATIENT CARE 355 Skill Box 8.13 / Client Education: Monitoring Chemotherapy Response Patients receiving chemotherapy should be closely monitored by their owners to evaluate their response to treatment. Often clients are overly concerned about the health of the animal and therefore should be given guidelines as to when to call the clinic and when to monitor at home. Educating the client can give them the information and tools to make basic care decisions at home. Clinical Signs 8 When to Call Monitor Call Clinic Appetite • Picky, but still eats treats • Inappetance Attitude • Slightly lethargic • Lethargic and/or reluctant to move Bowel movements • Soft stool • Diarrhea Temperature • ≤103° F • >103° F Urination • Normal • Bloody urine Vomiting • Single event • Frequent and retching • Wear double-layer gloves when cleaning up urine, feces, or vomitus for 48 hours after receiving chemotherapy and follow proper disposal guidelines. • Maintain a low-stress environment. • Ensure proper scheduling of the next chemotherapy administration and follow-up evaluations and lab work. 356 SECTION FOUR: PATIENT CARE SKILLS Insulin Therapy Skill Box 8.14 / Client Education: Insulin Administration Not all insulin syringes are alike, which can lead to incorrect dosage of insulin. Insulin syringes are typically found in 100-unit and 30-unit sizes. The 100-unit syringes are numbered in 10s with the smallest lines each measuring 2 units of insulin. The 30-unit syringes are numbered in 5s with the smallest line each measuring 1 unit of insulin. When administering small amounts of insulin it is advisable to use 30 unit syringes so as to ensure accuracy. Care must be taken to verify the type of syringe after purchase and before administration. Variations can also exist in the concentration of insulin; Vetsulin and PZI are U-40 with each 1 mL containing 40 units of insulin, while Glargine and Humulin R and U are U-100, with each 1 mL containing 100 units of insulin. Not being aware of this difference can greatly overdose or underdose a patient. Preparation Drawing Up the Medication Administering the Insulin • See Table 17.30 Metabolic Drugs: Pancreatic, page 600. • Do not shake the vial; gently roll it between the palm of your hands to mix. • Use a new syringe for each injection. 1. Pull back the plunger of the syringe to position the top of the plunger (part closest to the needle) at the desired dose. 2. Insert the needle into the vial, and inject the air to prevent a vacuum in the vial. 3. Slowly pull back on the plunger to the desired amount and withdraw the needle from the vial. 4. Check to make sure there are no bubbles in the syringe; if present, pull back on the plunger, and tap the syringe to move the bubbles to the top. Then push the plunger until all the air is out of the syringe. 5. Verify the correct amount of insulin is within the syringe. 1. Locate an area anywhere from mid neck to the last rib and halfway down on either side, changing with each injection. 2. Place your index finger against the back of the animal and use your thumb and middle finger to pull up skin to form a “tent” under your index finger. 3. Insert the needle, bevel side up, into the skin at a 45° angle. 4. Pull back on the plunger to verify no blood or air fills the syringe; if present, remove needle and try again. 5. Depress the plunger to insert the insulin under the skin. 6. Remove the syringe and immediately recap it. 7. Properly dispose of the syringe and needle. CHAPTER 8 / PATIENT CARE 357 8 Skill Box 8.15 / Client Education: Monitoring Insulin Response When caring for a diabetic patient, diligent monitoring both at home and along with careful veterinary management must take place to achieve the appropriate patient plan. Along with monitoring for life-threatening hypoglycemia, hyperglycemia must also be monitored to evaluate the patient’s response to insulin and to detect any early complications. With the initiation of insulin therapy, the protocol will vary until the patient has become regulated. To monitor long-term insulin therapy with veterinary management, physical examinations are scheduled every 2–6 months and serum fructosamine or glycosylated hemoglobin concentrations are obtained. The success of the treatment of most diabetic patients lies in the hands of the owner, their attention to detail and keen observations are critical. At home monitoring includes the parameters listed below; all results should be relayed to the veterinarian so adequate dose adjustments can be made. 8 • Monitor • Appetite • Attitude • Body condition • Polydipsia/polyuria • Urine glucose/ketone levels • Initially, monitor daily and then 2–4 times monthly. • Urine glucose should maintain 0–1+. • Consistent high results (>2+) may require ↑ dose and consistently low results (0) may require ↓ dose as directed by veterinarian. • Positive results may be seen with excitement, ↑ carbohydrate intake and corticosteroid administration. • See Tips under Urogenital Procedures for collecting urine samples at home, page 434. • Glucometer • Fasting blood glucose (BG) twice weekly and blood glucose curve monthly or as directed by veterinarian • BGC • Necessary to assess insulin efficacy, peak and duration of effect, and degree of fluctuations • At home monitoring: • Test every 2 hours (every 4 hours with Glargine) starting before the morning insulin and ending after the following morning insulin dose. • Ideal BGC results show the nadir (lowest BG) between 100–150 mg/dL halfway between dosing intervals. • A variety of glucometers are available for home monitoring. • Blood samples are obtained from the capillary bed of the ear margin, foot pads, and (canine only) lip, elbow callus, and base of tail. 358 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.16 / Client Education: Monitoring for Hypoglycemia Hypoglycemia is the condition of a low blood glucose level, too low to effectively fuel the body’s blood cells. This is often seen when there is a relative or absolute excess of insulin circulating in the bloodstream caused by; too much insulin administered, missed or delayed meal, eating a smaller than normal meal, vomiting a meal, strenuous exercise, stress and certain medications. With a blood glucose level <60 mg/dL, most animals will exhibit a drunken state and the administration of a carbohydrate source will show a quick recovery. Animals with a blood glucose level <20 mg/dL often lose consciousness and seizures may occur; the administration of a carbohydrate source should be immediately instituted followed by immediate medical attention. Signs to Watch for Actions to Take Prevention • • • • • • • Give a carbohydrate source orally (e.g., Karo syrup, maple syrup). • Seek veterinary care immediately. • Keep the animal warm. • Feed the animal the same food and amount at the same times every day. • Do not feed table scraps or any diet other than the agreed-on diabetic diet. • Feed multiple meals each day. • Provide fresh clean water at all times. • Maintain a consistent exercise program. • Do not administer insulin to a patient that is not eating unless directed to do so by the veterinarian. Depression, lethargy Deviations from normal behavior Drunken state (e.g., stumbling, staggering) Lack of appetite Panting Seizures, comas 8 FLUID THERAPY Fluid administration is necessary when an animal is dehydrated, experiencing shock, losing blood, or having a surgical procedure that may result in excessive blood loss or has a disease that is resulting in depletion of the animal’s normal fluid, electrolyte, or acid-base balances. Dehydration may lead to hypovolemia and hypoperfusion. Fluid requirements are based on an animal’s hydration status, reason for fluid loss, and physical condition. The veterinarian is responsible for prescribing the appropriate fluid therapy. Obtaining the following assessments will assist the veterinarian in the calculation of fluid requirements for the animal. Distinction between dehydration and perfusion status is an important factor in the veterinarian’s choice of fluid therapy. The following charts are to provide the technician with information to help understand the veterinarian’s fluid therapy plan and to assist in the process of administration. CHAPTER 8 / PATIENT CARE 359 Skill Box 8.17 / Hydration Assessment Physical Examination Assessment of Hydration Medical History Laboratory Assessment 8 360 Hydration Significance Assess Dehydration Status • Skin turgor: assess the amount of time it takes for the skin to return to the animal’s body when gently pulled up and twisted at the back of the neck or along the spine. Use 2 or 3 assessment locations. • Obesity can falsely ↓ turgor, and emaciation can falsely ↑ turgor. • Mucous membranes: assess for dryness of gums and cornea (moist, tacky, dry) • Eye position: assess the degree of eye sinkage into the bony orbit Assess Perfusion Status • Capillary refill time: direct digital pressure is applied to the mucous membranes until blanched and then timed for blood (pink color) to return (normal: <1–2 seconds) • Heart rate and pulse (femoral and metatarsal): assess heart rate, pulse (amplitude and duration) • Canine: 70–180 bpm • Feline: 110–220 bpm • Weight of the animal: Patient’s normal body weight and current weight should be noted. 1 lb. body weight = 1 pint (480 mL) fluid <5%: normal hydration • No obvious clinical sign • Skin turgor: <2 seconds 6%–8%: mild dehydration • Skin: Inelastic and leathery • Twist: disappears immediately • Skin turgor: >3 seconds • Eyes: duller than normal and sunken • Mucous membranes: tacky to dry 8%–10%: moderate dehydration • Skin: inelastic and leathery • Twist: disappears slowly • Skin turgor: >3 seconds • Eyes: duller than normal and sunken • Mucous membranes: tacky to dry • Heart rate: ↑ 10%–12%: severe dehydration • Skin: no elasticity • Twist: remains indefinitely • Skin turgor: remains indefinitely • Eyes: dry, deeply sunken • Mucous membranes: dry, cyanotic, and possibly cold • CRT: prolonged or absent • Heart rate: ↑ • Pulse: weak 12%–15%: patient is in shock and death is imminent Packed cell volume • Canine: 37%–55% • Feline: 24%–45% • Dehydration at >45% Total protein, serum • Canine: 5.4–7.6 g/dL • Feline: 6.0–8.1 g/dL • Dehydration at >8.0 g/dL Urine specific gravity • Canine: >1.035 • Feline: >1.040 • Evaluates kidney function more than hydration status, only reflects dehydration if kidneys are healthy. CVP • <8 cm H2O • Monitor trends over time, not a single reading • See Skill Box 8.2 Central Venous Pressure, page 334. • Assesses true venous return to the heart • Low pressure reflects low effective circulating volume. Serum lactate • ↑ Serum lactate may indicate poor perfusion. Patient’s history Fluid Loss • Amount of vomiting, diarrhea, and salivation • Amount of fluid and food intake Review of patient’s file • Previous physical problems (e.g., heart disease, kidney diseases) will influence fluid therapy SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.18 / Calculating Fluid Requirements The rates shown below are for those patients without pulmonary, cardiac or severe renal disease and are able to handle total rapid or high fluid rates. Veterinarians will need to prescribe the actual amount, the type of, and the rate of the fluid to be administered. Purpose Basis of Calculations Rate Rehydration Basic Rehydration Formula • Calculates the fixed rate of replacement fluids to correct the deficit over 4–6 hours • % dehydrated × body weight (kg) × 1000 mL/kg = mL of fluid replacement Example: Animal weighing 20 kg is dehydrated 6%. Fluid needed for basic rehydration is calculated as: 0.06 × 20 (kg) × 1000 (mL/kg) = 1,200 mL Maintenance Calculation • Calculates the amount of fluid to replace losses resulting from urination, feces, respiration • Panting and fever will ↑ amount of fluid loss (evaporative loss). • 40–60 mL/kg/day in a mature animal • Dependent on the cause of the loss and animal’s condition Ongoing losses • Calculates the amount of fluid loss attributable to excessive vomiting, diarrhea, polyuria, and third spacing of body fluids • 20 mL vomit = 20 mL fluids Anesthetic Protocol • Calculated on expected fluid loss during surgery (e.g., blood) • Healthy patients, elective procedures: 5 mL/kg/hr • 5–15 mL/kg/hr • Adjustments made based on patient’s status (e.g., blood pressure, perfusion) Postoperative Protocol • Calculated to account for rehydration, maintenance, and ongoing losses • Evaluation rehydration above Pediatric Protocol • Calculated to account for the rapid water turnover of neonates as their body weight is 80% water • 60–180 mL/kg/day Shock Protocol • Calculated to establish a circulating blood volume to allow adequate tissue perfusion • Crystalloids • Canine: 40–90 mL/kg/hr • Feline: 20–60 mL/kg/hr • Colloids • Canine: 15–20 mL/kg, increments of 5 mL/kg over 15 minutes • Feline: 25 mL/kg/day, administered over 30–40 minutes • Rates are adjusted when crystalloids and colloids are given concurrently. • Rates are indicated when the patient has adequate/normal cardiopulmonary function. CHAPTER 8 / PATIENT CARE 8 361 Table 8.8 / Routes of Fluid Administration Route Indication Complications Notes Oral • Minimal fluid loss • Recent anorexia, neonates • Tracheal intubation and aspiration, vomiting, regurgitation, aerophagia • Contraindicated: vomiting, diarrhea, dysphagia, or life-threatening situations (e.g., shock) • Administration by bottle, syringe, or enteral feeding tubes Subcutaneous Dorsal Midline Dorsal Flanks • Mild to moderate dehydration • Maintenance • Injection site infection (rare) • Do not use >2.5 % dextrose, as sloughing and abscesses may occur • Contraindicated: infected or devitalized skin, hypothermia, or severely dehydrated • Warmed to body temperature and allow flow by gravity • Use only isotonic fluids. • Use several sites; no more than 10–20 mL/kg. • Absorption is expected within 6–8 hours. • Technique: See Skill Box 8.8 Injections, page 348. Intravenous • Severe dehydration • Condition of animal is severe • Perioperative precaution • Phlebitis, septicemia, embolism, volume overload • • • • • Intraperitoneal • Mild to moderated dehydration • Large volumes • Peritonitis and intraabdominal abscess • Contraindicated: ascites, peritonitis, sepsis, pancreatitis, or expected abdominal surgery • Warmed to body temperature isotonic fluids • Absorption can take up to 20 minutes. • Used to treat severe hyper- or hypothermia • Technique: the caudal abdomen is aseptically prepared. An 18–22 gauge needle is inserted on the ventral midline, caudal to the umbilicus. The syringe is aspirated, if no fluid is seen (e.g., blood) the fluids are attached and administered. If fluid is seen, the needle is removed and repositioned. Intraosseous • Small animals (<5 kg), neonates, or animals with poor venous access • Osteomyelitis, fractures, and growth plate damage • Flush catheter with heparinized saline every 4–6 hours if fluid therapy is discontinued. • An IV catheter should be placed as soon as a site allows (24–72 hours). • All intravenous medications and fluids can be administered IO. • Technique: See Skill Box 8.10 Intravenous Catheter Placement: Arterial and Intraosseous, page 350. 8 362 SECTION FOUR: PATIENT CARE SKILLS Contraindicated: anemia Warmed to body temperature Requires rate calculation Requires closer monitoring; especially in cardiac insufficiency cases Flush catheter with heparinized saline every 6–12 hours; replace catheter every 72 hours. • Technique: See Skill Box 8.9 Intravenous Catheter Placement: Peripheral and Jugular, page 349. Table 8.9 / Commonly Used Fluids Selecting the type of fluid to administer can be as important as the selected route and rate. In selecting a fluid, it is important to know the electrolyte status of the patient and the underlying disease. From this information, fluids are then chosen based on a composition that best fits the patient’s condition and need. Colloids are most commonly used in shock, severe hypoalbuminemia, sepsis, SIRS, and hypotension, as they replace intravascular fluids. Due to the large-molecular-weight substances, colloids remain in the plasma compartment, leading to volume expansion. Synthetic colloids are chosen when the albumin is >2 g/dL; patients with albumin <2 g/dL require natural colloids (e.g., plasma, pRBCs). Crystalloids are the most commonly used extracellular replacement fluid, due to reduced expense, availability, and rapid rate of correcting volume deficits. Crystalloids contain electrolyte and nonelectrolyte solutes and are able to enter all body fluid compartments. However, only 20–33% remains in the vascular space 30 minutes and 10–20% 1 hour after administration. Synthetic Colloids Fluid Type Indications Route Comments Dextran 70 • Volume expansion • Shock therapy IV slowly • Monitor cardiac function. • Allergic responses (rare) • Possible coagulopathies, ↑ BG levels, altered TP and blood crossmatching results • Remains within the vascular space for 4–8 hours Hetastarch • Hypoproteinemia • Shock therapy IV • • • • • Volume expansion • Anemia and shock due to tissue hypoxia IV Oxyglobin Allergic responses, mostly cats, and eliminated with slow infusion Possible coagulopathies and ↑ amylase Remains within the vascular space for 12–48 hours ↑ Osmotic and oncotic pressure of blood 8 • Oxygen-carrying capacity for up to 40 hours • Altered serum chemistries and bilirubinuria • Slow infusion and diligent monitoring required to avoid fluid overload in normovolemic patients. • Used within 24 hours after removing the foil packaging • Indicated for dogs only CHAPTER 8 / PATIENT CARE 363 Table 8.9 / Commonly Used Fluids (Continued) 8 Crystalloids Fluid Type 364 Indications Route Comments Dextrose 5% in Water (D5W) • Isotonic • Free water deficits • Calories (179 kcal/L) • Hypernatremia IV • High dosages or prolonged use may produce pulmonary edema and dilution of electrolytes • Incompatible with penicillins Lactated Ringer’s • Isotonic • • • • IV, SQ • Contraindicated: hepatic disease, hypercalcemia, hyperkalemic, hyperlactatemic • Incompatible with cephalothin sodium and chlortetracycline Normosol-R • Isotonic • Replacement fluid • Maintenance fluid • Acidotic states IV, SQ • Contraindicated: cancer, hypercalcemia, hyperkalemic • May sting when given SQ Plasma-Lyte A • Isotonic • • • • IV, SQ • Contraindicated: hyperlactatemic, hypercalcemia, hyperkalemic • May sting when given SQ Ringer’s Solution • Isotonic • Replacement fluid • Corrects metabolic alkalosis IV, SQ, IP • Monitor: electrolyte concentrations and pulmonary function 0.45% Sodium Chloride (NaCl) • Hypotonic • • • • IV • Contraindicated: shock therapy • Used for patients with high risk of fluid retention 0.9% Sodium Chloride (NaCl) • Isotonic • Replacement fluid • ↑ Plasma volume • Hyponatremia, hypochloremia, hyperkalemia, hypercalcemia • Bathes tissue during surgical procedures • Shock therapy IV, SQ, IP • Contraindicated: sodium restricted cases, heart failure, hypertension, metabolic acidosis • Monitor: electrolyte concentrations and pulmonary pressure • Long-term infusion may cause electrolyte imbalances • Incompatible with amphotericin B 7.5% Sodium Chloride (NaCl) • Hypertonic • Volume expansion • Shock therapy IV • Normal hydration required before use • Administered in small boluses (e.g., 3–5 mL/kg) • Monitor: CVP, electrolytes SECTION FOUR: PATIENT CARE SKILLS Replacement fluid Maintenance fluid (short term) Acidotic states Shock therapy Replacement fluid Maintenance fluids Acidotic states Shock therapy Long term fluid therapy Free water deficits Hypernatremia Sodium restrictions Table 8.10 / Fluid Additives Additive Indications Route Comments Calcium Gluconate and Calcium Chloride • Correction of hypocalcemia • Eclampsia IV slowly • Contraindicated: hypercalcemia and ventricular fibrillation • Rate is variable depending on condition and other laboratory values. • Monitor: hypercalcemia, hypotension, cardiac arrhythmias (when given in conjunction with potassium), cardiac arrest and venous irritation • Calcium gluconate compatible with D5W, NaCl, LRS, dextrose/NaCl combinations and dextrose/LRS combinations Dextrose 50% • Hypoglycemia • Caloric supplementation IV • Contraindicated: hyperglycemia • See Skill Box 17.1 Basic Calculations, page 570. Potassium Chloride (KCl) • Prevention or correction of hypokalemia SQ, IM • Contraindicated: hyperkalemia, acute renal failure, acute dehydration and severe hemolytic reactions • Rate of infusion is critical: • IV: ≤0.5 mEq/kg/hr, do not exceed 40 mEq/L • SQ: ≤30 mEq/L • Must be diluted • Monitor: hyperkalemia, bradycardia, or arrhythmias • Compatible with all commonly used IV fluids • Acidosis may show falsely ↑ K+ levels and alkalosis falsely ↓ K+ levels. • Protect fluid bag from light. Sodium Bicarbonate • Correction of metabolic acidosis • Hypercalcemic and hyperkalemic crises IV • • • • • Vitamin B Complex • Anorexic patients SQ, IM, IV • Necessary for sufficient energy metabolism (e.g., glucose, fat, protein) • Protect fluid bag from light. Contraindicated: metabolic or respiratory alkalosis, hypochloremia and LRS fluids Caution: congestive heart failure or other edema-causing conditions Rate is variable depending on condition and other laboratory values. Monitor: blood gas measurements and acidosis status Compatible with D5W, NaCl, dextrose/NaCl combinations Skill Box 8.19 / Calculating Drip Rates 1. Number of mL needed/Time in which the fluid can be administered (in minutes) = mL/min Example: Need 1200 mL to be given over 5 hours, using a 15 drops/mL administration set: 2. mL/min × drops/mL of the administration set = No. of drops/min [1200 divided by (5 hours multiplied by 60 min/hr)] multiplied by 15 drops/mL = 60 drops/min or 1 drop/sec 3. No. of drops/min divided by 6 = No. of drops/10 seconds or No. of drops/min divided by 60 = No. of drops/second if the flow rate is high [1200/300] × 15 = 60 drops/min or 1 drop/sec CHAPTER 8 / PATIENT CARE 365 8 Table 8.11 / Monitoring Fluid Therapy 8 Physical Monitoring fluid therapy for the desired effect as well as potential adverse effects is necessary for a successful outcome. No one parameter or value can evaluate fluid therapy; it is a combination of results and trends over time. Along with monitoring the patient for dehydration and overhydration, the equipment (e.g., catheter, administration set, fluid bag, pump) must also be monitored for proper function. 366 Assessment Dehydration Normal Overhydration Comments Blood Pressure • Hypotension • See Table 8.2, Blood Pressure Results, page 337. • Hypertension • See Table 8.1 Blood Pressure Procedure, page 335. Capillary Refill Time • ↓ CRT • 1–2 seconds • ↑ CRT • Assesses peripheral perfusion Heart Rate, Pulse Rate, and Effort • Tachycardia • Weak pulses • Canine: 70–180 bpm • Feline: 110–220 bpm • Tachycardia, gallop • Strong or bounding pulses • Assesses cardiovascular status and intravascular fluid volume status Mentation • Depressed, dull • Calm, relaxed • Agitated, restless Physical Examination • Sunken eyes • See Table 2.2 Physical Examination, page 18. • Serous nasal discharge, ↑ jugular pulses, pitting edema, chemosis, dyspnea • Performed multiple times a day to evaluate hydration and calculate ongoing losses Pulmonary Auscultation • N/A • Heard equally on both sides • Smooth, quiet sound • Cough, pulmonary edema, harsh lung sounds, crackles, rales • See Table 2.3 Pulmonary Examination, page 32. Respiratory Rate and Effort • Variable • Canine: 10–30 breaths/min • Feline: 25–40 breaths/min • Tachypnea, dyspnea Skin Turgor • ↓ Skin turgor • <2 seconds • ↑ Skin turgor • See Table 8.17 Hydration Assessment, page 360. Urine Output • <1 mL/kg/hr • 1–2 mL/kg/hr • Alteration from normal • Assesses renal function and perfusion (GFR) Weight • ↓ Weight • Variable • ↑ Weight • Monitor weight 3–4 times a day with aggressive fluid administration and daily with maintenance rates. • ↑ Weight may be a sign of developing pulmonary edema or elevated CVP. • An ↑ of 1 kg equals 1 L of fluid. • Body weight ↑ by the % of dehydration indicates a need to change to a maintenance fluid rate from that point forward. SECTION FOUR: PATIENT CARE SKILLS Laboratory Table 8.11 / Monitoring Fluid Therapy (Continued) Assessment Dehydration Normal Overhydration Comments Central Venous Pressure • −2 to +5 cm H2O • <8 cm H2O • >10 cm H2O or an ↑ of more than 5 cm H2O within a 24hour period • Assesses true venous return to the heart • Low pressure reflects low effective circulating volume. • High pressure may reflect fluid overload, rightsided myocardial failure, or restrictive pericarditis. Electrolytes • N/A • See Table 4.2 Blood Chemistries, page 76. • N/A • Evaluated to determine the need for replacement therapy Packed Cell Volume • ↑ PCV, >50% • Canine: 37%–55% • Feline: 24%–45% • ↓ PCV, <20% • Assesses hydration status and hemodilution effect of rapid crystalloid infusion Temperature • Variable • 100.5–102.5° F • Hypothermia, shivering • A rise of 1.8° F may require a 10% ↑ in the maintenance fluid rate. Total Protein • >8.0 g/dL • Canine: 5.4–7.6 g/dL • Feline: 6.0–8.1 g/dL • <4.0 g/dL • Assesses the relative serum oncotic pressure • A ↓ in oncotic pressure allows more fluid to flow into the interstitium, causing edema (e.g., pulmonary, SQ). 8 BLOOD TRANSFUSIONS Blood transfusions have become very popular with the wide availability of blood products. National commercial animal blood banks have been established along with many in-hospital donor programs. With this available treatment option, increased knowledge has been gained, leading to the promotion of blood component therapy. Treating each patient according to their individual needs with specific blood components decreases the possibility of transfusion reactions and allows multiple patients to benefit from each unit of blood. CHAPTER 8 / PATIENT CARE 367 Table 8.12 / Blood Types The first step to performing a blood transfusion is the full understanding of blood types for both the canine and feline. Misinformation in this step can lead to serious transfusion reactions and even death. Blood types are distinguished by different genetic markers on the surface of the RBC. These genetic markers are antigenic and to different degrees cause the immune system to react to unmatched transfused blood to form antibodies (alloantibodies or isoantibodies). These antibodies are found in the plasma and can lead to reactions that can cause minor to severe transfusion reactions. Dogs have more than 12 different blood groups and multiple blood types. The genetic markers on the surface of the RBC are known as dog erythrocyte antigens (DEAs). Dogs do not have naturally occurring alloantibodies and are designated as either positive or negative for a specific antigen (e.g., DEA 1.1+ or DEA 1.1−). DEA 1.1+ is found in over 50% of dogs and is currently the most clinically significant in dog transfusion reactions. Transfusing a DEA 1.1− dog (recipient) with DEA 1.1+ blood will allow the recipient to form alloantibodies, leading to immediate reactions or potentially life-threatening reactions on following transfusions. There are also other known and unknown blood types that can lead to transfusion reactions on the first and subsequent transfusions. Cats have only 1 blood group but 3 blood types: A, B, and AB. These blood types, like dogs, are distinguished by specific antigens found on the membranes of the RBCs. All cats have naturally occurring antibodies specifically directed against the antibody they lack (e.g., A or B). Therefore, a transfusion of mismatched blood types will lead to immediate and possibly life-threatening reactions. Even though the overwhelming majority of cats have type A blood, cats with blood type B have the strongest alloantibodies against type A blood and suffer the most severe reactions. Although uncommon, type B blood is most commonly found in certain breeds and concentrated in certain geographical locations. 8 Feline Blood Types Prevalence Naturally Occurring Alloantibodies Mismatched Transfusion Reactions A • Most prevalent worldwide • 99.7% of cats • Weak anti-B antibodies at a low titer • Administering type B blood: acute hemolytic transfusion reaction (↓ cell life) • Less severe reaction than administering type A blood to a type B patient B • 0.3% of all felines • >30%: Devon Rex, British Shorthair, Exotic Shorthair, Turkish Van, Turkish Angora • 15–30%: Abyssinian, Birman, Himalayan, Persian, Somali • Certain geographical areas with DSH • Strong anti-A antibodies at a high titer • Administering type A blood: apnea, hypotension, cardiac arrhythmias, collapse, death AB • Extremely rare • Abyssinian, Birman, British Shorthair, DSH, Japanese Bobtail, Norwegian Forest, Persian, Scottish Fold, Somali • Lack antibodies to type A or B blood • Universal recipient • None based on blood type 368 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.20 / Blood Collection To ensure the quality of each unit of blood obtained, a strict collection protocol must be followed. Each donor should only be selected once he or she has fulfilled all the protocol requirements. Once selected, 13–17 mL/kg in dogs and 10–12 mL/kg in cats of blood can be collected monthly. Blood is collected into a closed system, which is also airtight and sterile. The most important step to blood collection is sterility. Sterility must be maintained through every step of the process to avoid nonimmunogenic transfusion reactions. Throughout the process, the donor’s status must be continuously evaluated (e.g., mucous membranes, pulse rate and strength, respiratory rate). Any sign of donor compromise is cause for potential discontinuation. Donor Requirements Canine • Easy to handle and neutered • No health concerns or current medications • Current vaccinations • Currently taking heartworm preventative • >50 lb ideal • 1–7 years of age Testing Collection Supplies Procedure • Complete physical examination • Blood typing • Baseline laboratory work • CBC, biochemical profile, urinalysis, thyroid hormone, fecal examination, von Willebrand’s factor • Infectious disease screening • Dirofilaria immiti, Erhlichia canis, Babesia canis, B. gibsoni, Brucella canis, Bartonella • Additional testing may be necessary depending on the breed and geographical area. • Blood donor bag and tubing • Venipuncture needle • Anticoagulant • CPDA-1, CPD • Shelf-life of 28–35, 21 days, respectively • 14 mL/100 mL of blood • Sodium citrate • Shelf-life of 48 hours • 1 mL/7–8 mL of blood • Guarded hemostat • Tube sealing • Aluminum sealing clips • Electric sealer • Tubing sealer stripper or household pliers 1. Clamp the tubing behind the needle. 2. Add anticoagulant to the blood donor bag, paying close attention to sterility. 3. Charge the tubing with anticoagulant as the blood must flow through the anticoagulant to the bag. 4. Prepare and perform sterile venipuncture. 5. Place the collection bag as far below the patient as the tubing will allow. 6. Frequently mix the bag and anticoagulant to prevent clotting during collection. 7. Collect the desired amount of blood; then clamp the tubing next to the needle and remove from the donor. 8. Strip the tubing of blood, mix the bag, and allow the tubing to refill with blood. 9. Seal the tubing, cut off excess and remove clamped hemostat. CHAPTER 8 / PATIENT CARE 369 8 Skill Box 8.20 / Blood Collection (Continued) Donor Requirements • Easy to handle and neutered • No health concerns or current medications • Current vaccinations • >10 lb • 1–7 years of age Collection Supplies • Complete physical examination • Blood typing • Baseline laboratory work • CBC, biochemical profile, urinalysis, thyroid hormone, fecal examination • Infectious disease screening • FeLV, FIV, Mycoplasma hemofelis, Bartonella spp. • Additional testing may be necessary depending on the geographical area. • • • • 370 • • • • • Feline 8 Testing SECTION FOUR: PATIENT CARE SKILLS Blood donor bag and tubing 19-gauge butterfly catheter 3-way stopcock Anticoagulant • CPDA-1, CPD • Shelf-life of 28–35, 21 days, respectively • 1.4 mL/10 mL of blood • Sodium citrate • Shelf-life of 48 hours • 1 mL/7–8 mL of blood Guarded hemostat 12 mL syringe 60 mL syringe Tube sealing • Aluminum sealing clips • Electric sealer Tubing sealer stripper or household pliers Procedure 1. Assemble the stopcock, donor bag, tubing and syringe. 2. Place the stopcock in the off or closed position. Note: At no time should the stopcock be positioned to allow outside air to enter the tubing, leading to contamination. 3. Add anticoagulant to the injection port of the 60 mL syringe, paying close attention to sterility. 4. Place the stopcock in the open position to charge the butterfly catheter tubing with anticoagulant, as the blood must flow through the anticoagulant to the bag. 5. Remove the hemostat and connect the donor tubing to the catheter tubing. Note: Sedation and IV fluids may be required for feline donors. 6. Prepare and perform sterile venipuncture. 7. Gently and lightly aspirate blood into the syringe. 8. Collect the desired amount of blood, place the stopcock in the closed position, and remove the needle from the donor. 9. Gently invert the syringe several times to mix the anticoagulant with the blood. 10. Transfer the blood from the syringe into the blood donor bag. 11. Strip the tubing of blood, mix the bag, and allow the tubing to refill with blood. 12. Seal the tubing and cut off. Table 8.13 / Blood Products Blood Product Contents Use / Action Storagea Preparation / Administration Whole Blood, Stored (SWB) • RBCs, WBCs, plasma proteins • Use • Anemia, hypoproteinemia • Large volume deficits • Action • ↑ Blood volume and oxygencarrying capacity • Storage: 4° C (39.2° F) • Shelf-life: 48 hours with sodium citrate and 28 days with CPDA-1 • Preparation • A change in color (e.g., purple, brown, green) or texture (e.g., clots) may indicate contamination • ± Warm to <35° C (98.6° F) • Administration • Volume: 6–12 mL/kg (2 mL of whole blood/kg will raise the PCV 1%) • General: 10 mL/kg/hr until desired PCV reached • Rate: initial rate of 0.1–1 mL/min for 30 minutes, with a gradual ↑ to 4–6 mL/ min as the patient allows • Caution: canine CHF: ≤5 mL/kg/day Packed RBCs (pRBC) • Most of the supernatant plasma removed • 80% PCV • Use • Anemia • Animals in fear of fluid overload (e.g., CHF) • ↓ Risk of exposure to plasma antigens • Action: • ↑ Oxygen-carrying capacity • Separated from unrefrigerated whole blood within 8 hours of collection • Storage: 4° C (39.2° F) • Shelf-life: 35 days with CPDA-1 and 21 days with CPD • Gently mix refrigerated bags twice weekly • Preparation • A change in color (e.g., purple, brown, green) or texture (e.g., clots) may indicate contamination • ± Warm to <35° C (98.6° F) • Addition of 0.9% sterile saline may be needed to ↓ viscosity of the pRBCs. • Administration • Volume: 6–12 mL/kg • 1 mL of whole blood/3 lb of BW will raise the PCV 1.5% • Rate: initial rate of 0.1–1 mL/min for 30 minutes, with a gradual ↑ to 4–6 mL/ min as the patient allows • Use • Coagulation factor deficits, DIC, severe liver disease, vitamin K deficiency, pancreatitis, severe parvovirus enteritis • Hypoproteinemia and hypoglobinemia • Prolonged PT/APTT • Control of active bleeding • Preoperative prophylaxis • Action • Full activity of all coagulation factors • Expand extracellular fluid volume. • Frozen within 8 hours of collection • Storage: −20° C (1° F) • Shelf-life: 1 year, then can be relabeled as FP for an additional 4 years • Preparation • Plasma bags are brittle and should be warmed in their transport box and then inspected for cracks prior to administration. • Unopened bags can be refrozen with minimal loss of activity. • Warm to <35° C (98.6° F). • Administration • Volume: 6–12 mL/kg • Rate: initial rate of 1–2 mL/min to a maximum rate of 3–6 mL/min, administer within 1–2 hours to allow therapeutic plasma levels to be obtained Fresh Frozen Plasma (FFP) • Plasma supernatant • Hemostatic proteins, albumin, globulins, coagulation factors CHAPTER 8 / PATIENT CARE 371 8 Table 8.13 / Blood Products (Continued) Blood Product Contents Use / Action Storagea Preparation / Administration Frozen Plasma (FP) • Plasma supernatant • Hemostatic proteins, albumin, globulins, coagulation factors (II, VII, IX, X) • Use • Coagulation factor • Hypoproteinemia and hypoglobinemia • Action • Full activity of coagulation factors II, VII, IX, and X • Low activity of coagulation factors V and VIII • Frozen >8 hours after collection • Storage: −20° C (1° F) • Shelf-life: 5 years • Preparation • Plasma bags are brittle and should be warmed in their transport box and then inspected for cracks prior to administration. • Unopened bags can be refrozen with minimal loss of activity. • Warm to <35° C (98.6° F) • Administration • Volume: 10–20 mL/kg • Rate: initial rate of 1–2 mL/min to a maximum rate of 3–6 mL/min, administer within 1–2 hours to allow therapeutic plasma levels to be obtained Cryoprecipitate • Heavy, cold-insoluble proteins • 50% yield of factor VIII • von Willebrand’s factor, fibrinogen, fibronectin • Use • Hemophilia A, von Willebrand disease, fibrinogen deficiency, or dysfunction • Topical hemostatic in surgery • Action • Coagulation factor replacement • Storage: −20° C (1° F) • Shelf-life: 1 year • Preparation • Plasma bags are brittle and should be warmed in their transport box and then inspected for cracks prior to administration. • Warm to <35° C (98.6° F) • Thawed product may be refrozen within 2 hours without effect. • Administration • Volume: 1–2 mL/kg • Rate: slow IV bolus over 10–20 minutes Oxyglobin • Acellular oxygencarrying replacement fluid • Derived from bovine hemoglobin • Use • ↑ Intravascular volume • Alleviates the risk of RBC sensitization • ↑ Oxygen-carrying capacity • Action • Carries O2 and CO2 similar to hemoglobin • Expand extracellular fluid volume. • Storage: room temperature or refrigerated • Shelf-life: 3 years • Preparation • ± Warm to <35° C (98.6° F) • Administration • Volume: 10–30 mL/kg • Rate: IV to a maximum rate of 10 mL/kg/hr • Used within 24 hours after removing the foil packaging • Indicated for canines only 8 a Storage referring to blood collected in a closed collection system. 372 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.21 / Blood Administration Transfusion Protocol Patient Blood Preparation • Perform blood typing and a crossmatch before every transfusion. • Catheter • The catheter must be dedicated to transfusion use only. • Technique • Place an IV catheter with strict aseptic technique. • To use an existing catheter, flush the catheter before and after the transfusion with 0.9% sterile saline. • Inspection • Verify the correct patient and blood type have been selected. • Each bag should be thoroughly inspected prior to administration for changes in the integrity of the bag, changes in blood color, and presence of hemolysis or clots. • Warming • Refrigerated products do not need to warmed unless large volumes are to be given or the patient is hypothermic. • Temperatures > 37° C (98.6° F) may lyse RBCs (↓ oxygen-carrying capacity, inactivate proteins and clotting factors) and accelerate bacterial overgrowth. • Techniques • Place bag at room temperature for 30 minutes. • Place blood bag (and transport box if included) into zip-lock bags (to avoid infusion port contamination and damage to brittle bags) and submerge bags into a container of warm water for 15 minutes or until ≤37° C (98.6° F). • Run the IV tubing through warm water during the transfusion. Setup • Place the patient in a clean comfortable cage with white bedding to observe for hemoglobinuria. • Place in an area of the hospital allowing continuous visual monitoring by all staff. • Filters • A blood administration set with an inline 170- to 270-μm pore, non-Latex filter should be used to remove clots and debris collected during storage. • Filters are functional for 2–4 units of blood or for a maximum use of 4 hours. • No fluids (LRS, D5W, hypotonic saline) or medications should be added to a blood bag except 0.9% sterile saline, to avoid triggering coagulation (e.g., calcium in fluids). Monitoring • Obtain baseline vital signs before beginning the transfusion (e.g., urine color, PCV, temperature, pulse, RR). • Obtain basic vital signs very 5 minutes for 15–30 minutes. • Continue monitoring every 15 minutes for the duration of the transfusion. • Routes • IV is the preferred route of transfusions, but intraosseous catheters can be used in patients with difficult venous access with excellent results (e.g., femur, tibia, humerus). • Ratea • The rate is based on the blood product, recipient size, and health status. • The initial slow rate of 0.1–1 mL/min for 30 minutes, with a gradual ↑ to 4–6 mL/min as the patient allows. • Blood may be administered by gravity or through a infusion pump rated to delivery blood products while causing no harm to the cells. • Transfusions should be completed within 4 hours to ↓ bacterial overgrowth. Administration a See Skill Box 8-19 Calculating Drip Rates, page 365. Note: Storage of blood samples from the donor and recipient for 1 week post transfusion can be used if the event of an adverse reaction. Note: 10 mL/kg of packed RBCs or 20 mL/kg of whole blood ↑ the PCV by 10% if the donor has a PCV of approximately 40% (Thrall, 2004, p. 200). CHAPTER 8 / PATIENT CARE 373 8 Table 8.14 / Blood Transfusion Reactions Transfusion reactions under most circumstances can be avoided with attention to detail. With the proper selection and testing of donors, proper collection of blood and proper handling and care of blood products and IV catheters, the majority of transfusions will take place uneventfully. However, reactions do occur due to factors that cannot be tested for or expected. Reactions can be seen either acutely (within minutes to hours) or delayed (days to years) and are divided into either immunologic or nonimmunologic. Immunologic reactions are caused by an antigen–antibody response between the recipient and the donor blood product. Nonimmunologic reactions are seen with inadequate donor screening, contamination, improper handling or administration techniques, or cytokine activation in the blood product. The most common reaction is volume overload; merely reducing the administration rate can often remedy this situation. Treatments for transfusion reactions are directed toward alleviating clinical signs and basic supportive care. Fluid support, oxygen support, diuretics, antipyretics, steroids, and antihistamines are the most common treatments initiated. Reaction Cause Signs Acute Immunologic • Typically occurs within minutes of initiating transfusion • RBC • Intravascular or extravascular hemolysis, fever, anaphylaxis, hypotension, tachy- or bradycardia, cyanosis, apnea, salivation, lacrimation, urination, defecation, emesis, collapse, acute renal failure, shock, death • Platelets, WBC • Fever, emesis • Plasma proteins • Urticaria, facial edema, erythema, pruritis • Contamination • Fever, sepsis, infection, hypotension, hemolysis, vomiting, DIC, renal failure, shock, emesis, diarrhea • Blood products: dark, discoloration of RBCs, clumped cells, hemolysis, air bubbles • Improper collection • Hemolysis, emesis, edema, dyspnea • Volume overload • Dyspnea, emesis, retching, pulmonary edema, vocalization, tachycardia, coughing, tachypnea, cyanosis • Microaggregates • Thrombosis • Citrate toxicity (hypocalcemia toxicity) • Tetany, tremors, cardiac arrhythmias, emesis, ECG changes • RBC • ↓ PCV, fever, icterus, shortened red cell survival • Neonatal hemolysis • Platelet • Thrombocytopenia, petechiae extravascular hemolysis (e.g., hyperbilirubinemia, hemoglobinuria, bilirubinuria) • Infected donor • Disease transmission (e.g., FeLV, FIV) Acute Nonimmunologic 8 Delayed Immunologic • Occurs over days Delayed Nonimmunologic Note: Fever is considered to be a >1° C (2° F) increase over the pretransfusion temperature within 1–2 hours. 374 SECTION FOUR: PATIENT CARE SKILLS OXYGEN THERAPY The objective of oxygen therapy is to provide adequate oxygen to the arterial blood and to remove carbon dioxide. Any acutely ill or injured patient has a higher demand for oxygen and should be provided supplemental oxygen until stabilized. Monitoring the patient who is receiving supplemental oxygen is crucial. Hyperthermia, increased humidity, and CO2 can be fatal. Skill Box 8.22 / Oxygen Administration Oxygen administration requires the following equipment: an oxygen source, a humidifier, oxygen tubing, and Christmas tree adapters or syringe case. Humidification The normal function of the respiratory tract is to warm and humidify inspired gases. With oxygen supplementation this process is lost, leaving the patient with cold and dry inspired gases. Providing humidified oxygen can reduce the risk of increased water loss and drying of the lower airway, predisposing the patient to pneumonia. Humidification should be provided for all patients receiving long-term oxygen supplementation or when delivered directly into the nose, ET tube, or trachea. The humidifier should be cleaned and dried after each patient. Oxygen Flow Rates Oxygen is toxic at high concentrations. Maintaining levels of O2 at >60% for longer than 12 hours can pose a problem. Oxygen levels should only be maintained at concentrations of 40% when used for long-term oxygen supplementation. • Flow by: 3–15 L/min • Oxygen hood: 200 mL/kg/min • Nasal catheter: small canines and felines, 50 mL/kg/min; larger canines, 100 mL/kg/min Oxygen Flow-by Connect the oxygen tube to the gas source and run at 6 L/min. Place the open end of the tube about 6 inches from the patient’s mouth/ nose. Avoid directing the flowing into the nares as this can cause irritation. Mask Connect the oxygen tube to the gas source and run at 6 L/min. Connect an anesthetic mask to the open end of the tube and place over the patient’s mouth and nose. The mask can be kept in place with a muzzle. Be sure the fit is not so tight that CO2 is prevented from escaping. Carrier/Box A method best used with fractious or overly stressed cats. Place a clear plastic bag (e.g., garbage can liner) over the entire carrier or box or tape the openings shut. (A paper flap can be placed over one opening or just left open to allow an exhaust escape.) Connect the oxygen tube to the gas source and run at 6 L/min. Place the open end of the tube inside a hole in the clear bag. This method provides no control of heat or airway; therefore, the patient should be monitored closely. The methods listed below are for longer-term oxygen administration. Each technique has its own advantages and disadvantages. Immediate and Temporary Approaches to Respiratory Distress The methods listed here are for immediate and temporary use. The patient tolerance is typically high. CHAPTER 8 / PATIENT CARE 375 8 Routes of Oxygen Administration Skill Box 8.23 / Routes of Oxygen Administration: Oxygen Hood and Nasal Catheter 8 Method Oxygen Hood Nasal Catheter Indications • Respiratory distress • Hypoxemia • Respiratory distress • Hypoxemia Contraindications • • • • • • • • • Setup • Specialized oxygen hood E-collars or • E-collar • Saran Wrap Procedure Saran wrap is taped to the outside of an E-collar to cover 3/4 of the opening. The opening at the top is for CO2, heat, and condensation to escape. The E-collar is placed over the patient’s head and secured with gauze or using the patient’s collar. The oxygen tube is fed in at the neck opening and secured near the front of the E-collar with tape. Place several drops of topical anesthetic in the nostril to be used. Be sure to elevate head to allow coating of the nasal passage. Measure the tube from the nostril to the medial canthus of the eye and mark. Place several more drops of anesthetic in the nostril. Place a simple interrupted suture at the lateral commissure of the nose and another somewhere between the eyes to on top of the head. Lubricate the tip of the tube with lidocaine gel. Using your thumb, push up on the nose into a pig position, then insert the tube ventrally and medially to the level of the mark on the tube. Using the sutures previously placed; connect with a Chinese finger trap suture. See Skill Box 15.4 Suture Patterns, page 549. Complications • Hyperthermia • Sneezing • ↑ Stress Removal • Remove E-collar • Remove sutures and gently, but swiftly remove the catheter Airway obstruction Panting Hyperthermia ↑ Stress • Tape • Tie (e.g., gauze, collar) • Oxygen setup Airway obstruction, nasal or facial trauma ↑ Stress Epistaxis, coagulopathies ↑ Intracranial pressure Brachycephalic breeds • Red rubber catheter • Small patients: 3.5–5 Fr • Medium canines: 5–8 Fr • Large canines: 8–10 Fr • Topical anesthetic (e.g., proparacaine, lidocaine gel) • • • • • Permanent marker Suture, nonabsorbable Needle holders Oxygen setup E-collar Tip: Selecting a larger red rubber catheter for nasal catheters provides increased patient tolerance. It is speculated that it fills the space, eliminating movement and tickling, and eliminates the higher-pressure hose effect when the O2 is turned on. 376 SECTION FOUR: PATIENT CARE SKILLS Skill Box 8.24 / Routes of Oxygen Administration: Transtracheal Catheter and Tracheostomy Method Transtracheal Catheter Tracheostomy, emergency Indications • • • • • Airway obstruction • Laryngeal or pharyngeal collapse • Long-term PPV Contraindications • Tracheal trauma or injury • Airway obstruction distal to catheter placement • Tracheal trauma or injury • Airway obstruction distal to tracheostomy site Setup • • • • • • • • • • • Procedure Patient is placed in dorsal recumbency and the neck is surgically prepped from the ramus of the mandible to the thoracic inlet and dorsally to midline. An incision is made over the larynx and is bluntly dissected down to the trachea. Insert the catheter along a groove director. Once in the trachea, remove the groove director and stylet and direct the catheter to the level of the carina. Secure the catheter to the skin with Chinese finger trap sutures. Loosely apply bandage around the catheter. Patient is placed in dorsal recumbency and the neck is surgically prepped from the ramus of the mandible to the thoracic inlet and dorsally to midline. An incision is made over the larynx and is bluntly dissected down to the trachea. Two stay sutures are placed around the 4th and 5th tracheal rings and are used to retract the opening. An incision is made between the rings while avoiding cutting more 35% of the circumference of the trachea. The stay sutures are retracted and the tracheostomy tube is inserted. The tube is secured with tape. Complications • Tracheal trauma or injury • Tracheitis, SQ emphysema, catheter kink or obstruction, pneumomediastinum, hematoma • Tracheal trauma or injury Maintenance • All contact should be performed aseptically. • Monitor respiratory rate, lung sounds, and all vital signs. • Monitor site for infection, kinking, SQ emphysema, and dislodgment. • Change bandages frequently. • All contact should be performed aseptically. • Preoxygenate patient before any procedure. • Suction 3–4 times every 30–60 minutes for 3–7 seconds; supplemental oxygen may be needed between suctioning. • Monitor respiratory rate, lung sounds, and all vital signs. • Nebulize and coupage 3–4 times a day. • Tube should be changed daily. • Instill sterile saline (1 mL/10 kg) every 3–4 hours. Removal • Remove the tube and allow the wound to heal by second intention. • Remove the tube and stay sutures and allow the wound to heal by second intention. Upper airway obstruction Head, facial, or nasal trauma Epistaxis or coagulopathies Patients not tolerant of nasal catheters or those requiring a higher flow rate than tolerated by a nasal catheter Surgical site preparation materials Sedation or general anesthesia Sterile surgical pack Tracheal catheter or large bore over the needle catheter Oxygen set up Bandaging material Surgical site preparation materials Sedation or general anesthesia Tracheostomy tube (various sizes) Sterile surgical pack Suture material CHAPTER 8 / PATIENT CARE 377 8 Chapter 9 Pain Management Pain Management 380 Pain Assessment 381 Pain Scales 381 Instructions for Using the CSU Acute Pain Scale 382 Pain Levels Associated With Surgical Procedures, Injuries, and Illness 383 Behaviors Suggesting Pain and Anxiety 384 Nondrug Approach to Decrease Pain and Anxiety 386 Pain Management Drugs 386 Pain Management Techniques 392 Constant Rate Infusions 392 Setting Up a Morphine/Lidocaine/Ketamine Constant Rate Infusion 393 9 379 Key Words and Phrasesa Abbreviations Additional Resources, page Agonists Allodynia Analgesics Antagonists Extracapsular Hyperalgesia Hyperesthesia Normotensive Normovolemic Receptors Wind-up phenomenon μg, microgram CNS, central nervous system CRI, constant rate infusion FLK, fentanyl/lidocaine/ketamine GDV, gastric dilation volvulus GI, gastrointestinal HCl, hydrochloride HLK, hydromorphone/lidocaine/ketamine hr, hour IM, intramuscular IV, intravenous kg, kilogram lb, pound LRS, lactated Ringer’s solution mg, milligram min, minute mL, milliliter MLK, morphine/lidocaine/ketamine NRS, numerical rating scale NSAIDs, nonsteroidal anti-inflammatory drugs OVH, ovariohystrectomy PO, by mouth Q24, every 24 SDS, simple descriptive scale SQ, subcutaneous UMPS, University of Melbourne Pain Scale VAS, visual analog scale Blood chemistries, 74 Fluid therapy, 359 Injections, 348 Kilograms to body surface area, 627 Patient care, 329 Patient monitoring, 332 Pharmacology, 567 Recumbent patient care, 347 Surgery, 521 Vital signs, 19 9 a Key words and terms are defined in the glossary on page 631. PAIN MANAGEMENT Animals do not uniformly respond to pain or stress in the same way. Their breed, age, previous experiences, and degree of illness and stress can alter their response to a stimulus. Research shows that a patient’s normal functions return sooner and they recover and heal quicker with pain control. In the past, the hardest part of pain control was trying to decide when the patient was truly in pain. It is now known that preemptive treatment is the best method. Do not wait for the patient to prove he or she is in pain; assume, after a surgical procedure and during illness and injuries, that a patient is experiencing pain. To ensure a patient’s comfort, continual observation and appropriate treatment are needed, especially in the first 12–24 hours. The pain pathway begins with the stimulation of receptors and peripheral nerves through the conversion of a chemical, mechanical, or thermal insult into a nerve impulse. The signal is then conducted through the spinal cord to the 380 SECTION FOUR: PATIENT CARE SKILLS brain, where it is perceived as pain. The degree of pain is related to the number of receptors in the injured tissue. The skin, periosteum, joint capsule, muscle, tendon, and arterial wall contain the highest density of pain receptors. The peripheral nervous system is the source of the intense sharp pain felt with an injury. This is directly related to the number and location of pain receptors. The central nervous system produces burning, throbbing pain because of the low density of pain receptors found there. The internal organs require a major insult on the organ to produce intense pain. Typically, it is hard to locate diffuse pain in contrast to the easily located intense pain associated with the peripheral nervous system. Pain Management Myths 1. Analgesics mask the physiologic indicators of patient deterioration. Evidence exists in both human and veterinary medicine showing that this is not the case. In fact, if the patient were treated adequately for pain, any changes in physiologic indicators would indeed be attributable to patient deterioration rather than a pain stress response. 2. Potential for toxicity or adverse reactions is associated with drug administration. With our current level of understanding, there is no longer an overpowering reason to avoid the use of analgesics. Many drug options exist for both canines and felines, with proven guidelines to allow safe administration. 3. Pain is hard to recognize. It is best to think of pain in terms similar to human pain. Treat for this level of pain regardless of whether you think the animal is truly showing signs of pain. Assume that invasive procedures, trauma, and illness result in a need for analgesics. Merely being aware and observing for behavioral signs of pain will make recognition easier. 4. Pain keeps an animal from moving around and injuring itself. Through research, pain makes a patient more agitated and unable to relax and rest. Pacing, changing position, and chewing at the incision are behaviors that indicate pain versus boredom or agitation. Continuous pain can also contribute to poor healing, decreased immune function, and increased inflammation. In cases of excessive activity, sedation and confinement can be used to control the activity level of the patient. 5. The breed is just “a wimp.” Each animal and human experiences and exhibits pain differently. Some breeds tend to show stronger reactions to pain, therefore having a lower threshold to pain. This additional knowledge can lead to better preemptive pain management in particular breeds. Pain Assessment The assessment of pain in someone other than yourself is a very difficult task, especially when dealing with another species. There are many ways to assess a patient’s level of pain; however, not one single method provides a complete picture. Observant and thorough patient care is the most important part of pain assessment. It is through this keen awareness and the use of alternate methods that a thorough pain management plan can be formulated. The 4 most common approaches are physiologic responses, the use of preestablished pain scales, expected pain, and the patient’s behavior. Physiologic signs are the least predictable signs when assessing pain, as many of the same physiologic signs can also be seen with fear, anxiety, and excitement. Increased heart rate, increased respiratory rate, hypertension, dilated pupils, and increased serum cortisol and epinephrine are all signs potentially relating to pain. Table 9.1 / Pain Scales (See figures in Color Plate 23–24) Pain scales formulated through research and anecdotal hospital situations provide another means of evaluating patients. Each scale has its advantages and disadvantages and should be used with those in mind. Observer training is the key to using these systems appropriately and consistently. Pain Scale Definition Simple descriptive scale (SDS) • Ease of use Utilizes a numbering system based on the observation of the patient to indicate the level of pain, with (0) indicating no pain and (4) indicating extreme pain Preemptive scoring system Estimate of expected pain based on the procedure to be performed, and the amount of tissue trauma expected rated as none, mild, moderate, or severe Visual analog scale (VAS) Advantages • Ease of use A 100 mm straight line bracketed with “No Pain” • Ease of use and one end and “Worst Pain Possible” at other • Visual indication if pain is improving or end. A vertical line is draw across the line to worsening indicate the patient’s level of pain. Disadvantages • Observer bias • Individual patient extent of pain and response to therapy • Subjective nature of where to stop the line • Uncertainty of what “Worst Possible Pain” indicates, relating to all pain or pain for a specific procedure CHAPTER 9 / PAIN MANAGEMENT 381 9 Table 9.1 / Pain Scales (Continued) Pain Scale Definition Advantages Disadvantages Numerical rating scale (NRS) A set of categories used to evaluate the patient on visual and physiologic observations • Ease of use • Encourages a thorough patient evaluation • Similar to SDS • Limited validation Behavioral and Physiologic Response Scales 9 Colorado State University Acute Pain Scale • See Skill Box 9.1 • See Color Plate 9.1 • See Color Plate 9.2 Evaluation of psychologic and behavioral signs, responses to palpation and body tension • Limited observer bias • Observations clearly defined • Limited validation University of Melbourne Pain Scale (UMPS) Evaluation of psychologic and behavioral signs • Increased accuracy • Ability to weigh the importance of different categories • Limited validation The Glasgow Composite Pain Tool Evaluation of specific behavior signs • Limited observer bias • Observations clearly defined • Avoids variable physiologic responses • Greater use for musculoskeletal Skill Box 9.1 / Instructions for Using the CSU Acute Pain Scale Use of the scale employs both an observational period and a hands-on evaluation of the patient. In general, the assessment begins with quiet observation of the patient in its cage at a relatively unobtrusive distance. Afterward, the patient as a whole (wound as well as the entire body) is approached to assess reaction to gentle palpation, indicators of muscle tension and heat, response to interaction, etc. 1. The scale utilizes a generic 0–4 scale with quarter marks as its base along with a color scale as a visual cue for progression along with the 5-point scale. 2. Artists’ realistic renderings of animals at various levels of pain add further visual cues. Additional drawings provide space for recording pain, warmth, and muscle tension; this allows documentation of specific areas of concern in the medical record. A further advantage of these drawings is that the observer is encouraged to assess the overall pain of the patient in addition to focusing on the primary lesion. 3. The scale includes psychologic and behavioral signs of pain as well as palpation responses. Further, the scale uses body tension as an evaluation tool, a parameter not addressed in other scales. 382 SECTION FOUR: PATIENT CARE SKILLS 4. There is a provision for nonassessment in the resting patient. To the authors’ knowledge, this is the only scale that emphasizes the importance of delaying assessment in a sleeping patient while prompting the observer to recognize patients that may be inappropriately obtunded by medication or a more serious health concern. 5. Advantages of this scale include ease of use with minimal interpretation required. Specific descriptors for individual behaviors are provided which decreases interobserver variability. Additionally, a scale is provided for both the dog and the cat. 6. A disadvantage of this scale is a lack of validation by clinical studies comparing it to other scales. Further, its use is largely limited to and is intended for use in acute pain. See Figure 9.1, color plate, Colorado State University Canine Acute Pain Scale. See Figure 9.2, color plate, Colorado State University Feline Acute Pain Scale. Table 9.2 / Pain Levels Associated With Surgical Procedures, Injuries, and Illnesses Surgical procedures, illnesses, and injuries are known to cause pain in humans and are thought to do so in animals, also. This chart can be used to preemptively treat animals for expected pain. It will also help to choose the correct drug or combination of drugs to administer when there is an understanding of the level of pain each procedure may produce. Mild to Moderate Moderate Moderate to Severe Severe to Excruciating Surgical • Aural hematoma Procedure • Castration (young animals) • Chest drains • Dental cleaning • Ear examination and cleaning • Mass removal • OVH (young animals) • Tracheotomy • Urinary catheterization • • • • • • • • Anal sacculectomy Castration (older or obese animals) Cystotomy (inflamed) Dental extractions Enucleation Fracture repair (radius, ulna, tibia, fibula) Inguinal hernia repair Laparotomy (short procedure with minimal manipulation and no inflammation) • Mass removal • OVH (older, obese, or pregnant animals) • • • • • • • Disc surgery (thoracic, lumbar) Exploratory laparotomy Laminectomy Mandibulectomy Mastectomy Onychectomy Total ear ablation • • • • Injury • Diaphragmatic hernia repair (acute, simple with no organ injury) • Extracapsular cruciate repair • Fracture repair (radius, ulna, tibia, fibula) • Laceration repair (severe) • Soft tissue injury • • • • • Fracture repair (pelvis) Corneal abrasion or ulceration • Multiple fracture repair with Fracture repair (femur, humerus) extensive soft tissue injury Frostbite • Neuropathic pain (nerve Intra-articular surgical procedure (large entrapment, cervical intervertebral canines or extensive manipulation) disk herniation, inflammation) Mesenteric, gastric, testicular, or other torsions Rewarming after accidental hypothermia Trauma (orthopedic, extensive soft tissue injury, head injury) Traumatic diaphragmatic hernia repair (organ and extensive tissue injury) • Abscess lancing • Laceration repair-minor • Removing cutaneous foreign bodies • • • • Illness • Cystitis • Otitis • Pancreatitis (early or resolving) • Urethral obstruction • Osteoarthritis, acute polyarthritis • Peritonitis Disc surgery (cervical) Ear resections Limb amputation Postsurgical pain (with extensive tissue injury or inflammation) • Thoractomy • Meningitis • Bone cancer (especially after biopsy) • Pathologic fractures • Necrotizing cholecystitis • Necrotizing pancreatitis • Extensive inflammation (peritonitis, fasciitis, cellulitis) CHAPTER 9 / PAIN MANAGEMENT 383 9 Table 9.3 / Behaviors Suggesting Pain and Anxiety Each behavior that an animal portrays may have a variety of meanings. Often, a behavior may be indicative of both pain and a normal behavior. When evaluating whether a patient is in pain, look for multiple behaviors to ensure a correct assessment of pain. Research has shown that animals routinely hide their pain when in the presence of observers making this assessment approach even harder. Remember, it is always best to err on the side of pain and administer a pain medication; most likely a patient is always experiencing some level of pain after a surgical procedure or during an illness or injury. The behaviors listed below are marked based on their possible cause. Pain can cause any behavior, but it may not be the only cause or the cause in a particular patient. Evaluating a large number of behaviors will help in determining a patient’s level of pain. Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health Posture 9 Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health Vocalization Hunched up guarding abdomen X Screaming X X X Tensing abdomen and back muscles X Whining X X X X Splinting of abdomen X Crying X X X X Reluctance to lie down X X None X X X Leaning against cage wall X X Barking/growling (Canine) X X X Sitting or lying in an abnormal position X X Growling/hissing (Feline) X X X Resting in abnormal position X X General Appearance X X Praying position (forequarters on ground, X hindquarters in air) Not grooming X X X Weak tail wag X X Dull eyes X Low carriage of tail X X Ears pulled back X Head hangs down X X Penile prolapse X X Stare into space X X Grimacing X Non–weight bearing (partial or complete) X Sleepy X Stiff X Photophobic Unwilling to walk X Unable to walk X Gait Limping 384 SECTION FOUR: PATIENT CARE SKILLS X X X Ruffled greasy fur X X X X X X X Table 9.3 / Behaviors Suggesting Pain and Anxiety (Continued) Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health Movement Restless, agitated Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health Aggressiveness X X Inability to sleep regardless of obvious exhaustion X X X Physiologic X X X X Tachypnea/panting X X X X Tachycardia X X X X Dilated pupils X X Hypertension X X Increased body temperature X X X X X X Trembling, shaking X X Thrashing X X No movement when sleeping X Lying quietly and not moving for hours and does not dream X Increased salivation Stuporous X Appetite/Elimination X Recumbent and unaware of surroundings X X Inappetance X X Slow to rise X X X Decreased appetite X X Reluctant to move head (eye movement only) X X X Picky appetite X X Stretching all 4 legs when abdomen is touched X Makes no attempt to move to eliminate X Pacing X X Repetitively lying down, getting up, lying X down X X X X X Looking, licking, chewing at painful area X X X 9 X Attitude Bite or attempts to bite caregivers Hyperesthesia/hyperalgesia X Allodynia X X X CHAPTER 9 / PAIN MANAGEMENT 385 Table 9.3 / Behaviors Suggesting Pain and Anxiety (Continued) Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health Sitting in back of cage X X X Hiding under blanket (feline) X X X Cleaning/licking wound X Behavior Pain Poor Apprehension/ Normal General Anxiety Behavior Health X Skill Box 9.2 / Nondrug Approach to Decrease Pain and Anxiety Contact • Visits from owners • Interactions with staff during and in between treatments (e.g., talking, petting, stroking, brushing) Environment • Provide familiar toys and blankets. • Ensure a quiet location, away from loud animals and human noise. • Keep the cage clean and warm. • Provide hiding places for cats (e.g., carriers, boxes). Nursing Care • Schedule the least interruptions possible; combine monitoring, medication administration, and cage moving. • Offer multiple opportunities for canines to urinate or defecate. • Keep the patient comfortable (e.g., clean, dry, rotated often; pressure sores clean; moisten dry mouth). • Monitor catheters and bandages for discomfort. Table 9.4 / Pain Management Drugs There are multiple classes of drugs used for analgesics; the 2 more commonly used are opioids and NSAIDs. The formation of a pain management plan reviews the effects of the different classes and individual drugs to provide a balanced analgesic plan. The use of multiple drugs often gives an additive or synergistic effect, allowing a decreased dosage of each drug and a more complete relief of pain for the patient. Drug Opioids 9 Along with the use of analgesics and sedatives, proper nursing care plays a critical role in helping to alleviate pain. Anxiety and stress lower the threshold to pain sensation. The following should be continuously observed in every patient admitted to the hospital. 386 Indications Buprenorphine HCl • Canine: mild to moderate pain • Partial agonist at μ • Feline: moderate to severe pain receptors • Preoperative sedation, acute and perioperative pain SECTION FOUR: PATIENT CARE SKILLS Dose/Route/Duration Comments Dose • Canine: 0.01–0.03 mg/kg • Felines: 0.005–0.02 mg/kg • Epidural: 0.03 mg/kg • Sublingual: 0.01–0.02 mg/kg Route • Sublingual (felines only), SQ, IM, IV Duration (affected by dose) • Delayed onset of 45–60 minutes • 6–12 hours • Very effective in felines • Sublingual application is only acceptable for felines, due to their unique oral pH • Will not usually achieve the same degree of analgesia as morphine, hydromorphone, or fentanyl • Due to its high affinity for the μ receptor, virtually impossible to reverse Table 9.4 / Pain Management Drugs (Continued) Opioids Drug Indications Dose/Route/Duration Comments Butorphanol Tartrate • Mild to moderate pain • Pure antagonist at • Canine: visceral pain μ receptor and • Feline: skin pain partial agonists at κ receptor Dose • Canine: 0.2–0.8 mg/kg SQ, IM 0.1–0.4 mg/kg IV • Feline: 0.1–0.4 mg/kg SQ, IM 0.05–0.2 mg/kg IV Route • SQ, IM, IV Duration • Canine: 20 minutes (SQ, IM), 45 minutes (IV) • Feline: 4 hours (SQ, IM), 45–60 minutes (IV) • Has an anesthetic ceiling effect in which an ↑ amount will not ↓ the pain further • Can be used to partially reverse pure agonist opioids at μ receptors • Will not usually achieve the same degree of analgesia as morphine, hydromorphone, or fentanyl • Can be given PO, but not highly effective for pain Codeine/ Acetaminophen • Moderate to severe pain • Chronic pain Dose • Canine: 1–2 mg/kg codeine Route • PO Duration • 8–12 hours • Do not use in felines. • Available in 30 or 60 mg codeine and 300 mg acetaminophen (e.g., Tylenol No. 3) • Chronic use: tolerance and constipation may occur Fentanyl Citrate • Pure agonist at μ receptor • Moderate to severe pain Injection Dose • Canine: 10 μg/kg SQ 2–5 μg/kg IV • Feline: 1–2 μg/kg IV • CRI: See Table 9.5, page 392. Route • SQ (canine only), IV Duration • Canine: 40–60 minutes (SQ) • Canine/feline 15–30 minutes (IV) Transdermal patch Dose • Canine/feline: 3–5 μg/kg/hr • <11 lb = 12.5 μg • 11–22 lb = 25 μg • 22–44 lb = 50 μg • 44–66 lb = 75 μg • >66 lb = 100 μg Duration • Delayed onset of 12–24 hours • Canine: minimum of 3 days • Feline: up to 4 days • Feline hyperthermia is often seen. • May cause auditory sensitization, ↑ body temperature and bradycardia • Cotton in the ears and a quiet environment may alleviate signs of sound sensitivity. • Patch is inadequate when used alone with acute surgical pain or severe traumatic pain. • Patch use with febrile patients or with a heating device can greatly ↑ rates of absorption and should be avoided. • The use of mixed agonist/antagonist opioids will reverse the effects. • Patch placement: • Sites may be the neck, thorax, inguinal area, metatarsal/carpal areas, base of tail of canines and lateral thorax, inguinal area, metatarsal/carpal areas, base of tail of felines • Clip hair over desired area, clean with water, and allow to dry completely. • Apply patch, hold in place with palm of hand for several minutes to allow the patch to adhere, and cover with an adhesive bandage. • Label bandage with patch size, date, and time of placement. CHAPTER 9 / PAIN MANAGEMENT 387 9 Table 9.4 / Pain Management Drugs (Continued) Opioids Drug 9 388 Indications Dose/Route/Duration Comments Hydromorphone • Pure agonist at μ receptor • Moderate to severe pain Dose • Canine: 0.1–0.2 mg/kg SQ, IM 0.03–0.1 mg/kg IV • Feline: 0.05–0.1 mg/kg SQ, IM 0.01–0.025 mg/kg IV Route • SQ, IM, IV (slowly) Duration • Delayed onset of 15–30 minutes • 3–4 hours (SQ, IM), 30–45 minutes (IV) • Feline hyperthermia is often seen. • Less likely to induce vomiting or hypotension than morphine • Constipation with long-term use Methadone • Agonist at the μ receptor • Mild to moderate pain Dose • Canine: 0.5–2.2 mg/kg SQ, IM 0.1–0.5 mg/kg IV • Feline: 0.1–0.5 mg/kg SQ, IM 0.05–0.1 mg/kg IV Route • SQ, IM, IV Duration • 4–6 hours (SQ, IM), 60 minutes (IV) • May induce less vomiting and sedation than morphine • Less likelihood of developing tolerance Morphine Sulfate • Pure agonist at μ receptor • Moderate to severe pain Dose • Canine: 0.5–4 mg/kg PO 0.5–2.2 mg/kg SQ, IM 0.1–0.5 mg/kg IV slowly • Feline: 0.25–1.0 mg/kg PO 0.1–0.5 mg/kg SQ, IM 0.05–0.1 mg/kg IV slowly • Epidural: 0.1 mg/kg Route • PO, SQ, IM, IV slowly Duration • 3–4 hours (PO), 3–6 hours (SQ, IM), 60 minutes (IV) • Feline hyperthermia is often seen. • High doses may cause excitement in felines; give lower doses combined with a tranquilizer. • Avoid IV administration in canines that are not normovolemic and normotensive. Oxymorphone HCl • Pure agonists at μ receptor • Moderate to severe pain Dose • Canine: 0.05–0.2 mg/kg • Feline: 0.02–0.1 mg/kg Route • IM, IV Duration • 2–6 hours • Feline hyperthermia is often seen. SECTION FOUR: PATIENT CARE SKILLS Table 9.4 / Pain Management Drugs (Continued) Indications Dose/Route/Duration Comments Tramadol • Synthetic μ receptor opiate agonist • Moderate to severe chronic pain Dose • Canine: 2–5 mg/kg • Feline: 2–3 mg/kg Route • PO Duration • 8–12 hours • Most effective when used in conjunction with an NSAID • Protect from light. • Taper dose at withdrawal. Medetomidine • Mild pain • Moderate to severe pain when combined with opioids Dose • Canine/Feline: 5–10 μg/kg IM, IV Route • IM, IV Duration • 30–90 minutes • Used with opioids to enhance analgesic effects • Extremely excited and agitated dogs need 15–20 minutes of quiet rest time after drug is given. • Use atropine or glycopyrrolate for the bradycardia. • Placement of cotton balls in the patient’s ears and a quiet environment may alleviate signs of sound sensitivity. • Bottle labeled as μg/m2 for dosing; see Appendix Xylazine • Mild pain Dose • Canine/Feline: 0.05–0.1 mg/kg Route • IM, IV Duration • 30–60 minutes • • • • Bupivacaine • Eliminate all pain Dose • Canine/Feline: 1–2 mg/kg • Epidural: 0.1–0.75 mg/kg Route • Infiltration, epidural Duration • Delayed onset of 15–20 minutes • 6–8 hours • Avoid IV administration as cardiac arrest may result. • Toxic dose is 4 mg/kg. Lidocaine • Eliminate all pain Dose • Canine/Feline: 1–2 mg/kg Route • Infiltration, epidural, IV Duration • Onset of 3–10 minutes • 60 minutes • Felines are very sensitive to the CNS effects—use with caution • Avoid IV administration in felines. • Toxic dose is 10 mg/kg. • CRI: See Table 9.5, page 392. Local Alpha–2 Agonists Opioids Drug Sedation may outlast analgesia. Used with opioids to enhance analgesic effects Use atropine or glycopyrrolate for the bradycardia Placement of cotton balls in the patient’s ears and a quiet environment may alleviate signs of sound sensitivity. CHAPTER 9 / PAIN MANAGEMENT 9 389 Table 9.4 / Pain Management Drugs (Continued) 9 Nonsteroidal Anti-inflammatory Drug 390 Indications Dose/Route/Duration Comments Carprofen • Mild to moderate (severe in some cases) • Treatment of inflammation Dose • Canine: 2.2 mg/kg PO 4.4 mg/kg SQ, IM, IV • Feline: 1.2 mg/kg SQ Route • PO, SQ, IM, IV Duration • Delayed onset of 60 minutes • 12 hours (canine PO), 18–24 hours (canine SQ, IM, IV), 48–72 hours (feline SQ) • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • Give with food. Deracoxib • Mild to moderate (severe in some cases) • Postoperative orthopedic pain • Treatment and pain associated with osteoarthritis Dose • Canine, postoperatively: 3–4 mg/kg • Canine, osteoarthritis: 1–2 mg/kg Route • PO Duration • 24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • Give with food. • Give for up to 7 days postoperatively. Etodolac • Mild to moderate (severe in some cases) • Treatment of inflammation associated with osteoarthritis Dose • Canine: 10–15 mg/kg Route • PO Duration • Onset of 60 minutes • 24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • Very difficult to accurately dose canines <5 kg Firocoxib • Mild to moderate (severe in some cases) • Treatment of inflammation associated with osteoarthritis Dose • Canine: 5 mg/kg Route • PO Duration • 18–24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. Ketoprofen • Mild to moderate (severe in some cases) • Treatment of inflammation Dose • Canine/Feline: 1 mg/kg PO • Canine/Feline 1–2 mg/kg SQ Route • PO, SQ Duration • 18–24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • May mask signs and symptoms of infection • Do not use preoperatively as it may cause intraoperative bleeding. SECTION FOUR: PATIENT CARE SKILLS Table 9.4 / Pain Management Drugs (Continued) Adjuvant Nonsteroidal Anti-inflammatory Drug Indications Dose/Route/Duration Comments Meloxicam • Mild to moderate (severe in some cases) • Treatment of chronic inflammatory disease of the musculoskeletal system • Hip dysplasia or chronic osteoarthritis in Canines Dose • Canine: 0.2 mg/kg, PO on first day of treatment; then 0.1 mg/kg Q24 hr • Feline: 0.2 mg/kg, PO on first day of treatment; then 0.1 mg/kg Q24 hr for 2–4 days Route • PO Duration • 18–24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • Small canines and felines: place drops into animal’s food, not directly into the mouth. Tepoxalin • Mild to moderate (severe in some cases) • Treatment and pain associated with osteoarthritis Dose • Canine: 20 mg/kg on first dose, then 10 mg/ kg PO Q24 hours Route • PO Duration • 18–24 hours • Monitor blood values when using long term. • NSAIDs are not recommended in hypovolemic or dehydrated patients or patients with bleeding disorders or GI or renal disease. • Discontinue if vomiting or diarrhea develops. • Place the disintegrating tablet in the patient’s mouth and hold shut for 4 seconds to allow it to dissolve. Amantidine • Antiviral • NMDA antagonist • Mild to moderate chronic pain Dose • Canine/feline: 3 mg/kg Route • PO Duration • 24 hours • Used in conjunction with an opioid or NSAID to prevent or treat wind-up • Effects may not be seen for up to 1 week. Dose • Canine/feline: 1.25–10 mg/kg Route • PO Duration • 24 hours • Sedation may be seen. • Taper dose at withdrawal. Gabapentin • Anticonvulsant • Mild to moderate pain • Prevents allodynia and hyperalgesia 9 Note: Additional drug information can be found in Chapter 13 Anesthesia, page 439, and Chapter 17 Pharmacology, page 567. CHAPTER 9 / PAIN MANAGEMENT 391 PAIN MANAGEMENT TECHNIQUES Table 9.5 / Constant Rate Infusions A constant rate infusion (CRI) is the administration of a drug or combination of drugs delivered IV over an extended period of time. Drugs commonly used for CRIs are fentanyl (F), morphine (M), hydromorphone (H), lidocaine (L), and ketamine (K). The most common CRIs are FLK, MLK, HLK, an opioid alone, or lidocaine alone. Using a combination of 1 or more drugs allows for more complete analgesia with fewer side effects. This same technique is routinely used in anesthesia with superior results. Initially, a loading does is given to rapidly achieve therapeutic levels; then, a maintenance dose is started to maintain those established therapeutic levels. Avoiding the loading dose will greatly delay the amount of time for pain control to be achieved. As with any analgesic plan, pain assessments and monitoring must continue during the CRI and the plan or rate adjusted as needed to control pain. Drug Indications Compatible Fluids Rate Comments • Analgesia • ↓ Anesthetic gas requirements • 5% dextrose • Loading dose: • Canine: 2–5 μg/kg SQ, IM, IV • Feline: 1–2 μg/kg IV • Maintenance: 5–20 μg/kg/hr • Protect from light (e.g., syringes, fluid bags) • Monitor for respiratory depression. Hydromorphone • Analgesia, sedation • 0.45%, 0.9% saline • 2.5%, 5% dextrose • LRS • Loading dose (if not previously given): • Protect from light (e.g., syringes, fluid bags). • Stable in fluid bags for 24 hours • Canine: 0.1–0.2 mg/kg SQ, IM • Monitor for respiratory depression. 0.03–0.1 mg/kg IV • Feline: 0.05–0.1 mg/kg SQ, IM 0.01–0.025 mg/kg IV • Maintenance: • Canine: 0.02–0.07 mg/kg/hr • Feline: 0.005 mg/kg/hr Morphine • Analgesia • ↓ Anesthetic gas requirements • 0.45%, 0.9% saline • 2.5%, 5% dextrose • LRS • Loading dose (if not previously given): • Protect from light (e.g., syringes, fluid bags). • Use low end dose in felines to avoid • Canine: 0.5–2.2 mg/kg SQ, IM dysphoria and excitement. 0.1–0.5 mg/kg IV slowly • Monitor for respiratory depression. • Feline: 0.1–0.5 mg/kg SQ, IM 0.05–0.1 mg/kg IV slowly • Maintenance: • Canine: 0.05–0.2 mg/kg/hr • Feline: 0.025–0.2 mg/kg/hr Lidocaine • Analgesia, sedation • Cytoprotective (e.g., GDV, splenectomy) • Prevention of ileus (e.g., enterotomies) • 0.45%, 0.9% saline • 2.5%, 5% dextrose • LRS • Loading dose: 2 mg/kg IV • Maintenance: 0.6–3.0 mg/kg/hr (20–50 μg/kg/min) • Not recommended in cats • Stable in fluid bags for 24 hours • Monitor for toxicity; muscle tremors, seizures, nausea, and vomiting. Ketamine • To prevent “wind-up,” an • 0.9% saline amplification of the pain • 5% dextrose response • LRS • Enhanced analgesic effect • Loading dose: 0.5 mg/kg IV • Maintenance: 0.1–1.2 mg/kg/hr (2 μg/kg/min) • Never to be used alone • Intended to be added to an opioid Fentanyl Opioids 9 Note: Ketamine/morphine/saline bags have been shown to be stable for at least 4 days. 392 SECTION FOUR: PATIENT CARE SKILLS Skill Box 9.3 / Setting Up a Morphine/Lidocaine/Ketamine Constant Rate Infusion Method Example 1. Determine the patient’s weight in kg. 10 kg canine 2. Determine the patient’s maintenance fluid rate. Maintenance fluid rate: see Table 9.5, page 361. 400 mL/day over 24 hours = 16.5 mL/hr 3. Determine the number of hours the CRI will run based on the size of the fluid bag. 250 mL fluid bag/(16.5 mL/hr) = 15 hours 4. Calculate the amount of each drug: a. Morphine (15 mg/mL) b. Lidocaine (20 mg/mL) c. Ketamine (100 mg/mL) (0.05 mg) (10 kg) (15 hr) = 7.5 mg/(15 mg/mL) = 0.5 mL (0.6 mg) (10 kg) (15 hr) = 90 mg/(20 mg/mL) = 4.5 mL (0.1 mg) (10 kg) (15 hr) = 15 mg/(100 mg/mL) = 0.15 mL 5. Remove as much fluid from the IV fluid bag to equal the amount of drugs to be added. (0.5 + 4.5 + 0.15) = 5.15 mL 6. Add drugs to IV fluid bag. 7. Label bag with the name of each drug, concentration, amount added, date, time, and patient’s name. Tip: To allow easy adjustment of the fluid rate without the risk of overhydration or dehydration, piggyback the CRI drugs into the main fluid line via another fluid bag or a syringe pump. Tip: CRIs containing an opioid or lidocaine can be protected from light by being wrapped with a dark towel, material, or bandaging material. 9 CHAPTER 9 / PAIN MANAGEMENT 393 Chapter 10 Wound Care Wound Treatment and Bandaging 396 Wound Healing Process 396 Classification of Wounds 397 Factors Affecting the Healing Process 398 Wound Care 399 Wound Cleaning Solutions 401 Topical Wound Medications 402 Wound Bandaging 403 Bandage Care 404 Bandaging 405 Basic Bandage 405 Robert Jones Bandage 406 Chest/Abdominal Bandage 407 Distal Limb Splint 408 Casts 408 Ehmer Sling 409 90–90 Flexion 410 Velpeau Sling 410 Hobbles 411 10 395 Key Words and Termsa Adherent Autolytic Degloving Dehiscence Edematous Epithelialization Exudate Fibroblasts Granulation bed Hydrophilic Lavage Macrophages Necrotic Onychectomy Sequestra Serosanguineous Viscous a Abbreviations Additional Resources, page DL, deciliter EDTA, ethylenediaminetetraacetic acid g, gram LRS, lactated Ringer’s solution mm, millimeter NaCl, sodium chloride SSD, silver sulfadiazine U, units Commonly used fluids, 363 Disinfectants, 627 Surgery, 521 Ultrasound, 197 Key words and terms are defined in the glossary on page 631. WOUND TREATMENT AND BANDAGING Inevitably, pets end up with wounds, either self-inflicted or caused by another source. These wounds may be intentional, such as a surgical incision, or an accident. A technician plays a valuable role in the setup, preparation, cleaning, and the actual bandaging of these wounds. An under- standing of the wound healing process, supplies to use, and the expected final outcome is necessary for proper treatment and care. These items are included in this chapter to facilitate excellent nursing care by the technician. 10 Table 10.1 / Wound Healing Process The wound healing process is not a stationary process; several phases occur simultaneously with subtle transitions. The rate and quality of the healing are dependent on many factors, such as nutritional status, current medications (e.g., steroids, cytotoxic drugs), infection, and additional treatments (e.g., radiation). Inflammatory 䉴 1. Hemorrhage cleans the wound and begins to provide cells necessary for debridement. 2. Vasconstriction is in first 5–10 minutes, allowing the small vessels to clot. 3. Vasodilation permits the leakage of plasma and protein necessary for clotting. 4. Neutrophils leak out (∼6 hours after initial trauma) to engulf and remove bacteria and necrotic tissue. 5. Monocytes fill the wound (∼12 hours after initial trauma) and participate in tissue formation remodeling. 6. Monocytes become macrophages (∼24–48 hours after initial trauma) and continue to remove bacteria, foreign material, and necrotic tissue. 396 SECTION FOUR: PATIENT CARE SKILLS Repair 䉴 Wound Contraction 䉴 Maturation 7. Fibroblasts and new capillaries fill the wound, producing granulation tissue (∼3–5 days), which protects the wound from infection and provides a surface for the attachment of epithelial cells to connect the 2 sides of the wounds. 8. New epithelial cells reproduce at wound edge, covering the granulation bed and resulting in a scab. 9. Fibroblasts pull together the wound edges at ∼0.6–0.8 mm/ day (∼5–9 days after initial trauma). 10. Remodeling of fibrous tissue strengthens the scar and reduces the scab (begins ∼4 weeks after initial trauma). 11. Scar may continue to gain strength for years but will always be 15– 20% weaker than surrounding tissue. Table 10.2 / Classification of Wounds Classification Characteristics Tissue Integrity Open • Lacerations or skin loss Closed • Crushing injuries and contusions Etiologic Force Abrasion • Loss of epidermis and portions of dermis. Usually attributable to shearing between 2 compressive surfaces or friction from blunt trauma Avulsion • Tearing of tissue from its attachment and the creation of skin flaps • Avulsions with extensive skin loss on extremities are degloving injuries. • Forces similar to those causing abrasion but of greater magnitude Burns • A partial- or full-thickness skin injury caused by heat or chemicals Incision • Created by a sharp object • Wound edges are smooth, and minimal tissue trauma is present in surrounding tissue. Laceration • Irregular wound caused by tearing of tissue with variable damage to superficial and underlying tissue Puncture • Skin penetration by a missile or sharp object • Superficial damage may be minimal, but damage to deeper structures may be considerable. • Contamination by hair and bacteria with subsequent infection is common. Degree of Contamination and Duration Class I • Zero to 6 hours; duration with minimal contamination Class II • Six to 12 hours; duration with significant contamination Class III • Twelve hours; duration or longer with gross contamination 10 Degree of Contamination Clean wound • Surgically created under aseptic conditions. No invasion of respiratory, alimentary, or genitourinary tracts or of the oropharyngeal cavities. Clean contaminated • Minimal contamination and contamination can be effectively removed. Includes operative wounds involving the respiratory, wound alimentary, and genitourinary tracts. Contaminated wound • Open traumatic wound with heavy contamination and possibly foreign debris. Includes operative wounds with major breaks in aseptic technique, and incisions in areas of acute nonpurulent inflammation adjacent to inflamed or contaminated skin. Dirty/infected wound • Old traumatic wounds and wounds with clinical infection or perforated viscera Adapted from Steven F. Swaim and Ralph A. Henderson Jr: Small Animal Wound Management, 2nd ed, Chapter II, page 14. Baltimore, 1997, Lippincott Williams and Wilkins. CHAPTER 10 / WOUND CARE 397 Table 10.3 / Factors Affecting the Healing Process Factor 10 Effect on Healing Blood Supply • Blood supply is responsible for the delivery of oxygen and metabolic substrates that promote wound healing. • Dehydration, trauma to the area, tight bandages, or location of the wound may have an effect on this factor. • Certain stages (e.g., epithelialization) of wound healing are oxygen dependent and require optimal blood supply. Dead Space • Separation of tissue can result in fluid accumulation (e.g., seromas), producing a hypoxic state impairing cell migration. • Fluid accumulation mechanically inhibits adhesion (e.g., flaps and grafts) to the granulation bed. • Sutures and drains reduce the dead space. Diseased or Debilitated Patients • Diseased, debilitated, or stressed organs hinder the healing process. • Delayed wound healing with diabetes, hepatic disease, hyperadrenocorticism, neoplasia, and uremia. • Geriatrics often heal slower, potentially due to concurrent disease or debilitation. Foreign Material • Foreign material (e.g., foreign debris or suture material) results in prolonged inflammatory phase of healing and ↑ risk of infection. Hemostasis • If bleeding is not stabilized effectively, a seroma or hematoma may form. • Extra fluid in a wound slows down the healing process as the body must reabsorb and breakdown old blood and fluid during the inflammatory phase. • Can predispose wound to sepsis Infection • Overgrowth of bacteria prolongs the inflammatory phase and may lead to a systemic infection (sepsis). Medications • • • • • Moisture • A moist environment allows for optimal healing. • Allows for cell migration and subsequent healing, ↑ rate of epithelialization, and limits infection and penetration of topical medications. • Bandaging helps to keep a wound warm and moist. Necrotic Tissue • Dead tissue prolongs the inflammatory phase and predisposes the animal to sepsis. Nutrition • Malnutrition and serum albumin <1.5–2.0 g/dL delay wound healing and diminish wound strength. • Vitamin supplementation (e.g., vitamins A and E) and aloe vera can ↑ wound healing. 398 Medications may inhibit connective tissue building and epithelial cell turnover rate. Corticosteroids delay the entire wound healing process and ↑ the risk of infection. Aspirin may affect blood clotting during early phase of wound healing. Anti-inflammatory drugs affect inflammation. Chemotherapeutic drugs and radiation can drastically inhibit wound healing (e.g., postoperative interval 10–14 days desirable between surgery and adjunct antineoplastic treatment). SECTION FOUR: PATIENT CARE SKILLS Skill Box 10.1 / Wound Care Care for an open or superficial wound should begin immediately after trauma. The wound should be covered with a clean, dry cloth or bandage to prevent further hemorrhage or contamination. Ideally, wounds should be treated within the first 6–8 hours before bacterial contamination has multiplied and the wound becomes infected. Infected wounds, rather than contaminated wounds, are often covered with a thick, viscous exudate and visually appear dirty. Before any procedure involving wound care, gloves should be worn by those in contact with the wound because bacteria may be translocated to the wounds. Setup • • • • Chlorhexidine solution Suture material Clippers Sterile water-soluble lubricant • Wound cleaning fluids • Surgical instruments (e.g., hemostats, needle holder, scissors, thumb forceps) • Gloves Tip: Scissors dipped in mineral oil can be used so that the hair will stick to the scissors. Step I: Wound Preparation 1. Clean out any large, obvious debris. 2. Protect the wound from further contamination (e.g., water-soluble lubricant [K-Y Jelly], saline-soaked gauze, or temporarily close with sutures, clamps, or staples). 3. Remove the hair from around the wound with scissors or clippers. 4. Prepare the clipped skin as a surgical prep; avoid using alcohol. 5. Remove the wound protectant (e.g., water-soluble lubricant [K-Y Jelly], saline-soaked gauze, or temporarily close with sutures, clamps, or staples). Step II: Wound Cleaning • Lavage the wound to reduce the bacterial count and remove additional contaminants and necrotic debris. Lavage Solutions • Warm, balanced electrolyte solutions (e.g., LRS), sterile saline, or tap water • See Table 8.9 Commonly Used Fluids, page 363. Lavage Method • Intravenous administration set with a 3-way stopcock attached to the syringe and needle. • A 30–35 mL syringe with 18–19 gauge needle. • Use moderate pressure to thoroughly clean the wound, all debris should be removed 10 Step III: Wound Debridement • Autolytic: maintaining a moist environment with hydrophilic, occlusive, or semiocclusive bandaging • Bandage: wet-to-dry and dry-to-dry bandages allowed to adhere to the wound surface and when top layers when removed; not highly recommended due to unselective debridement and damage during the proliferative stage of wound healing • Biosurgical: sterile medicinal maggot therapy to remove necrotic tissue, disinfect, and promote granulation • Enzymatic: agents used to break down necrotic tissue • Surgical: excision of devitalized tissue (e.g., skin, muscle, contaminated fat) and bone sequestra CHAPTER 10 / WOUND CARE 399 Skill Box 10.1 / Wound Care (Continued) Step IV: Wound Closure Type of closure is dependent on time lapse, degree of contamination, tissue damage, thoroughness of debridement, blood supply, animal’s health, closure without skin tension or dead space, and location of wound. Primary Wound Closure • First intention wound healing, wound is sutured closed • Used when wounds are 6–8 hours old, with minimal tissue damage and minimal contamination or cleaned wounds Contraction and Epithelialization • Second intention wound healing, wound is left to heal open with epithelialization and skin defect contraction over time (days to week) • Used when wounds are ≥5 days old, have significant tissue damage and loss, or are excessively contaminated • Allows gradual debridement and drainage; new skin may not contain hair follicles Delayed Primary Closure • Third intention wound healing, wound is sutured closed after the granulation tissue has formed • Used when wounds are 3–5 days old and are heavily contaminated or infected • Allows controlled debridement and optimal drainage Drain Placement • Used to eliminate dead space and provide drainage of potentially harmful fluids (e.g., blood, pus, serum) • Passive drains (e.g., Penrose drains) allow drainage by gravity and are most commonly used for subcutaneous spaces • Active drains allow drainage with an intermittent or continuous negative pressure that is either open or closed to the environment and are most commonly used for deep wounds and after grafting of skin. • Ascending infection is the most common complication of drains (especially Penrose drains) and should therefore be covered with a sterile dressing; change as needed. 10 Step V: Postoperative Care and Assessment Monitoring • Visual inspection for fluid accumulation, tension, infection, dehiscence, and necrosis • Ultrasound evaluation for fluid accumulation, scar formation, granulation tissue, blood clots, edematous regions, and epidermis Drain Care • Monitor for drainage as tissue fragments, viscous exudate, or fibrin may occlude the tube. • Apply hot compresses to the drainage area 2–3 times daily to improve drainage and to keep passive drainage sites open. • Typically removed in 3–5 days, but may be needed for up to 14 days Suture Care • Keep dry. • Suture removal is 7–14 days; with longer use, suture material will become a foreign material. 400 SECTION FOUR: PATIENT CARE SKILLS Table 10.4 / Wound Cleaning Solutions Solution Comments 0.9% NaCl • Grossly contaminated, burns, lacerations, dermal ulcers and abrasions • Isotonic solution • No antimicrobial activity Balanced Electrolyte Solution • Grossly contaminated, burns, lacerations, dermal ulcers and abrasions • Ideal isotonic solution that is the least cytotoxic • No antimicrobial activity Tap Water • Grossly contaminated and lacerations • Not an ideal solution, but can be used as an initial treatment to lavage severely contaminated wounds • Hypotonic and can cause cell swelling, leading to destruction and delayed wound healing • No antimicrobial activity Chlorhexidine • Nolvasan • Grossly contaminated, burns, lacerations, dermal ulcers, abrasions • Wide spectrum of antimicrobial activity and residual activity for up to 2 days • Promotes rapid healing with minimal systemic absorption and toxicity even in the presence of blood and organic debris • A 0.05% solution (1 mL chlorhexidine 2% + 39 mL LRS) is recommended as higher concentrations may lead to ↓ wound healing and tissue slough. • Precipitates in LRS and NaCl, causing no detriment to wound care • Complications: resistance in some bacteria, corneal drying and synovial inflammation with joint lavage Chloroxylenol • Technicare • All wound care • Effective against all gram-negative and gram-positive organisms within 30 seconds, antiviral and antifungal • Apply to wound and gently scrub with a gauze sponge for 2 minutes to cleanse and stimulate antimicrobial action and rinse. • Safe and effective for mucous membranes and around ears and eyes • Do not leave in wound bed. (e.g., LRS, Normosol) Wound Lavage and Cleaning Indications 10 Povidone-Iodine • Betadine • Grossly contaminated • • • • Wide spectrum of antimicrobial activity and residual activity for 4–8 hours A 0.1% solution (1 mL povidone-iodine + 99 mL LRS) is recommended. Scrubbing of wounds can damage tissues and ↑ infections. Complications: intensify metabolic acidosis, excessive systemic iodine, inactivated by organic debris and contact hypersensitivities Tris-EDTA • Otitis externa, abscess, rhinitis, cystitis • Formulated by adding Tris-EDTA, sodium hydroxide to a solution (e.g., sterile water, chlorhexidine) and autoclaving or a commercially available formula (e.g., trizEDTA, T8 solution) • Keeps solution slightly basic and allows entry of antibiotics through the cell wall of gram negative bacteria, leaving them more susceptible to destruction. CHAPTER 10 / WOUND CARE 401 Table 10.5 / Topical Wound Medications The use of topical medications allows direct contact of the medication with the wound bed. While each topical medication has its benefits, they can also cause deleterious effects (e.g., cytotoxicity, delaying epithelialization), and care should be taken when choosing the medication. Topical medications used on wounds heavily contaminated will not be able to penetrate the deeper tissues; therefore, the wound should be debrided and cleaned prior to use. Antibacterial Hydrophilica Promotes Promotes Comments Granulation Epithelialization Medication Indications Acemannan • Burns, lacerations, dermal ulcers, abrasions, nonhealing wounds Aloe Vera • Burns, fungal infections X X D-Glucose • Contaminated and X infected wounds X Polysaccharide X Gentamicin Sulfate • Grafted wounds (preoperative and postoperative) X Honey (Raw, Unpasteurized) and Sugar • Avulsions, bedsores, frostbite X Ketanserin • Impaired circulation, peripheral sites Nitrofurazone • Lacerations, dermal ulcers, abrasions X Silver Sulfadiazine (SSD) • Burns, necrotic wounds X Triple Antibiotic Ointment • Lacerations, dermal ulcers, abrasions X X X • Derived from the aloe vera plant • Used during the early inflammatory stages of healing • Excessive granulation may be seen, which inhibits wound contraction. X • Counteracts inhibitory effects of SSD • Antibacterial activity against Pseudomonas X • Daily bandage change and application necessary • Isotonic solutions are preferred. • Inactivated by purulent exudate X X • Enhances debridement, granulation bed formation, epithelialization, improves wound nutrition, reduces edema and inflammation, and is antibacterial-like • After the wound is clean of exudate (3–4 days), honey or sugar is applied to the nonadherent layer and bandaged as usual. • Change bandage daily until granulation bed established and exudate decreases, then every 1–2 days. X • Not for use in deep or infected wounds or immediately following surgery • Twice-daily treatment 10 a X • Delays epithelialization X Hydrophilic properties help cleanse the wound and reduce wound edema by pulling fluids through the wound into the bandage. 402 SECTION FOUR: PATIENT CARE SKILLS • Effective against most gram-positive, gram-negative, and fungi • Ointments effective for 3 days and dressing effective for 7 days • Combined with insulin (100 U insulin, 1 oz SSD) for burn treatments • Ability to penetrate eschar and necrotic tissue • • • • • Bacitracin, neomycin, polymyxin Anaphylactic reactions (feline, rare) Poor activity against Pseudomonas Not very effective on infected wounds Poor absorption by the tissues Table 10.6 / Wound Bandaging Wound healing is a process involving many different stages, each requiring a specific environment for optimal results. Bandaging most often can provide the changing environment needed for each stage. Bandaging provides cleanliness, immobility, control of wound environment, elimination of dead space, hemostasis, decreased edema and pain, moisture, and warmth. Bandaging can also increase the acidity of the wound environment, resulting in an increase in oxygen dissociation from hemoglobin, thereby increasing oxygen to the wound, which promotes healing. The patient should be more comfortable after bandage placement. A patient that is very upset with a bandage should be evaluated for incorrect bandage placement, skin irritation, or worsening of the wound. Some keys to successful bandaging are: • Pressure should be applied over and distal to the wound, as proximal pressure will impede blood and lymphatic return with subsequent swelling and edema. • Avoid wrinkles in the bandaging material, as these may become areas of discomfort. • Ensure the area to be bandaged (e.g., surrounding skin, hair, between toes) is dry, as these areas may develop moist dermatitis. • Almost all bandages and splints should be applied with the limb in a normal functional angle, as seen when the animal is at rest in lateral recumbency. Bandage Layer Purpose Material Type Comments Primary • Protect the wound and in some cases for debridement • See below • Should remain in contact even during movement • Gauze pads, cling gauze • Not highly recommended due to unselective debridement and damage during the proliferative stage of wound healing • Dry gauze is placed over wound and bandaged. • Painful to remove, rewetting the gauze with warm saline may facilitate removal • Change: daily (Contact Layer) Adherent: promote debridement in the inflammatory stage • Dry/Dry • Absorbs exudate, necrotic tissue, and foreign material • Debris adheres to the material and is removed with bandage change • Wet/Dry • Loosens dried exudate, necrotic tissue, and foreign material by rehydration of wound • Absorbed by the secondary layer • Gauze pads or cling gauze soaked in saline or 0.05% chlorhexidine • Not highly recommended due to unselective debridement and damage during the proliferative stage of wound healing • Dry gauze is placed over wound, soaked, and bandaged. • Painful to remove, rewetting the gauze with warm saline may facilitate removal • Disadvantage: bacterial proliferation and strike through • Change: daily • Film or Skin Sealant • Provide a barrier to the wound surface from bacteria, water, environmental contaminants (e.g., urine, feces) • Transparent liquid • May be used alone or bandaged • Change: every 3–4 days Nonadherent: promote moisture retention and epithelialization with minimal disruption of granulation bed • Switched from adherent dressing when granulation bed is forming and drainage is serosanguineous, typically 3–5 days • Occlusive • Used when no exudate is present; in the repair stage • Hydrocolloid dressing; hydrogel, hydrophilic beads, polyurethane films • Impermeable to air, which can lead to trapping excessive moisture and subsequent skin damage • Change: 2–7 days, dependent on product CHAPTER 10 / WOUND CARE 403 10 Table 10.6 / Wound Bandaging (Continued) • Semiocclusive • Prevents tissue dehydration, but allows fluid absorption • Telfa pads, gauze coated with petrolatum, polyethylene glycol, petrolatum-based antibiotic ointment, calcium alginate • Used once epithelialization begins • Change: 1–3 days, dependent on product • Foam • To protect the wound from further impacts and trauma • Promote moist wound environment and autolytic debridement • Polyurethane foam, hydrosorb • • • • Secondary Layer (Intermediate Layer) • To protect the wound from further • Heavy padding: rolled cotton • Enough pressure needs to be applied to avoid spaces between the impacts and trauma and draw away • Moderate padding: cast wound, primary layer, and secondary layer. and store heavy secretions and padding • Excessive pressure impairs blood supply and impairs wound healing exudates • Light padding: stretch bandage (e.g., contraction). • Thickness is determined on the expected amount of drainage to absorb. Tertiary Layer (Outer Layer) • To provide consolidation of the secondary layer • Stretch gauze Protective Layer • To protect the bandaging from outside contamination • Apply pressure, conform and immobilize the bandage • Elastic wrap (Coban, VetWrap) • Can create an occlusive bandage leading to trapped excessive • Adhesive tape moisture and subsequent skin damage Nonadherent to wound surface, but adhesive to surrounding skin Can be used dry or moistened with saline or medications Used for all types of wounds, cut to fit Change: 1–5 days • Enough pressure needs to be applied to avoid spaces between the wound, primary layer, secondary layer, and tertiary layer. • Excessive pressure impairs blood supply and impairs wound healing (e.g., contraction). • Splints and supports are incorporated into the tertiary layer. 10 Skill Box 10.2 / Bandage Care 1. Bandage should be checked daily for slippage, wetness, and odor. 2. Wet bandages should be changed immediately to avoid skin and wound damage. 3. Bandage should be kept clean and dry. A plastic bag should be place when outside, but should be removed within a 30-minute period to reduce buildup of moisture. 4. Chewing the bandage should be controlled with an Elizabethan collar, foul-tasting spray, or other measures to avoid causing further damage. 5. Monitoring of the toes for warmth, color, swelling, and foul odor should be done twice daily. 6. Follow instructions of the veterinarian for bandage changes and removal. 404 SECTION FOUR: PATIENT CARE SKILLS BANDAGING Skill Box 10.3 / Basic Bandage Usage: Bandaging of basic wounds and incisions 1. Place 2 adhesive tape strips on either side of the wound from where you expect the bandage to start to the distal portion of the limb to prevent slippage. Tip: A tongue depressor may be placed at the distal end to temporarily adhere the tape ends and to avoid entangling. Tip: Apply tape laterally when wound is at the distal end of the extremity (e.g., onychectomy, toe amputation). Tip: Small pieces of cotton or gauze can be placed in depressions (e.g., between toes, metatarsal-metacarpal pad) to smooth out bandaging area. 2. Apply primary bandage layer over the wound. 3. Apply secondary bandage layer starting 2/3 up from the expected bottom of the bandage such that the layers overlap one another by 50% and are taut, but not constricting. Place extra padding over the depression areas and be careful not to permit wrinkles. Toes can be covered to inhibit edema (the secondary layer is brought over the toes dorsal to ventral and then reflected back, ventral to dorsal) or can be left exposed to check on temperature of limb, permit drainage of fluids, and permit assessment of the healing environment (wrap the secondary layer obliquely at the distal end to keep the 3rd and 4th digits exposed). 4. Place 1 layer of tertiary bandage layer (as described in Step 3), twist and reflect adhesive strips back over this layer, and finish with final layer of tertiary bandage. 5. Place protective layer of elastic wrap (as described in Step 3). 6. Place adhesive tape around top of bandage, partially adhering to fur and covering the bottom of bandage for reinforcement of the toe area. Tip: Always end the bandage at the bottom of the area to alleviate pressure. CHAPTER 10 / WOUND CARE 405 10 Skill Box 10.4 / Robert Jones Bandage Usage: Temporary immobilization of fractures below the stifle or elbow joint before or after surgery by providing rigid stabilization. (Remove after 1 day.) 1. Place 2 adhesive tape strips on either side of the wound from where you expect the bandage to extend to the distal portion of the limb. 2. There is no primary layer unless sutures or wounds are present; then a nonadherent dressing can be placed. 3. While maintaining normal flexion of the limb, wrap thick roll cotton (4–6 inches thick) around the limb from mid femur/mid humerus to toes to constitute the secondary layer. 5. Twist and reflect adhesive strips back over the secondary layer. 6. Place protective layer of elastic wrap as the tertiary layer. 7. Place adhesive tape around the top of the bandage, partially adhering to fur and around the bottom of the bandage for reinforcement. 10 4. Compress with at least 2–3 layers of a conforming gauze (3–4 inches wide) secondary layer. Apply sufficient compression on the conforming gauze throughout application to achieve a smooth, even tension. Tip: A well-applied Robert Jones bandage should make a dull thudding sound when tapped. Alternative: Modified Robert Jones bandage is placed following the instructions above while using <½ of the cotton padding to place a less bulky bandage. Their use is to reduce postoperative swelling of a limb. 406 SECTION FOUR: PATIENT CARE SKILLS Skill Box 10.5 / Chest/Abdominal Bandage Usage: To control abdominal bleeding (effective for 1–2 hours and should be removed before 4 hours) and cover and protect wounds, surgical incisions, or drains. 1. Apply primary bandage layer over the wound if necessary. 3. Apply tertiary layer around the torso, then through the legs and over the shoulders in a crisscross fashion (or figure of 8) to prevent slippage. 4. Place protective layer of elastic wrap. 5. Place adhesive tape around the cranial aspect of the bandage, partially adhering to fur. 2. Apply secondary bandage layer, starting mid thorax such that the layers overlap one another by 50% and are taut but not constricting. The bandage should extend to the pelvis. On male dogs, be sure to leave the animal’s prepuce exposed. Care must be taken to ensure that the bandages are not too tight so as to restrict thoracic movement. The amount of secondary layer is determined by the expected amount of drainage. 10 CHAPTER 10 / WOUND CARE 407 Skill Box 10.6 / Distal Limb Splint Skill Box 10.7 / Casts Usage: Temporary immobilization or definitive stabilization for distal extremity fractures or luxations. Usage: for stabilization of simple fractures and immobilization of limbs (typically for 4–5 weeks). 1. Place 2 adhesive tape strips on either side of the wound from where you expect the bandage to extend to the distal portion of the limb. 2. Apply primary bandage layer over the wound or suture line if necessary. 3. While maintaining normal flexion of the limb firmly wrap secondary bandage layer (e.g., cast padding) around the limb to 1 inch above the proximal end of the splint. Apply enough material to cover bony prominences to ensure comfort from pressure sores and abrasions, while limiting material bulk. 4. Apply a conforming gauze tertiary bandage layer, compressing the secondary bandage layer. Place the appropriate-sized splint on the caudal aspect of the limb, ensuring there are no gaps between the tertiary layer and splint. Twist and reflect adhesive strips onto the splint. Continue with a final layer of the tertiary layer. 1. Have a bowl of hot water ready for the cast material and examination gloves ready for the application process. 2. Place 2 adhesive tape strips on either side of the wound or incision line from where you expect the bandage to start to the distal portion of the limb. 3. Apply a stockinette as a primary layer (smooth with wrinkles). 4. Apply secondary bandage layer, starting 2/3 up from the expected bottom of the bandage such that the layers overlap one another by 50% and are taut but not constricting. Pad the prominences on the leg, not the depressions. Toes can be covered to inhibit edema or they can be left exposed to check on temperature of limb, permit drainage of fluids, and permit assessment of the healing environment. 5. The cast material is used as the tertiary layer. Cast materials vary, and manufacturer’s guidelines should be followed. 6. Twist and reflect adhesive strips and stockinette edges back over the top layer of the cast material. 7. Protective tape is applied over the ends of the cast. 10 5. Place protective layer of elastic wrap. 6. Place adhesive tape around top of bandage, partially adhering to fur and covering the bottom of bandage for toe reinforcement. 408 SECTION FOUR: PATIENT CARE SKILLS Skill Box 10.8 / Ehmer Sling Usage: Immobilization of the hindlimb after reduction of a craniodorsal coxofemoral luxation and prevention of weight bearing after pelvis surgery (change: 5–7 days). 1. Place minimal padding on the metatarsal area using secondary layer material. 2. Using 2-inch adhesive tape, wrap the tape around the medial aspect of the metatarsal, and attach the tape end to the tape roll. Continue medially around the flank and back around the metatarsus. Keep the limb with stifle and hock in maximum flexion for 1–2 passes. 3. On the next pass, go around the flank and twist behind the hock. 4. Pass over the front of the metatarsal area. 5. Repeat Steps 3 and 4 for 3–4 passes. 10 Note: Correct application results in the internal rotation and adduction of the coxofemoral joint. Alternative: Use gauze in place of adhesive tape followed by a final layer of elastic adhesive. CHAPTER 10 / WOUND CARE 409 Skill Box 10.9 / 90–90 Flexion Usage: After distal femoral fracture surgery in young patients and for prevention of weight bearing after hindlimb surgeries. 2. Bandage the forelimb in same manner, keeping the foot exposed, and pad the depressions of the limb. 1. Stifle and hock are in a 90˚ flexion. No attempt to adduct or internally rotate the coxofemoral joint is made. 2. Place minimal padding on the metatarsal area. 3. Same as for Ehmer sling, Step 2. 4. The tape is passed horizontally around the tibia to hold the layers in place. 10 3. Gently flex the forelimb against the chest wall and attach adhesive tape (2–4 inches wide) around the chest and flexed forelimb, creating a sling. Skill Box 10.10 / Velpeau Sling Usage: Holds flexed forelimb against the chest; non–weight-bearing sling for the forelimb; reduction of scapulohumeral joint luxation; immobilization of a scapular fracture. 1. Cover the chest wall and shoulder with a lightly padded secondary layer and gauze tertiary layer. 410 SECTION FOUR: PATIENT CARE SKILLS Skill Box 10.11 / Hobbles Usage: To prevent excessive abduction of the hindlimbs; specifically indicated after reduction of ventral coxofemoral luxation; to relieve excessive tension in the inguinal region; to prevent excessive activity after pelvic fracture repair, or nonsurgical, conservative management of pelvic fractures. 1. Stand the animal with the hindlimbs equal distance to the width of the pelvis. 2. Pass the adhesive tape (which needs to be wide enough to cover half of the metatarsal area) around the 2 limbs. Press the tape together in the area between the 2 limbs. 10 CHAPTER 10 / WOUND CARE 411 Chapter 11 Parenteral Nutrition Nutritional Support 414 Tips on Encouraging Oral Nutrition 414 Enteral Nutrition 414 Coax Feeding and Orogastric Tube 414 Nasoesophageal/Nasogastric Tube 415 Esophagostomy Tube 417 Gastrotomy Tube Without Gastropexy 418 Gastrotomy Tube With Gastropexy 419 Jejunostomy Tube 420 Enteral Nutrition Administration 421 Parenteral Nutrition 422 Parenteral Nutrition 423 Parenteral Nutrition Administration 424 Worksheet for Calculating Total Parenteral Nutrition (TPN) 425 Worksheet for Calculating Peripheral or Partial Parenteral Nutrition (PPN) 426 11 Key Words and Termsa Aborally Amino acid Carbohydrate Celiotomy Cellulitis Dehiscence Epistaxis Fat Hyperosmolar Isosmolar Kilocalorie a Abbreviations Lipid Malassimilation Minerals Percutaneous Peristomal Perivascular Pneumoperitoneum Protein Refeeding syndrome Thrombocytopathia Vitamins μ, micro BUN, blood urea nitrogen BW, body weight CRI, constant rate infusion Fr, French g, gram GDV, gastric dilatation volvulus GIT, gastrointestinal tract hr, hour kcal, kilocalorie kg, kilogram Additional Resources, page lb, pound mL, milliliter mOsm, milliosmoles PCV, packed cell volume PER, partial energy requirement PN, parenteral nutrition PPN, partial or peripheral nutrition PVC, polyvinyl chloride RER, resting energy requirement TPN, total parenteral nutrition Catheter placement, 349 Constant rate infusions, 392 Drug administration, 348 Fluid therapy, 359 Nutrition, 57 Patient monitoring, 332 Suture techniques, 548 Key words and terms are defined in the glossary on page 631. 413 NUTRITIONAL SUPPORT Many hospitalized patients are at risk of becoming severely malnourished because they lack the desire or ability to eat. In response to injury and illness, the body breaks down protein, depleting the body’s protein stores. Providing protein, carbohydrate, fat, and other nutrients slows the breakdown of lean body mass and optimizes the patient’s response to therapy. Injuries and illnesses can further increase a patient’s caloric requirement, making nutritional support even more crucial. There are many ways to provide this support, both enterally and parenterally. The following will give basic guidelines for choosing the correct method and administration protocols. Skill Box 11.1 / Tips on Encouraging Oral Nutrition Hospitalized patients, for many reasons, whether physical or emotional, choose not to eat while in our care. Sometimes, with a small amount of our time and energy, their appetites can be stimulated and their moods improved, leading to an empty dinner plate. This effort can often save the patient from having to endure enteral or parenteral nutritional support. Unless contraindicated by an illness or injury, this approach should always be tried first. Environment • If possible, move the patient to a quiet area, away from barking dogs and loud noises. • Spray the environment with feline facial pheromones (feline). • Try various shapes and types of bowls; plastic may have a strange smell (feline). Patient • Make sure the patient is capable of oral intake. • Hand-feed or pet the animal during feeding. • Make sure the nasal passages are clear of exudate to allow sufficient olfactory senses. Diet • • • • • • Warm the food; stir the food well before feeding to avoid hot spots. Add water to either dry food (to moisten) or to canned food (to make a slurry). Use top dressings such as baby food or canned food. Use foods that have a strong odor or flavor. Offer a variety of foods with differing flavors and textures, both canned and dry. Specific situations may benefit from the administration of short-term appetite stimulants: cyproheptadine, diazepam. Enteral Nutrition 11 Enteral nutrition is the preferred way of providing nutrition. Providing nutrition to some portion of the gastrointestinal tract allows for the health and integrity of the tract to remain. Prolonged periods of nonuse contribute to its mucosal barrier failure and systemic bacterial contamination. Patients that are unable or unwilling to eat at least 85% of their RER but are able to digest and absorb nutrients in the small intestines should be provided nutrition by this route. Depending on the patient’s medical condition, there are many options of providing enteral nutrition. Skill Box 11.2 / Enteral Nutrition: Coax Feeding and Orogastric Tube Method Coax Feeding Orogastric Tube Advantages • Noninvasive • Ease of procedure • Minimal patient stress • Ease of procedure • Rapidly deliver high quantities Disadvantages • Patient tolerance • Difficult to meet caloric needs • May lead to learned food aversion • • • • 414 SECTION FOUR: PATIENT CARE SKILLS Patient tolerance ↑ Restraint and stress on patient Aspiration Repeated intubation; trauma Skill Box 11.2 / Enteral Nutrition: Coax Feeding and Orogastric Tube (Continued) Indications • Partial anorexia • Partial anorexia in neonates Contraindications • Patients with difficulty swallowing • Neonates with disorders of the oral cavity, pharynx, larynx, or esophagus Setup • 12-mL curved tipped syringe • High-calorie canned diet, ± blended with water to facilitate passage through the syringe tip • • • • • Procedure Cut the end of the curved tip syringe about ¼–1/3 inch to allow easier passage of food. Insert the syringe between the molar teeth and cheek (canine) or between the canine teeth (feline) of the patient’s mouth positioned toward the back of the mouth. Slowly begin filling the mouth according to the speed of swallowing while allowing breaks to breathe. Feeding should be stopped if patient does not swallow food voluntarily. Measure the feeding tube from the tip of the nose to the last rib and mark with a permanent marker. Lubricate the end of the tube and position the patient’s head in a slightly flexed position. Begin inserting the tube into the patient’s mouth, allowing them to swallow the tube. Continue to insert tube until the premeasured mark. Confirm proper placement by checking for negative pressure, injecting 3–5 mL of sterile saline into the tube, which will elicit a cough if placed in the airway, or placing 5–10 mL of air into the tube and auscultating for borborygmus at the xyphoid. Administer diet and then remove the tube by bending in half to occlude and pulling in a downward direction to prevent backflow. Complications • Aspiration • Vomiting • Patient biting tube into pieces • Endotracheal placement: kittens do not have a gag reflex, allowing easy endotracheal intubation and aspiration • Vomiting Removal 3.5–8 Fr feeding tube High-calorie diet that has a texture allowing easy flow through the tube Lubricant Mouth speculum Permanent marker • Immediately following each procedure • Kink tube and gently, but briskly remove the tube to avoid fluid aspiration 11 Skill Box 11.3 / Enteral Nutrition: Nasoesophageal and Nasogastric Tube Method Nasoesophageal/Nasogastric Tube Advantages • • • • • • Disadvantages • Size restriction of tube • Need for a liquid or highly blended diet Indications • Any patient experiencing malnutrition and/or anorexia Easy placement and removal Patient tolerance Placement without general anesthesia Removal of gastric air and fluid from the esophagus and stomach by suction (e.g. post GDV and megaesophagus) Patient can eat and drink around the tube. Tube removal can be performed anytime after placement. CHAPTER 11 / PARENTERAL NUTRITION 415 Skill Box 11.3 / Enteral Nutrition: Nasoesophageal and Nasogastric Tube (Continued) Contraindications • Patients undergoing oral, pharyngeal, esophageal, gastric, or biliary tract surgery • Patients with esophageal disorders or reflux, vomiting, regurgitation, megaesophagus, thrombocytopenia/thrombocytopathia, or nasopharyngeal trauma • Patients who are unconscious or recumbent • Patients who are hypothermic or hypotensive Setup • • • • • • Procedure Place 2 (0.5–1 mL) applications of local anesthetic in the nasal cavity by tilting the head up to encourage coating of the nasal mucosa. Select proper tube size and measure from the nares to the 7th or 8th intercostal space for nasoesophageal placement or the last rib for nasogastric placement and mark with tape. Lubricate the end of the tube with 5% viscous lidocaine and hold the head in a normal functional position; avoiding hyperflexion or hypoflexion of the neck. Gently and briskly insert the tube ventrally and medially. The tube will drop into the oropharynx and stimulate a swallowing reflex. Pass the tube to the desired location. Confirm proper placement by checking for negative pressure, injecting 3–5 mL of sterile saline into the tube, which will elicit a cough if placed in the airway, placing 5–10 mL of air into the tube and auscultating for borborygmus at the xyphoid, and by taking a radiograph. Once proper placement is established, secure the tube. Place the tube directly over the dorsal aspect of the nose and forehead and secure it with Chinese finger trap sutures or by suturing a tape tag directly to the skin. Finally, place an Elizabethan collar. Complications • • • • • Removal • Tubes can be removed at anytime or be left in place for up to 14 days • Cut sutures and then kink tube and gently, but briskly remove the tube to avoid fluid aspiration 11 Topical anesthetic (proparacaine hydrochloride 5%) Permanent marker 5% viscous lidocaine Sterile saline Needle holders Suture material, nonabsorbable • • • • • • Elizabethan collar Surgical site preparation materials ± Light sedation Stethoscope 3–5 mL syringe 5–10 Fr feeding tube Sphincter incompetence, esophagitis, or esophageal reflux when the tube passes through the cardiac sphincter Distal esophageal trauma due to large-bore tubes, reflux, or excessively heated foods Epistaxis, sinusitis Inadvertent tube removal by vomiting, sneezing, coughing, or pawing Diarrhea due to an all-liquid diet Tip: Continue to grasp the tube as close to the patient’s nares as possible to provide stability in case of patient sneezing. Tip: Using your thumb, push up on the nose into a pig position, then insert the tube ventrally and medially to the level of the mark on the tube. Tip: Patient discomfort (e.g., pawing, sneezing) can be lessened with the application of more topical anesthetic. 416 SECTION FOUR: PATIENT CARE SKILLS Skill Box 11.4 / Enteral Nutrition: Esophagostomy Tube Method Esophagostomy Tube Advantages • • • • • • • Disadvantages • General anesthesia Indications • Anorexic patients with a functional GIT • Patients with disorders of the oral cavity or pharynx (e.g., severe maxillofacial trauma, severe dental disease, neoplasia) Contraindications • • • • Patients Patients Patients Patients Setup • • • • • • Surgical site preparation materials Mouth speculum 8–20 Fr polyvinyl chloride feeding tube Permanent marker Eld feeding tube placement device Bandage material Procedure Administer general anesthesia and place the patient in right lateral recumbency. Aseptically prepare the lateral midcervical area from the ramus of the mandible to the thoracic inlet and dorsally and ventrally to midline. Place a mouth speculum and slightly extend the neck. Measure the tube from the point of exit (midcervical region) to the 7th or 8th intercostal space and mark with the permanent marker. Using the Eld feeding tube placement device, make an incision through the cervical musculature and place the tube into the esophagus according to manufacturer’s guidelines. The tube can also be placed by placing the carmalt down the esophagus to the point of insertion and incising over the tips. Place the tube into the tips of the carmalt and withdraw out the mouth. Then, using the carmalt, stylet, or fingers, push the tube down the esophagus until the proximal end of the tube flips rostrally when the tube is in place. Suture the tube to the cervical skin using the Chinese finger trap. An antibiotic ointment is used and a gauze bandage is placed. Radiograph to verify proper placement. Easy placement and removal Patient tolerance Slurried food can be used. Patient can eat and drink around the tube. Easy tube care for owner Tube removal can be performed anytime after placement. Large-bore tubes with with with who an esophageal dysfunction or stricture, esophagitis, megaesophagus, vomiting, regurgitation esophageal foreign body removal or esophageal surgery respiratory disease (e.g., severe cough, pneumonia) are hypothermic or hypotensive • • • • • No. 10 or No. 15 scalpel blade and handle, needle holders, Mayo scissors, Rochester carmal Suture material, nonabsorbable Sterile, water-soluble lubricant 3 mL syringe General anesthesia Complications • Inadvertent tube removal by vomiting, pawing, or chewing the end • Distal esophageal trauma due to large bore tubes, reflux, or excessively heated foods • Cellulitis Removal • Immediate or up to several months • To remove, cut the skin sutures and pull. • Exit site does not need further care; the holes will seal in 1–2 days and heal in 7–10 days. Tip: The tip of the feeding tube can be cut at the distal end just above the holes to allow a larger diameter for the food to exit to prevent clogging. Verify the cut end does not have sharp edges. CHAPTER 11 / PARENTERAL NUTRITION 417 11 Skill Box 11.5 / Enteral Nutrition: Gastrotomy Tube Without Gastropexy Method Gastrotomy Tube: Without Gastropexy Advantages • Direct visualization of the tube during placement • Placement of large diameter catheters • Can use calorie dense diets Disadvantages • Inability to perform gastropexy to ensure seal between stomach wall and body wall • Tube must remain in place for 10–14 days. Indications • Anorexic patients with functional GIT distal to stomach • Patients undergoing surgery of oral cavity, larynx, pharynx, or esophagus Contraindications • Patients with primary gastric disease: gastritis, gastric ulceration, or gastric neoplasia • Vomiting • Patients who are hypothermic or hypotensive Percutaneous Endoscopic Gastrotomy (PEG) Tube Placement Surgical Placement Setup • • • • • • • • • • • • • • • • Procedure Aseptically prep the left flank caudal to the left costal arch. The endoscope is placed in the stomach and the stomach is inflated. Digital palpation is performed and a small incision is made in the skin. An IV catheter is placed through the body wall into the stomach. The stylet is removed and suture is passed through, which is grabbed by the endoscope and extracted out of the mouth. The feeding tube is attached to the suture and then passed through the mouth into the stomach. The feeding tube is anchored at the skin surface where the incision had been made. The endoscope is reinserted to verify placement. The tube should be clamped and capped. Complications • • • • 11 418 14-gauge needle or catheter 20–24 Fr Pezzer’s catheter Endoscope General anesthesia Luer-Slip catheter plug Sterile lubricant Suture material No. 11 scalpel blade 18–20 Fr Foley catheter 6 mL syringe General surgical pack Large curved forceps Large-bore stiff stomach tube Mouth speculum Surgical site preparation material Suture material Administer general anesthesia. Aseptically prepare the skin of the left flank. Place a stomach tube or feeding tube placement device from the oral cavity to the stomach. Palpate the tube bulging against the left body wall. Direct it 1–2 cm caudal to last rib. Pass an 18-gauge needle through the abdominal wall and into the lumen of the stomach tube. Thread the needle with suture and direct through to oral cavity. Remove the stomach tube. Thread the end of the suture through the 18-gauge sovereign catheter and tie it to the proximal end of the Pezzer urinary catheter. Pull the suture and the attached catheter back into the stomach cavity, enlarge the exit hole, and pull sovereign catheter out until the mushroom tip of the Pezzer catheter is snugly against the body wall. This will ensure a seal between the stomach wall and body wall. Secure the catheter to the skin with sutures. Placement trauma (splenic laceration, pneumoperitoneum, and gastric hemorrhage) Vomiting, aspiration pneumonia, gastroesophageal reflux Peritonitis and dehiscence with tube migration Peristomal infection and cellulitis SECTION FOUR: PATIENT CARE SKILLS Skill Box 11.5 / Enteral Nutrition: Gastrotomy Tube Without Gastropexy (Continued) Removal • Can be removed after 14 days • Can be removed after 14 days • Feline: flatten mushroom tip with stylet and pull out with firm • Cut the sutures, deflate the cuff, and gently pull out the tube. traction. • Canine: either deflate the tip and extract or, for larger canines, cut the tube at the body wall and push the tip into the stomach to be passed in the animal’s feces. Skill Box 11.6 / Enteral Nutrition: Gastrotomy Tube With Gastropexy Method Gastrotomy Tube: With Gastropexy Advantages • • • • Disadvantages • General anesthesia • Feeding cannot take place until 24 hours after tube placement. Indications • Anorexic patients with functional GIT distal to stomach • Patients undergoing surgery of oral cavity, larynx, pharynx, or esophagus Contraindications • Patients with primary gastric disease: gastritis, gastric ulceration, or gastric neoplasia • Patients with disorders causing vomiting • Patients who are hypothermic or hypotensive Setup No special equipment Ease of finding the stomach in an anorexic patient Ensures immediate seal between stomach wall and body wall Confirmation of tube placement during procedure 11 Surgical Placement Laparotomy Placement • • • • • • • • • • • • • • • • Surgical site preparation material Large-bore stiff stomach tube Mouth speculum General surgical pack No. 11 scapel blade 18–20 Fr Foley catheter Suture material Large curved forceps 6 mL syringe Surgical site preparation material General surgical pack No. 11 scalpel blade 18–20 Fr Foley or Pezzer catheter Suture material Sterile saline 6 mL syringe CHAPTER 11 / PARENTERAL NUTRITION 419 Skill Box 11.6 / Enteral Nutrition: Gastrotomy Tube With Gastropexy (Continued) Administer general anesthesia. With a midline laparotomy approach, incise into the stomach. Place the Pezzer catheter directly into the stomach and place through the stomach and body wall as above. Fix the stomach wall to the body wall with sutures. Suture the abdomen closed. Procedure Administer general anesthesia. Aseptically prepare the skin of the left flank. Place a stomach tube into the stomach and palpate the left flank until the stomach tube can be felt and grasped. The tube should be felt 1–2 cm past the last rib and 3–4 cm ventral to the transverse processes of lumbar vertebrae 2, 3, and 4. While holding the tube, make a 2-cm incision over the end of the tube. Dissect down to the outside of the stomach lumen. Place a purse string suture in the stomach, and then with a scalpel blade, insert the tube. Inflate bulb on Foley catheter, withdraw stomach tube, and tighten purse string. Suture stomach wall to the body wall and place some subcutaneous sutures. Suture tube to abdominal skin. Complications • Leakage of gastric contents into the abdominal cavity resulting in peritonitis • Vomiting • Peristomal infection Removal • After 14 days or several weeks or months • Cut the sutures, deflate the cuff, and gently pull out the tube. • Exit site does not need further care; the holes will seal in 1–2 days and heal in 7–10 days. Skill Box 11.7 / Enteral Nutrition: Jejunostomy Tube 11 Method Jejunostomy Advantages • Immediate feeding of a highly digestible, low-bulk diet allowed • Intermittent bolus feeding can be used, but continuous feeding is typically better tolerated. Disadvantages • General anesthesia • Performing a celiotomy Indications • Patients undergoing oral, pharyngeal, esophageal, gastric, pancreatic, duodenal, or biliary tract surgery where the GIT is functional past the lesion or disease • Patients unable to protect their airway or at risk for pulmonary aspiration • Gastric, intestinal, or pancreatic disease Contraindications • Patients with lower GIT disorders or diseases • Patients who are hypothermic or hypotensive Setup • • • • • • 420 Surgical site preparation materials 5–8 Fr PVC feeding tube General surgical pack No. 11 scalpel blade Suture material Bandaging material SECTION FOUR: PATIENT CARE SKILLS Skill Box 11.7 / Enteral Nutrition: Jejunostomy Tube (Continued) Procedure Administer general anesthesia. Make a 2–3 mm stab incision through the abdominal wall. Through the celiotomy, select a section of jejunum that can be easily moved to the stab incision in the body wall. Incise into the jejunum; place the distal end of the feeding tube through the incision and pass 25–30 cm of the tube aborally into the jejunum. Suture the exit site of the jejunum and fix to the body wall. Secure the exit portion of the tube to the outside skin. Incorporate the tube into an abdominal bandage. Complications • Peritonitis and dehiscence with tube migration • Peritoneal or subcutaneous leakage Removal • Can be removed 10–14 days after placement Skill Box 11.8 / Enteral Nutrition Administration Method Tube Care Diet Calculations Administration Syringe • Rinse syringe with water after administration. • Calculate the resting energy requirement (see Skill Box 3.1, page 58). • Divide the total daily volume by 3–4 feedings. • Fill syringe with desired food and place the tip of the syringe in the cheek pouch directed toward the back of the mouth. • Gently depress plunger of syringe and deposit food. • Speed will depend on the rate of swallowing and patient tolerance. Orogastric Tube • Rinse tube with water after administration. • If diet is hyperosmolar (>350 mOsm/kg water) it will need to be diluted with water to make it hypoosmolar • Commercial diets not requiring blenderizing (e.g., CliniCare, Ensure, Jevity, Osmolite HN, Promote, Vital HN, Vivonex HN) Nasoesophageal/ Nasogastric Tube • Place a column of water in the tube and cap it at the end of each feeding to prevent intake of air, reflux of esophageal contents, and occlusion of the tube by the diet. Esophagostomy Tube • Place a column of water in the tube and cap it at the end of each feeding to prevent intake of air, reflux of contents, and occlusion of the tube by the diet. Gastrotomy Tube • Clean the site of tube exit with an antiseptic solution and monitor for movement daily. • Commercial diets typically requiring blenderizing (e.g., CNM-CV Feline, Iams NRF, Eukanuba Feline Max, Hill’s A/D, Hill’s P/D) • Once tube is in place (see Skill Box 12.1 Stomach Tube and gastric Lavage, page 428), attach food-filled syringe to the end of the tube. • Begin depressing plunger to administer required amount. • Calculate resting energy requirement (see Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58). • Give 50% volume on day 1, 100% volume on day 2, depending on patient tolerance. • Divide the total daily volume by 3–4 feedings. • Warm the food to body temperature in a warm water bath, stirring thoroughly to avoid hot spots. • Remove the cap on the tube and draw back on syringe to observe for any food or fluid. Food will only be seen if the tip of the tube is located within the stomach (e.g., nasogastric tube placement). • If more than 0.5 mL/lb are withdrawn, do not feed. • Infuse 5–10 mL water to ensure the tube is patent. • Infuse the allotted food slowly over a few minutes. • Infuse 5–10 mL water to clear tube and recap. CHAPTER 11 / PARENTERAL NUTRITION 421 11 Skill Box 11.8 / Enteral Nutrition Administration (Continued) Method Tube Care Diet Calculations Administration Jejunostomy Tube See above • Commercial liquid diets (e.g., Clinicare) • Liquid formulas are required to prevent tube clogging. • Dilution with water is not needed if a isosmolar formula is used. • Calculate the resting energy requirement (see Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58). • Dilute 1 : 1 on day 1, 1 : 0.5 on day 2, and full strength on day 3. • Give 25–50% volume on day 1 and gradually increase over the next 3–4 days. • May feed immediately after surgery. • Infuse continuously with an infusion pump, checking regularly for back pressure. • Do not hang bag for more than 24 hours as bacterial growth and contamination may occur. PARENTERAL NUTRITION 11 Parenteral feeding is nutrition delivered by the intravenous route, another form of assisted feeding that is typically reserved for the most critically ill patients—those with nonfunctioning GITs, unretractable vomiting, or those unable to withstand a surgical procedure for a jejunostomy tube. The natural enteral route of feeding should be the first choice of treatment or consequences such as mucosal atrophy and loss of the barrier function of the GIT are seen. However, parenteral feeding offers an alternative to those patients unable to obtain complete and proper nourishment through enteral feeding. Total parenteral nutrition (TPN) provides the total patient’s daily energy requirement, and partial parenteral nutrition (PPN) is used to supplement enteral feeding providing only a portion (40–70%) of the patient’s total daily energy requirement. Parenteral nutrition (PN) is administered ideally through a dedicated polyurethane or silicone central catheter or lumen of a central catheter. Long 422 SECTION FOUR: PATIENT CARE SKILLS peripheral catheters (jugular catheters placed peripherally) can be used but have an increased risk of phlebitis due to the high osmolality of the PN solution. With the use of peripheral catheters, the PN solution must be dramatically diluted, requiring larger volumes of fluid to be given, which may be contraindicated in some patients and comes with an increased risk of sepsis. The catheter must be dedicated for the sole purpose of administering the PN solution. Due to its high nutrient content, bacterial sepsis becomes a high risk. Along with a dedicate catheter, strict aseptic technique must be followed. Even though PN can see severe complications, these can be dramatically reduced with attention to aseptic technique in formulating solution, catheter placement, and catheter maintenance. The information in the tables below provides a brief outline of PN; please refer to a textbook dedicated to this topic for further information. Table 11.1 / Parenteral Nutrition Method Total Parenteral Nutrition Partial Parenteral Nutrition Advantages • Provides the total patient’s daily energy requirement • Provides an alternative to patient’s unable to obtain enteral support • Provides a portion of the patient’s daily energy requirement • Provides an alternative to patient’s unable to obtain sufficient enteral support Disadvantages • • • • • 24-hour nursing care required Difficulty inserting and maintaining a central venous catheter Difficulty obtaining or preparing PN solutions Complications (e.g., sepsis, thrombosis, refeeding syndrome, ↑ permeability of the GIT) Expense Indications • • • • • • • Nonfunctional GIT Postoperatively for some surgeries Prolonged ileus Severe malassimilation Patients with vomiting or regurgitation Pancreatitis Pulmonary aspiration risk Contraindications • Patients of marginal nutritional status • Well-nourished animals undergoing elective surgery or diagnostic procedures • Patients with fluid intolerance Setup • See Skill Box 8.9 Intravenous Catheter Placement: Peripheral and Jugular, page 349. • Areas of potential contamination should be kept to a minimum or avoided (e.g., stopcocks, tubing connections, piggybacking) Procedure • See Skill Box 8.9 Intravenous Catheter Placement: Peripheral and Jugular, page 349. Complications Metabolic • Refeeding syndrome is the rapid movement of ions from the plasma to the intracellular space (e.g., hypophosphatemia, hypokalemia, hypomagnesemia) seen with malnutrition, starvation, and prolonged diuresism possibly leading to muscle weakness, intravascular hemolysis, and cardiac and respiratory failure. • Hyper- or hypoglycemia, hyperlipidemia, hyperammonemia Mechanical • Sepsis of catheter or lines, thrombophlebitis Removal • Slow discontinuation essential to prevent a metabolic crises (e.g., hyper- or hypoglycemia) • • • • Patients of marginal nutritional status Patients who cannot receive a jugular catheter Patients needing supplemental feeding to enteral feeding Patients benefiting from nutritional support before surgery for gastrotomy or jejunostomy tube • Nondebilitated animals needing IV support for <7 days • Patients with vomiting or regurgitation • Debilitated patients needing full nutritional support • Well-nourished animals undergoing elective surgery or diagnostic procedures 11 • Discontinue PPN after patient consumes >50% of its energy requirement orally. • Slow discontinuation essential to prevent a metabolic crises (e.g., hyper- or hypoglycemia) CHAPTER 11 / PARENTERAL NUTRITION 423 Table 11.2 / Parenteral Nutrition Administration Patient and Catheter Care Diet Calculations Administration • Patient • Fluid, electrolyte, and acid-base abnormalities should be corrected before administration. • Check body weight and temperature twice daily. • Daily evaluation of serum electrolytes, glucose, total protein, serum lipids, PCV, BUN, and liver enzymes. • Catheter • Change sterile bandage daily, and observe for any signs of thrombosis, sepsis, or perivascular infusion. • Catheter should be placed in a new vein if there is any question to its patency, sterility, or tissue irritation around site. • If the catheter sepsis is suspected, obtain a blood sample for culture, remove catheter, and submit catheter tip for culture. • Change administration set every 24–48 hours. • Solutions contain a combination of a protein source, fat source, carbohydrate source, and possibly vitamins, electrolytes, and trace minerals (e.g., zinc, copper, manganese, chromium). • Commercial solutions can be purchased from human hospitals and health care suppliers; however, the contents of these solutions need to be compared to the specific requirements of the patient. • Homemade solutions consisting of amino acid solutions (e.g., 8.5% Travesol Injection with Electrolytes), lipid emulsions (e.g., Intralipid 20%), dextrose (e.g., 50% Dextrose), and vitamin supplements (e.g., vitamins B, A, D, E, K). • Homemade solutions must be made under strict aseptic technique using a laminar flow hood or PN compounding bags; therefore, purchasing already formulated mixtures is more practical for most hospitals. • Homemade TPN solutions should be mixed in an all-in-one container with separate sterile transfer lines for each solution. • Refer to a parenteral reference for the proper technique and calculation of each component. • Calculate the resting energy requirement based on ideal body weight (see Skill Box 3.1 Daily Caloric Requirement Worksheet, page 58). • Calculate protein, carbohydrate, and fat requirements based on ideal body weight. TPN • Administer 50% the first day and 100% the second day. PPN • Subtract the enteral calories from the RER; then administer the remaining. Calculation is critical and should be verified. • Unused PN solutions should be kept refrigerated; prepared solutions should be made fresh daily and not shared between patients. • Solutions being administered should not be at room temperature longer than 24 hours. • Place an inline 1.2-μm aireliminating filter in the administration set to avoid embolisms. • Infusion pumps should always be used to avoid bolus administration. • No fluid or drug can be added to the PN solution due to the risk of incompatibility and precipitates. • Using an aseptically prepared and dedicated catheter, slowly begin a 24 hour CRI of PN solution based on the patient’s RER. 11 424 SECTION FOUR: PATIENT CARE SKILLS Skill Box 11.9 / Worksheet for Calculating Total Parenteral Nutrition (TPN) b. Nonprotein calories 1. Resting energy requirement (RER) • The calories supplied by protein (4 kcal/g) are subtracted from the total calories needed to get total nonprotein calories needed. RER = 70 × (current body weight in kg) 0.75 or, for animals weighing between 2 and 30 kg: RER = (30 × current body weight in kg) + 70 = ____ kcal/day Tip: To calculate (BW kg)0.75 without a scientific calculator: multiply the weight by itself 3 times, then take the square root twice. 2. Protein requirements Standard Decreased (hepatic/renal failure) Increased (protein-losing conditions) Canine 4 g/100 kcal 2 g/100 kcal 6 g/100 kcal Feline 6 g/100 kcal 3 g/100 kcal 6 g/100 kcal (RER ÷ 100) × ____ g/100 kcal (protein req) = ____ g protein required/day 3. Volume of nutrient solutions a. 8.5% amino acid solution (0.085 g protein/mL) ____ g protein required/day ÷ 0.085 g/mL = ____ mL/day of amino acids ____ g protein required/day × 4 kcal/g = ____ kcal from protein ____ total kcal required/day − kcal from protein = ____ total nonprotein kcal needed/day c. Nonprotein calories are usually provided as a 50 : 50 mixture of lipid and dextrose. • This ratio may need to be adjusted if the animal is hyperglycemia or hypertriglyceridemia. 20% lipid solution (2 kcal/mL) To supply 50% of nonprotein calories ____ lipid kcal required ÷ 2 kcal/mL = ____ mL of lipid/day 50% dextrose solution (1.7 kcal/mL) To supply 50% of nonprotein calories ____ dextrose kcal required ÷ 1.7 kcal/mL = ____ mL of dextrose/day 4. Total daily requirements ____ mL ____ mL ____ mL ____ mL rate 8.5% amino acid solution 20% lipid solution 50% dextrose solution (use half on first day) total volume of TPN solution ÷ 24 hours = ____ mL/hr infusion 11 • Be sure to adjust the animal’s other intravenous fluids accordingly. • TPN vitamins and trace metals can be added during formulation if indicated. Tip: To calculate (BW kg)0.75 without a scientific calculator: multiply the weight by itself 3 times, then take the square root twice. Note: Reprinted with permission from Daniel Chan, DVM, DACVECC, DACVN, MRCVS. CHAPTER 11 / PARENTERAL NUTRITION 425 Skill Box 11.10 / Worksheet for Calculating Peripheral or Partial Parenteral Nutrition (PPN) 1. Resting energy requirement (RER) RER = 70 × (current body weight in kg) 0.75 or, for animals weighing between 2 and 30 kg: RER = (30 × current body weight in kg) + 70 = RER = ____ kcal/day Tip: To calculate (BW kg)0.75 without a scientific calculator: multiply the weight by itself 3 times, then take the square root twice 2. Partial energy requirement (PER) To supply 70% of the patient’s RER PER = RER × 0.70 = PER = ____ kcal/day 3. Nutrient requirements Patients 3–10 kg: PER × 0.25 = ____ kcal/day from dextrose PER × 0.25 = ____ kcal from amino acids PER × 0.50 = ____ kcal/day from lipids Patients 10–25 kg: PER × 0.33 = ____ kcal/day from dextrose PER × 0.33 = ____ kcal from amino acids PER × 0.33 = ____ kcal/day from lipids Patients >25 kg: PER × 0.50 = ____ kcal/day from dextrose Note: Reprinted with permission from Daniel Chan, DVM, DACVECC, DACVN, MRCVS. 11 426 SECTION FOUR: PATIENT CARE SKILLS PER × 0.25 = ____ kcal from amino acids PER × 0.25 = ____ kcal/day from lipids 4. Volume of nutrient solutions 5% dextrose (0.17 kcal/mL) ____ kcal/day from dextrose ÷ 0.17 kcal/mL = ____ mL/day 8.5% amino acids (0.34 kcal/mL) ____ kcal/day from amino acids ÷ 0.34 kcal/mL = ____ mL/day 20% lipid (2 kcal/mL) ____ kcal/day from lipid ÷ 2 kcal/mL = ____ mL/day 5. Total daily requirements ____ mL 5% dextrose ____ mL 8.5% amino acids ____ mL 20% lipid ____ mL total volume of PPN solution ÷ 24 hours = ____ mL/hr infusion rate • This calculation should approximate a patient’s maintenance fluid requirements. Be sure to adjust the animal’s other intravenous fluids according. The volume may be higher than maintenance fluid requirements for very small animals (<3 kg) or in animals with cardiac disease. • TPN vitamins and trace metals can be added during formulation if indicated. Chapter 12 Medical Procedures Gastrointestinal Procedures 428 Stomach Tube and Gastric Lavage 428 Gastrointestinal Tube Placement Verification 429 Abdominocentesis and Diagnostic Peritoneal Lavage 429 Enema, Warm Water 430 Ophthalmic Procedures 430 Schirmer Tear Test, Fluorescein Sodium Stain, and Tonometry 430 Key Words and Termsa Applanation Caustic Uroabdomen a Respiratory Procedures 431 Thoracocentesis and Thoracostomy Tube Placement 431 Nebulization, Coupage, and Metered-Dose Inhalers 432 Urogenital Procedures 434 Urine Collection 434 Urine Collection Devices 435 Urinary Catheterization 435 Urinary Catheter Maintenance 436 Abbreviations Additional Resources, page Fr, French GIT, gastrointestinal tract hr, hour IV, intravenous kg, kilogram MDI, metered-dose inhaler mL, milliliter mm Hg, millimeters of Mercury Anatomy, 3 Patient monitoring, 332 Recumbent patient care, 347 Suture techniques, 548 12 Key words and terms are defined in the glossary on page 631. 427 GASTROINTESTINAL PROCEDURES Skill Box 12.1 / Gastrointestinal Procedures: Stomach Tube and Gastric Lavage Method Stomach Tube Gastric Lavage Indications • Activated charcoal, barium, or food administration • Toxicity • Toxicity removal, and dilution Contraindications • Patients with disorders of the oral cavity, pharynx, larynx, or esophagus • Vomiting, ileus or gastric obstruction • Ingestion of corrosives, heavy metals, or petroleum distillates • Patients with disorders of the oral cavity, pharynx, larynx, or esophagus • Ingestion of caustic materials or petroleum distillates Setup • • • • • • • • • • • • Procedure Measure the feeding tube from the tip of the nose to the last rib and mark with a permanent marker. Prefill the tube with water to avoid introducing air. Lubricate the end of the tube and position the patient’s head in a slightly flexed position. Begin inserting the tube into the patient’s mouth, allowing the animal to swallow the tube. Continue to insert tube until the premeasured mark. Administer diet. Administer general anesthesia and place the animal in lateral recumbency. Measure the feeding tube from the tip of the nose to the last rib and mark with a permanent marker. Lubricate the end of the tube and position the patient’s head in a slightly flexed position. Insert the tube to the premarked line. Instill water at 5–10 mL/kg to obtain a slightly distended stomach while monitoring for respiratory distress. Then lower the tube below the patient’s head to remove the water by gravity. Turn patient and continue until all removed fluid is clear. Complications • Patient biting tube into pieces • Endotracheal placement: kittens do not have a gag reflex, allowing easy inadvertant endotracheal intubation and aspiration • Aspiration pneumonia • Vomiting • Aspiration pneumonia • Vomiting Removal • Kink tube and gently but briskly remove the tube to avoid fluid aspiration. • Kink tube and gently but briskly remove the tube to avoid fluid aspiration. 12 428 Stomach tube Lubricant Permanent marker Catheter-tipped syringes Activated charcoal, barium, or prepared food Towels SECTION FOUR: PATIENT CARE SKILLS Stomach tube Pump or 60 mL syringes Permanent marker Lubricant Mouth speculum 2 buckets (1 empty and 1 with body temperature water) Skill Box 12.2 / Gastrointestinal Tube Placement Verification • Attach a syringe and aspirate air—a negative pressure will result with esophagus or stomach tube placement, and aspirated air indicates tracheal placement. • Rapidly inject 6–12 mL of air into the tube while auscultating for borborygmus at the xyphoid. • Inject 3–5 mL of sterile saline; a cough will be elicited with tracheal tube placement. • Take a radiograph. Skill Box 12.3 / Gastrointestinal Procedures: Abdominocentesis and Diagnostic Peritoneal Lavage Method Abdominocentesis Diagnostic Peritoneal Lavage Indications • Acute abdominal pain, fever of unknown origin • Peritonitis, trauma, hemorrhage, uroabdomen, neoplasia, inflammatory conditions • Negative abdominocentesis • Acute abdominal pain, fever of unknown origin • Peritonitis, trauma, hemorrhage, neoplasia, inflammatory conditions Contraindications • Penetrating abdominal wounds • Penetrating abdominal injury Setup • Surgical site preparation materials • 20–22 gauge 1½ inch needle or 18–20 over-theneedle catheters • 3–6 mL syringes • Red and lavender top tubes • Culturettes • • • • • • • • Procedure Place the animal in lateral recumbency or in a standing position. Aseptically prepare a 10-cm square on the ventral abdomen with the umbilicus in the middle. Insert the needle 1–2 cm caudal to the umbilicus on the right side of the midline. Gently twist the needle on insertion to move aside any hollow organs. Needles in all 4 quadrants may need to be placed if fluid pocketing is suspected. Drip or aspirate fluid into the sterile tubes and culturette. Place the animal in lateral recumbency. Aseptically prepare a 10-cm square on the ventral abdomen with the umbilicus in the middle. Using the scalpel blade, cut ports into the side of the catheter. Insert the needle 1–2 cm caudal to the umbilicus on the right side of the midline. Gently twist the needle on insertion to move aside any hollow organs. Remove the stylet and observe for fluid. If noted, aspirate with the syringe; otherwise, instill 10–20 mL/kg warmed saline over 3–5 minutes. Remove the catheter and walk the patient while massaging the abdomen or gently roll the patient side to side. Return the patient to lateral recumbency and perform a 4-quadrant abdominocentesis to obtain 0.5–1 mL of fluid. • Stomach or internal organ laceration • Stomach or internal organ laceration Complications Surgical site preparation materials 20–22 gauge 1½ inch needle or 18–20 over-the-needle catheters #10 scalpel blade 3–6 mL syringes Sterile saline, warmed IV fluid administration set Red and lavender top tubes Culturettes Tip: A second needle may need to be placed 2 cm from the first to facilitate flow. Tip: Redirecting the needle, tapping or applying alternating dorsal and ventral hand pressure may help direct fluid toward the needle. CHAPTER 12 / MEDICAL PROCEDURES 429 12 Skill Box 12.4 / Gastrointestinal Procedures: Enema, Warm Water Method Enema, Warm Water Indications • Constipation • Elimination of toxic materials in the lower GIT Contraindications • Disorders of the lower GIT and rectum • Any human enema product Setup • Lubricant (e.g., K-Y Jelly) • Enema bucket and tubing Procedure • Animal is placed in lateral or sternal position. Sedation or anesthesia may be needed. The enema bucket is prepared by filling with warm water, mild soap, or a lubricant, and the tube is clamped off. The bucket is hung above the patient to facilitate flow. The tip of the tubing is lubricated and inserted into the rectum. The clamp is released and the tube is moved back and forth while moving cranially until 60–120 mL has been instilled. The tube is reclamped, and manual extraction is attempted by placing one hand with a deep abdominal grasp and the other hand along the spine to trap the feces. Using the spine hand, work the feces through the pelvic canal and extract with the index finger of the abdomen hand. Complications • Rectum or lower GIT trauma OPHTHALMIC PROCEDURES Skill Box 12.5 / Ophthalmic Procedures: Schirmer Tear Test, Fluorescein Sodium Stain, and Tonometry Method Schirmer Tear Test Fluorescein Sodium Stain Tonometry, Applanation Indications • Assessment of normal tear production • Discharge, inflammation, corneal disease (e.g., ulceration) • Epithelial defects (e.g., ulcerations, injury) • Evaluation of nasolacrimal system • Red or painful eye • Glaucoma Contraindications • Anesthetized eye • Use precollection of conjunctival or corneal epithelial cells • During intraocular surgery • Multiple lesions/ulcers Setup • Tear strips • Stain strips • Tonopen, TonoVet • ± Topical anesthetic 12 430 SECTION FOUR: PATIENT CARE SKILLS Skill Box 12.5 / Ophthalmic Procedures: Schirmer Tear Test, Fluorescein Sodium Stain, and Tonometry (Continued) Procedure Place the notched end of the tear strip in the palpebral fissure. The eyelids are held closed for exactly 1 minute. The strip is removed and measured and recorded according to the scale on the package. Normal: >15 mm Before removing the strip from the package, fold it in half lengthwise to form a trough. Remove the strip and place 2–3 drops of sterile saline or eye wash in the trough. Tilt the strip and allow the stain to drip into the patient’s eye. Do not touch the eye to avoid iatrogenic stain retention. Rinse the eye with eye wash onto a cotton ball. Examine the eye with a pen light followed by a Wood’s lamp observing for green stain indicating a break in the epithelium. To evaluate the nasolacrimal system, do not rinse and observe the nares in 5 minutes for canines and up to 10 minutes in felines for appearance of the green stain. The eye is anesthetized with a topical anesthetic (TonoVet does not require the topical anesthesia). The patient is loosely confined in a sitting or standing position with the head in a normal position perpendicular to the floor/table. The restrainer should be aware not to apply pressure on the jugular veins or thoracic inlet. The instrument is held in any orientation and the tip placed on the central cornea completely perpendicular to the corneal surface. The button is pushed and a reading is displayed. Several readings should be taken to assure consistent measurement. Normal: 15–25 mm Hg Complications • None noted • Iatrogenic stain retention • None noted RESPIRATORY PROCEDURES Skill Box 12.6 / Respiratory Procedures: Thoracocentesis and Thoracostomy Tube Placement Method Thoracocentesis Thoracostomy Tube Placement (closed chest) Indications • Pleural effusion (hemothorax, chylothorax, pyothorax, neoplastic effusion, right-sided cardiac failure) or pneumothorax • Multiple thoracocentesis required and/or failure to achieve negative pressure • Pleural effusion, pneumothorax Contraindications • Coagulopathies • Pleural adhesions • Coagulopathies • Pleural adhesions Setup • • • • • • Surgical site preparation materials 18–22 gauge needle or butterfly 3-way stopcock 20–60 mL syringe IV extension tubing Surgical blade • Local anesthetic agents • Collection basin • Red and lavender toped tubes • Culturettes • Oxygen 12 • Surgical site preparation materials • Thoracostomy tube or 12–20 Fr red rubber catheter • Syringe/chest drain valve • Christmas tree adapter • 3-way stopcock • • • • • • Minor surgical instrument pack Local anesthetic agents Suture materials Bandaging materials ± Suction Oxygen CHAPTER 12 / MEDICAL PROCEDURES 431 Skill Box 12.6 / Respiratory Procedures: Thoracocentesis and Thoracostomy Tube Placement (Continued) Procedure Place the patient in sternal or lateral recumbency. Surgically prep a 4–8 cm square in the center of the right side of the chest at the 7th–9th intercostal space. Place a local block in the awake patient. Insert the needle in the intercostal space avoiding the intercostal arteries on the caudal aspect of each rib. Advance the needle into the pleural space while angling the needle flat against the chest wall with bevel outwards. While moving the needle along the chest wall, position the needle dorsally to obtain air and ventrally to obtain fluid. Aspirate and reserve fluid in sterile tubes via the 3-way stopcock. Place the patient in lateral recumbency or a position resulting in the least amount of stress. Surgically prepare the entire lateral thorax. Have an assistant pull the skin from the 9th–10th intercostals space cranially until it lies over the 7th–8th intercostals space. Place a local block being sure to include the nearby pleura and intercostal muscles. Making a skin incision over the 9th–10th intercostal space, insert the thoracostomy tube with stylet or use surgical instruments to dissect down to the pleural space. The tube is then directed to the cranioventral thorax. The skin is then released allowing a subcutaneous tunnel to the 7th–8th intercostal space to be made. The tube is sutured in place using subcutaneous and finger -trap sutures. A chest wrap is placed to further secure the tube and prevent contamination. The tube is connected to the Christmas tree adapter, IV extension set, and syringe and evacuation is begun. Complications • Trauma or laceration to the lungs and intercostal vessels • Trauma or laceration to the lungs and intercostal vessels • Worsening pneumothorax Maintenance • N/A • All contact should be performed aseptically. • Frequent or continuous suction • Tube bandage should be changed daily. Removal • Remove needle, and observe site for fluid leakage. • Suction the chest while removing clamp; place a gauze over insert point, then suture or glue together skin edges. Tip: Place a mark on the tubing to indicate where the bevel of the needle is to allow correct positioning while in the thorax. Tip: After the needle has been inserted through the skin, fill the hub of the needle with sterile saline, as the needle is advanced the saline will be pulled in as the pleural space is entered. Skill Box 12.7 / Respiratory Procedures: Nebulization, Coupage, and Metered Dose Inhalers 12 Nebulization is an aerosol therapy providing a fine mist of liquid droplets in a carrier gas. Nebulization is indicated to moisten respiratory tissue, loosen secretions, and stimulate coughing. Ideally, the patient uses slow, deep breaths to allow the peripheral airways to be reached; otherwise, treatment will be concentrated in the upper airways. Improvement with subsequent treatments will allow better treatment of lower respiratory system. Treatments are often followed by coupage as a way of breaking up and eliminating respiratory debris through coughing. Metered-dose inhalers are able to deliver high drug concentrations to the lungs while avoiding or minimizing systemic side effects. Method Nebulization Coupage Metered-Dose Inhalers (MDIs) Indications • Upper respiratory conditions (e.g., asthma, pneumonia, infectious tracheobronchitis) • Tracheostomy tube care • Administration of medications (e.g., gentocin, aminoglycosides) • Upper respiratory conditions (e.g., asthma, pneumonia, infectious tracheobronchitis) • Following nebulization • Upper respiratory conditions (e.g., asthma, pneumonia, chronic bronchitis) • Administration of medications (e.g., Gentocin, aminoglycosides) 432 SECTION FOUR: PATIENT CARE SKILLS Skill Box 12.7 / Respiratory Procedures: Nebulization, Coupage, and Metered Dose Inhalers (Continued) Contraindications • Further damage or trauma from coughing • Thoracic trauma, thrombocytopenia • Further damage or trauma from coughing • Adverse reactions to medicine Setup • Nebulizer machine • Medical cups • Extension adapters • N/A • Inhaler with spacer • Facemask • Medication (e.g., glucocorticoids, albuterol, salmeterol, nedocromil) Procedure The nebulizer housing is filled with sterile saline (± medications) and prepared according to manufacturer’s instructions. The housing is placed in front of the patient’s mouth and nose, and the animal is allowed to breathe normally. Treatments are typically 10–20 minutes. Using a cupped hand on one or both sides, repeated thumps are made against the chest wall. Work from back to front and lower to upper areas of the chest. Treatments are typically 4 times a day following nebulization. The MDI is primed and the inhaler shaken. Place the inhaler over the patient’s face and press the metal canister down firmly and fully. Hold the mask in place for 5–10 seconds or 5 breaths. Wait 30–60 seconds and repeat as needed according to the medication directions. Complications • Concentration of treatment in upper airway • Thoracic trauma • Patient resistance • • • • Extension hoses Elbow adapter 0.9% saline Medication 12 CHAPTER 12 / MEDICAL PROCEDURES 433 UROGENITAL PROCEDURES Skill Box 12.8 / Urine Collection: Voided, Manual Expression, and Cystocentesis Method Voided Manual Expression Cystocentesis Indications • Urine collection • Urine collection • Neurologic impairment • Urinalysis • Bacterial culture Contraindications • Bacterial culture • Urethral obstruction • Bacterial culture • Urethral obstruction Setup • Collection cup or litter box • Clean syringe • Collection cup • • • • Procedure Canine: walk on a short leash and catch a voided midstream sample. Feline: place in a cage with a clean, empty litter box. Place the patient in lateral recumbency and clean the vulva or prepuce. Palpate the caudal abdomen for a bladder. Isolate and trap the bladder between the spine and hand and apply steady, firm pressure until a stream of urine is produced. Have the animal in a standing position or place the animal in lateral or dorsal recumbency. Palpate the bladder and isolate against the spine. Insert the needle into the bladder in a caudal-dorsal direction at a 45º angle toward the midline. (Male canines: caudal to the umbilicus and to the side of the sheath. Female canines and felines: ventral midline caudal to the umbilicus.) Aspirate the syringe slowly. When finished, stop aspirating and slowly and smoothly remove the needle. Complications • Altered results from trace amounts of soaps, disinfectants, bacteria, or any other debris • Bladder injury or rupture • Introduction of RBCs and protein into the urine sample • • • • 22–23 gauge needle 6–12 mL syringe Alcohol Sterile red topped tube Puncture of internal organs Bladder hematoma Urine leakage Shock (rare, but a potential vagal response) Tip: To help locate the bladder, pour alcohol onto the abdomen of an animal in dorsal recumbency and it will pool in the location of the bladder, or mentally draw an X crossing over the abdomen between the last 2 sets of mammary glands. These techniques are then confirmed by palpation. Tip: Always save ≥1 mL of sterile urine for an unexpected culture. 12 434 SECTION FOUR: PATIENT CARE SKILLS Skill Box 12.9 / Urine Collection Devices Litter Pan • A clean litter pan or a disposable aluminum cooking pan can be used with one of the following techniques: • • • • Empty Covered within a plastic bag Nonabsorbent pellets Shredded wax paper Collection Cups alter the urine results, leading to a misdiagnosis. Using the most appropriate collection cup is required for proper results. Collection cups can be fixed to a long metal pole (e.g., aluminum rod or coat hanger) to allow access to the urine stream without disturbing the patient. • Sterile red top tube • Sterile urine cup • Cleaned container lined with a plastic bag • Use of an improper collection cup can give misleading information on the urinalysis. Many detergents and container content residue can Skill Box 12.10 / Urogenital Procedures: Urinary Catheterization Method Urinary Catheterization Indications • Urine collection and/or quantification • Nonambulatory patient care Contraindications • Urethral trauma or injury Setup • Surgical site preparation materials • Lubricant (e.g., K-Y Jelly) • Urinary catheter (e.g., red rubber, Foley, infant feeding tube) • • • • Procedure Canine, Female Place the patient in a standing position or in ventral recumbency and clip and clean the external urethral opening. Apply 2 stay sutures if the catheter is to remain in place. Using aseptic technique, apply lubricant to the catheter tip. Flush the vagina with saline or sterilized water injected through a syringe. Place a speculum in the vagina to visualize the urethral opening. The urethral orifice is 3–5 cm cranial to the ventral commissure of the vulva, just cranial to the clitoral fossa. Place the catheter past the clitoral fossa and advance along the ventral floor of the vagina until it enters the urethral fossa. Urine will begin to flow once the catheter has reached the bladder. Connect the catheter to the closed collection system and suture into place with a Chinese finger trap suture pattern. If using a Foley catheter, fill the balloon with the correct amount of sterile water. Canine, Male Place the animal in lateral recumbency and shave the fur on the tip of the prepuce. Clean the tip of the prepuce and then place 2 stay sutures on either side (if the catheter is to remain). Expose the urethral opening by reflecting the prepuce away from the penis. Clean the tip of the penis while avoiding any contact with the prepuce or surrounding hair. Wearing sterile gloves, measure the catheter from the tip of the penis to the bladder. Lubricate the end of the catheter and insert the catheter into the urethral opening. Apply gentle pressure to advance the catheter past the level of the os penis and the point where the urethra curves around the ischial arch. Urine will begin to flow once the catheter has reached the bladder. Connect the catheter to the closed collection system and suture into place with a Chinese finger trap suture pattern. If using a Foley catheter, fill the balloon with the correct amount of sterile water. • Urethral obstruction • Neurologic impairment Vaginal speculum Minor surgical pack Suture material Urine closed collection system CHAPTER 12 / MEDICAL PROCEDURES 435 12 Skill Box 12.10 / Urogenital Procedures: Urinary Catheterization (Continued) Method Urinary Catheterization Feline, Female Sedate or anesthetize the patient and place in lateral or sternal recumbency. Clean the vulva and place 2 stay sutures (if catheter is to remain in place). Wearing sterile gloves, measure the catheter from the vulva to the bladder. Advance the catheter into the urethral opening while applying gentle downward pressure on the catheter tip. Gently advance and retract the catheter until entry into the urethra. Urine will begin to flow once the catheter has reached the bladder. Connect the catheter to the closed collection system and suture into place with a Chinese finger trap suture pattern if catheter is to remain in place. Tape catheter to tail while assuring enough catheter for normal movement. Complications • Urethral inflammation or injury • Introduction of bacteria into the bladder • Introduction of RBCs, protein, and transitional epithelial cells Maintenance • See Skill Box 12.11 Urinary Catheter Maintenance, page 436. Removal • Remove sutures and gently and swiftly remove the catheter. Feline, Male Sedate or anesthetize the patient and place in lateral or dorsal recumbency. Clean the prepuce and place 2 stay sutures (if the catheter is to remain in place). Wearing sterile gloves, measure the catheter from the penis to the bladder. Expose the urethral opening by reflecting the prepuce away from the penis and holding tightly at the base of the penis. Clean the penis and avoid any contact with the prepuce or surrounding hair. Lubricate the tip of the catheter, insert into the urethral opening, and gently advance the catheter in a rotary motion. While advancing the catheter, gently pull the penis and prepuce out to straighten the urethra. Urine will begin to flow once the catheter has reached the bladder. Connect the catheter to the closed collection system and suture into place with a Chinese finger trap suture pattern if catheter is to remain in place. Tape catheter to tail while ensuring enough catheter for normal movement. Tip: Closed collection system consists of sterile IV tubing and fluid bag connected via a Christmas tree adaptor to the urinary catheter. Tip: Urinary catheters can be placed in the freezer to make them more rigid and to allow easier placement. 12 Skill Box 12.11 / Urinary Catheter Maintenance Patient • Voided urine and dehydration should be monitored to ensure normal micturition (normal: 1–2 mL/kg/hr). • The vulva or prepuce should be cleaned twice daily with an antimicrobial solution and gently dried. Catheter • Gloves should always be worn when working with the catheter and closed collection system. • Catheter patency should be evaluated every 4 hours. 436 SECTION FOUR: PATIENT CARE SKILLS • Observation of urine flow • Instill 1–2 mL of saline into the catheter and then aspirate. Closed Collection System • Place below the patient to prevent backflow of urine to the patient. • Place on a clean surface (off the floor) to prevent bacterial contamination (e.g., clean towel). • All collection system connections should form a tight seal and be cleaned with a disinfectant if disconnected. Section Five Anesthesia and Anesthetic Procedures Chapter 13: Anesthesia 439 Chapter 14: Dentistry 497 Chapter 15: Surgery 521 Chapter 13 Anesthesia Guidelines for Safe Anesthesia 441 Preanesthetic 442 Preanesthetic Evaluation 442 Case-Based Anesthesia 444 Preanesthetic Drugs 451 Anesthesia 451 Anesthetic Administration 451 Anesthetic Machine 451 Machine Setup 451 Anesthetic Breathing Systems 452 Anesthetic Administration 453 General Anesthesia Induction 453 Endotracheal Intubation 454 Figure 13.1 Endotracheal Intubation 455 Endotracheal Complications 456 Perioperative 456 Patient Care 456 Intermittent Positive-Pressure Ventilation (IPPV) Anesthetic Monitoring 458 Stages of Anesthesia 458 Anesthesia Monitoring 460 458 Postanesthesia 466 Recovery 466 Postanesthetic Monitoring 467 Local and Regional Anesthesia 470 Ventilation 474 General Information 474 Administration 475 Anesthetic Drugs 477 Preanesthetic Drugs 477 Anticholinergic Drugs 477 Atropine and Glycopyrrolate 478 Phenothiazines 478 Acepromazine Maleate 479 Benzodiazepines 480 Diazepam and Midazolam 480 α2-Agonists 481 Xylazine and Medetomidine 482 Opioids 484 Butorphanol and Buprenorphine 485 Fentanyl and Hydromorphone 486 Morphine Sulfate and Oxymorphone HCl 13 487 439 Injectable Induction Anesthetics 488 Barbituates 488 Thiobarbituates and Methylated Barbituates Cyclohexamines 490 Ketamine and Tiletamine 491 Propofol 492 Propofol (continued) 492 13 440 SECTION FIVE: ANESTHESIA AND ANESTHETIC PROCEDURES 489 Etomidate 493 Etomidate (continued) 494 Inhalant Anesthetics 494 Halothane and Isoflurane 495 Sevoflurane 496 Key Words and Termsa Acidotic Apneustic breathing Ataxia Azotemia Barotrauma Cataleptic Catecholamine Cholestasis CO2 absorber Compressed gas Cylinders Cyanosis Dysphoria Ectopic Emetics Endotoxemia Exsanguinate Flowmeter Hypercapnia Hypercarbia Hyperkinesis Hypocapnia Hypocortisolemia Hypotonia Iatrogenic Intercostal a Interpleural Manometer Metabolic acidosis Miosis Moribund Myoclonus Nonrebreathing system Nystagmus Oliguria Oncotic Paradoxical Perivascular Pop-off valve Rebreathing bag Rebreathing system Receptor Reservoir bag Scavenger hose Stridor Synechiae Thyroid storm Tidal volume Vasovagal Vomition Wind-up Abbreviations Additional Resources, page APTT, activated partial thromboplastin time ASA, American Association of Anesthesiologists BG, blood glucose BP, blood pressure bpm, beats per minutes CNS, central nervous system CRI, constant rate infusions CSF, cerebrospinal fluid CV, cardiovascular ECG, electrocardiogram ET, endotracheal GABA, γ-aminobutyric acid IM, intramuscular IPPV, intermittent positive-pressure ventilation IV, intravenous K+, potassium kg, kilogram lb, pound mg, milligram MM, mucous membranes NMDA, N-methyl-D-aspartic acid PCV, packed cell volume PT, prothrombin time SQ, subcutaneous TP, total protein VPC, ventricular premature contraction/complex Anatomy, 3 Blood chemistries, 74 Blood gases, 335 Blood pressure, 332 Cardiac examination, 30 Catheter placement, 349 CAVM, 557 Coagulation tests, 115 Complete blood count, 104 Constant rate infusion, 392 Drug administration, 348 Electrocardiography, 338 Fluid therapy, 359 Heat administration, 346 Laboratory, 71 Oxygen therapy, 375 Pain management, 379 Physical examination, 18 Pulmonary examination, 32 Radiology, 157 Surgery, 521 Thoracocentesis, 431 Thoracostomy tube, 431 Ultrasound, 197 Urinalysis, 147 Vital signs, 19 Key words and terms are defined in the glossary on page 631. GUIDELINES FOR SAFE ANESTHESIA Anesthesia is the powerful ability to provide restraint, loss of consciousness, elimination of pain, and seizure control to our patients. To provide this act safely and effectively, the anesthetist must have a complete understanding of many factors. The patient’s history and current condition must be evaluated, and the anesthetist must have thorough knowledge of the anesthetic equipment, anesthetic drugs, monitoring techniques, recovery protocol, and emergency procedures. It is only through this knowledge that the inherent risks of anesthesia can be lessened and anticipated. • Hypoventilation • ↓ Tear production Patient Evaluation • Signalment 13 • History • Weight • Vital signs • Physical examination Potential Problems Associated With All Anesthetic Procedures • Laboratory workup • Hypothermia • Diagnostic tests • Hypotension • ASA physical status CHAPTER 13 / ANESTHESIA 441 Patient Preparation Induction • Venous access • Providing a calm, relaxed, and pain-free state • Providing a rapid loss of consciousness without excitation, distress, or struggling potentially resulting in injury • Optimizing effective circulating blood volume • Obtaining control of the airway Perioperative Machine Preparation • Maintaining normal surgical vital signs • Leak test • Maintaining a surgical plane of anesthesia • Setup Recovery Drug Protocol • Emergency drug reference sheet prepared • Choose a anesthetic drug protocol that does not further complicate existing conditions or initiate others • Allowing a smooth recovery without excitation, distress, or struggling • Maintaining normal vital signs • Analgesia plan PREANESTHETIC Table 13.1 / Preanesthetic Evaluation A complete review of this list should be conducted on each patient prior to the administration of any drugs. These initial assessments will prove valuable in choosing the correct drug protocol and in monitoring the patient during and after the anesthetic procedure. Category 13 Parameters to Evaluate Signalment The species, breed, age, and temperament of the patient can have direct implications on the type of drugs used during the anesthetic procedure along with the type of monitoring used. History Both recent and past history of anesthetic episodes, medications, meals, and ongoing diseases will affect the anesthetic protocol. Weight • A current weight in both kilograms (kg) and pounds (lb) Vital Signs • See Table 2.1 Preliminary Examination, page 18. • • • • • • Physical Examination • See Chapter 2 Physical Examination, page 20. A complete physical exam must be performed to help acquire a baseline for the patient. This initial exam must be performed prior to the administration of any drugs for accurate results. 442 Temperature Pulse Heart rate Respiration rate Capillary refill time Mucous membrane (MM) color SECTION FIVE: ANESTHESIA AND ANESTHETIC PROCEDURES Table 13.1 / Preanesthetic Evaluation (Continued) Category Laboratory Workup • See Chapter 4, Laboratory, page 201. Parameters to Evaluate A wide range of protocols exist for preanesthetic laboratory workup. However, all patients should have a PCV/TP performed with a CBC and serum chemistry panel depending on the patient’s presenting condition, history, and results of the PCV/TP. Additional tests may also be necessary. • • • • • • PCV/TP Serum chemistry panel CBC Electrolytes Urinalysis Coagulation profile • Activated clotting time • PT/APTT assays • Platelet count • Venous or arterial blood gases Additional Diagnostic Testing Radiography is used to detect and evaluate congenital or acquired cardiopulmonary disease or conditions associated with traumatic injuries; e.g., pulmonary contusions, diaphragmatic hernia, or pneumothorax. Abdominal radiographs can detect and evaluate congenital or acquired organ disease; e.g., hepatic, urinary, or gastrointestinal diseases. Electrocardiography should be performed in patients with suspected or known heart disease, those with recent trauma and possible myocarditis, and patients with electrolyte abnormalities. Ultrasound can be an additional tool used to evaluate the degree of many diseases or traumatic states. ASA Physical Statusa The American Society of Anesthesiologists’ (ASA) Physical Status Classification System adapts to small animal medicine with ease. It allows a system to evaluate the patient based on the presence and severity of systemic disease present. I II III IV V a Excellent anesthetic risk; patients with no underlying disease, undergoing elective surgeries Good anesthetic risk; mild to moderate disease changes or signs of extreme fear and anxiety Fair anesthetic risk; severe disease changes that limits activity, but is not incapacitating Poor anesthetic risk; severe disease changes that limits activity and are a constant threat to life Critical anesthetic risk; moribund, not expected to survive with or without surgery Based on ASA Physical Status Classification System of the American Society of Anesthesiologists. A copy of the full text can be obtained from ASA, 520 N. Northwest Highway, Park Ridge, IL 60068-2573. 13 CHAPTER 13 / ANESTHESIA 443 Table 13.2 / Case-Based Anesthesia Along with the basic preanesthetic evaluation, a patient presenting with a existing health concern should be further evaluated and have a specific anesthetic plan designed for them. Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery • Maintain the endotracheal tube as long as possible in recovery. • Possibly sedate to reduce stress during recovery and allow tube to remain in longer. • Possibly continue oxygen administration until extubation. • Closely monitor respiration for at least an 1 hour following recovery. • Extend neck and tongue to facilitate breathing. Brachycephalic • English Bulldog, French Bulldog, Pug, Boston Terrier, Boxer, Shar pei, and Pekingese • Evaluate degree of respiratory compromise. • Baseline oxygen saturation (SpO2) reading on room air • Thoracic radiographs ↑ Vagal tone Airway obstruction Bradycardia Cyanosis Difficulty or failure to intubate (e.g., laryngeal collapse, small tracheal lumen size, and difficult visualization) • Dyspnea and apnea Preanesthetic • Butorphanol and atropine or glycopyrrolate • Meperidine and atropine or glycopyrrolate Induction • Ketamine and diazepam • Propofol and diazepam • Thiopental and diazepam • Avoid deep sedation. • Preoxygenate for 5–10 minutes. • Rapid IV induction with subsequent intubation • Prepare for a tube size smaller than anticipated. • Prepare for possible tracheostomy tube placement. • • • • • No special considerations • Preoxygenate. • Observe for overhydration. • Pediatric protocol for induction • Avoid anticholinergics, barbituates, α2-agonists, and halothane. • No special considerations once stabilized • Preoxygenate. • Avoid α2-agonists and halothane • Propofol may further hypotension • IPPV may contribute to further hypotension; may need to ↑ fluid therapy. • • • • • Congenital Heart Disease • Obtain resting heart rate and respiratory rate. • Thoracic radiographs Bradycardia Ventricular ectopic beats Hypothermia Pulmonary edema Hypotension/Hypovolemia • Blood pressure • Cardiac arrest • Circulatory failure • Hemodilution (with IV crystalloids) 13 444 SECTION FIVE: ANESTHESIA AND ANESTHETIC PROCEDURES • Stabilize with fluids and/or whole blood prior to anesthetic procedure. • Observe for overhydration/ hemodilution; use low-volume IV fluid rate. • Intermittent PCV and TP monitoring Table 13.2 / Case-Based Anesthesia (Continued) Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery • • • • • Arrhythmias Bradycardia Hypovolemia Pulmonary edema Tachycardia Preanesthetic • Oxymorphone (and ± glycopyrrolate • Butorphanol (and ± glycopyrrolate Induction • Etomidate and diazepam • Thiopental and diazepam • Propofol and diazepam • Innovar-Vet • Preoxygenate. • Avoid drugs producing tachycardia (anticholinergics and cyclohexamines), except with congestive cardiomyopathy, where ↑ heart rate may be beneficial. • Avoid α2-agonists and halothane. • Observe for overhydration. • Continuous ECG and BP monitoring • • • • • Anesthetic drug overdose Delayed recovery Fluid overload Hypoxemia Pulmonary edema • No special considerations • Preoxygenate. • Highly protein bound drugs will give an ↑ effect and the dose should be ↓. • Avoid α2-agonists and halothane. • Anesthesia causes a 3–5% ↓ in PCV • Blood transfusion if PCV is <25–30% • Intermittent monitoring of PCV and TP should be done intraoperative and postoperative • Conservative fluid therapy to avoid pulmonary edema due to reduced vascular oncotic pressure (esp. crystalloids) • Supplemental oxygen postoperative • No special considerations • No special considerations • No special considerations Impaired Cardiac Function • +/− Cardiac ultrasound • Blood pressure • ECG • PCV/TP • Serum potassium • Thoracic radiographs • Urinalysis Anemia/Hypoproteinemia • Complete blood evaluation • Urinalysis Heartworm Disease • Complete blood evaluation • Thoracic radiographs • ↓ Cardiac output • Cardiac arrhythmias • Pulmonary dysfunction 13 CHAPTER 13 / ANESTHESIA 445 Table 13.2 / Case-Based Anesthesia (Continued) Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery ↑ Cardiac output Dyspnea Hypertension Hypotension Neonatal depression from anesthetic agents • Tachycardia • Uterine hemorrhage • Vomiting Preanesthetic • Oxymorphone and atropine • Butorphanol and atropine Induction • Propofol • Thiopental • Ketamine and diazepam • Etomidate and diazepam • ↓ Drug dose by 40% and inhalant dose by 25%. • Preoxygenate. • Consider drugs that can be antagonized or are rapidly metabolized. • Avoid pentobarbital because of its close to 100% mortality in neonates. • Avoid phenothiazines, benzodiazepines, cyclohexamines, and α2-agonists. • Morphine epidural will ↓ inhalant dose and allow smoother recovery. • IPPV to compensate for the distended abdomen. • Surgical preparation should be done in an awake animal in left lateral recumbency to remove pressure from the vena cava. • See Skill Box 7.4 Neonatal Resuscitation Post Cesarean, page 317. • • • • Preanesthetic • Butorphanol and atropine (or glycopyrrolate) • Meperidine and atropine (or glycopyrrolate) • Oxymorphone and atropine (or glycopyrrolate) Induction • Thiopental and diazepam • Propofol and diazepam • Consider drugs that can be antagonized or are rapidly metabolized. • Avoid α2-agonists and cyclohexamines as sole agents with high doses. • Patient should be stabilized and regulated if possible. • Procedure should be scheduled in early morning after normal administration of insulin. • Possibly ↓ insulin dose by 50% on day of surgery due to fasting. • Intermittent BG monitoring, maintaining at 150–250 mg/dL. • IV fluid administration of 5% dextrose if needed • Maintain IV fluids to counteract diuresis caused by hyperglycemia. Cesarean, Emergency • PCV and TP • Serum calcium • Thorough history • • • • • Endocrine • Diabetes mellitus • Blood glucose • Urinalysis Delayed recovery Hyperglycemia Hypoglycemia Higher infection risk 13 446 SECTION FIVE: ANESTHESIA AND ANESTHETIC PROCEDURES Table 13.2 / Case-Based Anesthesia (Continued) Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery • • • • • • Airway obstruction Bradycardia Hypoglycemia Hyper- or hypotension Hypoxemia “Thyroid storm” (tachycardia, hypertension, cardiac arrhythmias, hyperthermia, and shock) Preanesthetic • Oxymorphone Induction • Propofol • Etomidate and diazepam • Thiobarbiturate and diazepam • Avoid α2-agonists and cyclohexamines. • Avoid phenothiazines and barbituates with complicated disease. • ↑ Oxygen consumption. • Due to the thyroid tumor, intubation may be more difficult, leading to airway obstruction. • Attempt to regulate T4 level before anesthesia • β-Blockers for severe tachycardia may be necessary. • Continuous ECG and blood pressure monitoring • Intermittent BG monitoring • • • • Arrhythmias Hypocortisolemia Hypotension Shock • No special considerations • Avoid phenothiazines and etomidate. • Patient should be stabilized and regulated before an anesthetic procedure. • IV fluid and glucocorticoids administration preoperative, intraoperative, and postoperative to avoid an addisonian crisis • • • • • • Bradycardia Delayed recovery Hypotension Hypothermia Respiratory difficulty Hypoventilation Preanesthetic • Meperidine and atropine • Butorphanol and atropine • Oxymorphone and atropine Induction • Ketamine and diazepam • Etomidate and diazepam • Propofol and diazepam • Thiopental and diazepam • Consider drugs that can be antagonized or are rapidly metabolized. • Avoid phenothiazines, α2agonists and morphine. • Heat support • Monitor breathing during surgery (e.g., respirometry, capnography, or reservoir bag). Hyperthyroidism • +/− Cardiac ultrasound • Complete blood evaluation • ECG • T4 level • Thoracic radiographs Hypoadrenocorticism • Electrolytes Hypothyroidism • PCV and TP 13 Gastrointestinal • Gastric dilatation volvulus • Arterial gases • Complete blood evaluation • ECG • Hypovolemic status • • • • • Cardiac arrhythmias Septic shock Metabolic acidosis Hypokalemia Peritonitis Preanesthetic • Oxymorphone and glycopyrrolate Induction • Ketamine and diazepam • Oxymorphone and diazepam • Innovar-Vet • Stabilize shock before anesthesia • Preoxygenate • Avoid the use of emetics (e.g., morphine, acepromazine, and xylazine). • Avoid nitrous oxide. • IPPV throughout surgery • Intermittent PCV and TP monitoring • Continuous ECG and BP monitoring intraoperative and postoperative • IV antibiotics CHAPTER 13 / ANESTHESIA 447 Table 13.2 / Case-Based Anesthesia (Continued) Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery • Hypotension Preanesthetics • Opioids • Avoid the use of α2-agonists and halothane. • Monitor and care for the underlying condition. • • • • • • • • No special considerations • Dose drugs on lean weight to prevent overdosing. • Preoxygenate. • IPPV throughout surgery • Drugs that distribute to the body fat will have longer recovery times (halothane). • Avoid dorsal recumbency with head positioned down if possible. • Monitor breathing during surgery (e.g., respirometry, capnography or reservoir bag). • Maintain endotracheal tube as long as possible. Pancreatitis • Complete blood evaluation Obesity • Complete blood evaluation • Estimate lean body weight. Airway obstruction Delayed recovery Drug overdose Hyperthermia Hypoventilation Hypoxemia Respiratory difficulty Geriatric • A patient who has reached 75% of its expected life span • Complete blood evaluation • ECG • Thoracic radiographs • Thorough history and medications • Thyroid hormone levels • Urinalysis • • • • ↓ Organ function Hypotension Hypothermia Hypoventilation Preanesthetic • Meperidine and atropine • Butorphanol and glycopyrrolate Induction • Thiopental and diazepam • Ketamine and diazepam • ↓ Drug dose by 30–50%. • Avoid phenothiazines and α2-agonists. • Allow longer time for response to drugs. • Preoxygenate. • Monitor anesthetic level for inhalant overdose. • Heat support • Monitor fluid rate to ensure adequate hydration and urine production (e.g., enlarging bladder, skin tenting, MM). • • • • • • • • Delayed recovery Further hepatic disease Hypogylcemia Hypokalemia Hypotension Hypothermia Pulmonary edema Seizures Preanesthetic • Meperidine and atropine • Butorphanol and atropine • Oxymorphone and atropine Induction • Propofol • Thiopental • Isoflurane • Avoid phenothiazines and α2-agonists. • Avoid seizurogenic drugs. • Preoxygenate. • IPPV should be avoided with hypotension. • Heat support • Intermittent PCV, TP, and BG intraoperative monitoring • Blood pressure monitoring • Arterial blood gases in portalcaval shunts monitoring • Caution with intraoperative analgesics due to ↑ liver metabolism • Liver function tests postoperative Liver/Hepatic Disease • Portal-caval shunt • Coagulation profile • Complete blood evaluation 13 448 SECTION FIVE: ANESTHESIA AND ANESTHETIC PROCEDURES Table 13.2 / Case-Based Anesthesia (Continued) Preoperative Examination and Diagnostic Tests Potential Complications Recommended Anesthetic Protocols Anesthetic Alterations Special Surgical Care and Recovery Neonatal • A patient under 3 months of age • No special considerations • • • • • • • • Bradycardia Hypoglycemia Hypothermia Hypotension Hypovolemia Hypoxemia Inadequate organ function Pulmonary edema Preanesthetic • Atropine or glycopyrrolate • Neuroleptanalgesics Induction • Ketamine and diazepam • Propofol • ↓ Drug dose by 30–50%. • Allow longer time for response to drugs. • Neonates have a higher oxygen consumption, yet anesthetic concentrations are the same as for adults. • ↑ Sen