Necropsy Guide for Dogs, Cats, and Small Mammals

Sean P. McDonough, Teresa Southard, Sean P. McDonough, Teresa Southard

• Publisher: Wiley-Blackwell
• Year: 2016
• ISBN:
  9781119115670
• Edition: 1
• Topic: Medicine
• Subtopic: Veterinary Medicine

Necropsy Guide for Dogs, Cats, and Small Mammals is a complete, practical resource for performing necropsies on dogs, cats, rabbits, rodents, and ferrets in the veterinary clinic, animal shelter, research laboratory, or in the field.

• Provides practical guidance on all aspects of performing an necropsy on dogs, cats, and small mammals and interpreting the results
• Presents more than 200 full-color images to demonstrate techniques and findings
• Offers step-by-step instructions for the necropsy process and collecting samples
• Includes an anatomy review, discussion of dissection techniques, and list of common artifacts and post-mortem changes for each organ system
• Supports veterinarians in performing a necropsy in any setting, including animal shelters, veterinary clinics, research laboratories, and in the field

Part I
Necropsy Fundamentals

1
Introduction to the Necropsy

1.1 What is a Necropsy?

A necropsy is a postmortem examination. By convention, this term is typically used to denote a postmortem examination of a non‐human animal, and the term “autopsy” is used for a postmortem examination of a human; however, the terms are essentially interchangeable, and some veterinary pathologists have argued for the use of a common term to increase communication in the age of “one medicine,” Both terms are derived from Greek words: autopsy is from the word autopsia, meaning the act of seeing for one’s self; necropsy is from the words nekros meaning dead and the suffix ‐opsis meaning sight. The word autopsy was used in the 1600s, and the word necropsy did not appear until about 200 years later, most likely to replace the two‐word term autopsia cadavaria, or to look for oneself at a dead body. We chose the term necropsy for this book because it is the term we use at Cornell, where the word is deeply rooted in the long‐standing tradition of veterinary pathology.

The term necropsy can be used broadly to encompass the entire set of diagnostic procedures that occur after an animal dies; however, in this book we will use the term to denote the macroscopic or gross examination of the carcass and the process of collecting tissues for histopathology and other ancillary tests. At Cornell and most diagnostic laboratories, the fee for a necropsy includes both gross examination and microscopic evaluation of the tissues collected during the necropsy; however, for a reduced fee, the formalin fixed tissues collected by a referring veterinarian or scientist can be processed and examined histologically (we call this type of case a “necropsy in a bottle”). If the clinician is willing to do the necropsy and collect the tissues, the necropsy in a bottle option is often an economically attractive alternative to shipping the carcass to a diagnostic lab.

In this text, the term prosector will be used for the person performing the necropsy.

1.2 Why do a Necropsy?

Necropsies are performed to determine or confirm the cause of death or reason for a condition necessitating euthanasia. A necropsy may be requested by an owner, a veterinarian, a drug or vaccine company, a biomedical researcher, or a law enforcement or other government agency. The common reasons for necropsy requests at Cornell are shown in Table 1.1.

Table 1.1 Reasons necropsies are requested.

Owner	Gain peace of mind, especially about a decision to euthanize Rule in or out infectious/toxic cause when other animals are at risk Suspicion of malicious action by another party (usually the neighbor) Suspicion of veterinary malpractice Concern about zoonotic disease (rabies) Insurance reasons (most common in horses)
Veterinarian	Find answers in a confusing or atypical case Confirm a suspected diagnosis Examine surgical sites or retrieve implanted devices Collect data about a condition of interest
Drug or Vaccine Company	Determine if drug or vaccine caused illness or death
Biomedical Researcher	Investigate cause of unexpected death in animal on a study Compare control and experimental animals at end of study
Law Enforcement or Government Agency	Animal harmed or killed during police activity Suspicion of criminal cruelty or neglect Suspicion of a pet‐food related toxicity

1.3 What Information Can and Cannot Be Gained from a Necropsy

A necropsy can result in a definitive diagnosis, a presumptive diagnosis or, if there are no gross lesions, will at least rule out some possible diagnoses.

Necropsies are particularly rewarding when they reveal pathognomonic gross lesions. These gross changes are specific for a particular disease entity and can often allow the prosector to make a definitive diagnosis with no need for additional testing. Some of these conditions are illustrated in Figures 1.1–1.6. Unfortunately, these cases make up only about 10% of our caseload at Cornell.

Figure 1.1 Segmental hemorrhagic enteritis in this 8‐week‐old kitten is virtually diagnostic for panleukopenia caused by feline parvovirus. The lesion in puppies with canine parvovirus infection is similar.

Figure 1.2 The wet form of feline infectious peritonitis often causes bright yellow, thick peritoneal effusion and multifocal tan to white plaques on the serosal surfaces.

Figure 1.3 Dark red foci on the capsular surface of the kidneys in a newborn puppy usually indicates infection with canine herpesvirus.

Figure 1.4 The gross finding of a distended, rotated, congested stomach is characteristic of gastric dilatation volvulus in a dog.

Figure 1.5 Long, slender tan nematode parasites in the right side of the heart and pulmonary artery are pathognomonic for heart worm infection (dirofilariasis).

Figure 1.6 A dark re...

Table of contents

• Cover
• Title Page
• Table of Contents
• List of Contributors
• Foreword
• Acknowledgments
• About the Companion Website
• Part I: Necropsy Fundamentals
• Part II: Organ Systems
• Part III: Special Cases
• Part IV: Additional Testing
• Appendix 1: Normal Organ Weights (Percentage Body Weight)
• Appendix 2: North American Diagnostic Laboratories
• Appendix 3: Tissue Collection Checklist
• Appendix 4: Describing Gross Lesions
• Index
• End User License Agreement