was made: “The edges of the liver lobes were rounded and the caudal aspect of the liver extended to….” The features (shape, position, color, consistency) should also be noted if the liver is abnormal. In this same example, the objective gross diagnosis is “hepatomegaly,” or large liver. Knowing if a liver is too big or too small is useful, as the differential causes are entirely different, but the interpretation of organ size based on weight relies on its comparison (ratio) with the bodyweight of the animal.
If an organ or system was not examined, this should also be noted (e.g. if only the abdominal cavity and gastrointestinal system were examined and sampled, there should be a note on the report saying that organs within the thoracic cavity were NOT examined).
5.3.2.2 Photographic Data
Visual data can have great importance in the communication of necropsy findings, and with digital hegemony, most shelters own or have access to a digital camera. Photographic data is complementary to the written description of a lesion and can be even more persuasive than a written report in the legal documentation of findings. A photograph should never be substituted for a written record since two‐dimensional photographs can only rarely fully represent the texture, cut surface, depth, and extent of any single lesion or systemic process.
5.4 Steps in Performing a Necropsy
5.4.1 The Materials Needed for a Necropsy
Not all the listed equipment will be needed to perform each necropsy, but Table 5.2 is a good starting list of the things that should be on hand for any given situation. Maintaining a devoted “necropsy kit” can save time.
5.4.2 General Information
There is no single CORRECT method to perform a necropsy, but consistency is important. If a cadaver is opened in the same way for each necropsy, one is more likely to recognize/discriminate abnormalities of any sort (e.g. size, position, color). Even in the case where the animal's disease appears to be limited to, for example, the respiratory system, the author recommends that the animal's body be opened in the same way so that both body cavities are examined visually. Respiratory distress can arise from abnormalities in organs not present within the thoracic cavity. In addition, concurrent diseases, if present, can be very important to disease progression. The most common example of this seen in shelters is immunosuppression caused by viral diseases like canine distemper virus, which can predispose a dog to a “secondary” infection such as bacterial pneumonia, or parvovirus (panleukopenia) in a dog or cat, which can predispose the infected animal to other enteric pathogens.
Table 5.2 Necropsy kit.
| 1) Camera |
| 2) Notebook or Pathology Form |
| 3) Protective clothingGloves (latex, nitrile, or rubber)BootsMask (to cover mouth and nose)Eyewear or goggles |
| 4) InstrumentsSharp knife (and/or scalpel)Knife sharpenerScissorsForcepsSmall shearsRuler |
| 5) Collection gearSpecimen container (plastic) with a tight‐fitting lid for fixed samples (plastic tubs, Rubbermaid, specimen cups, Tupperware type)10% buffered formalin (for fixed specimens/histology)Plastic bags with closure (whirl‐pack, zip‐lock) for unfixed samples (fresh or frozen)Tags (to identify specimens)Collection vials (can be used for urine, blood, joint fluid, etc.) |
| 6) Transport/shipping containersIce packsHeavy‐duty bags, or leak‐proof containersPacking material (preferably absorptive) |
| 7) Cleaning and disinfecting materials |
Step by step instructions on how to perform a necropsy are available from several books and web‐based sources. Five sources are listed below. While not all these protocols specifically use dogs and cats as models, the general approach to a necropsy is similar in all domestic species. The 5th listed resource by Severidt, for example, although specifically addressing cattle, has an excellent section on sample handling and submission.
5.4.2.1 Resources for Performing a Complete Necropsy
1 The Veterinary Necropsy Report Checklist and Guidelines form (DD Form 1626) was created by the Armed Forces Institute for Pathology (AFIP), Division of Veterinary Pathology. It can be found at https://www.esd.whs.mil/Portals/54/Documents/DD/forms/dd/dd1626.pdf (or search veterinary pathology, Form 1626).It is a comprehensive, 12‐page document with sections for data and interpretation (pages 1‐2), gross necropsy findings (pp. 3–8) and a detailed necropsy protocol (pages 9‐12). Included is a tissue checklist (page 7) to record tissues collected during the necropsy.
2 The Necropsy Book by Drs. John M. King, Lois Roth‐Johnson, David C. Dodd and Marion E. Newsom. This succinct, small book guide is available from the Charles Louis Davis‐Thompson Foundation, which is a non‐profit organization for the advancement of comparative pathology education. It is widely used by veterinary schools to teach basic necropsy techniques to veterinary students. It is an inexpensive manual and contains an organ‐based approach to a necropsy, including many drawings. The information on patterns is particularly useful for making the best decisions during the gross necropsy for sample collection. It is available at http://store.cldavis.org/thenecropsybookfifthedition.aspx
3 Necropsy Guide for Dogs, Cats, and Small Mammals, 1st Edition by Sean P. McDonough and Teresa Southard (editors). This book has “how‐to” guides, but also has many very useful photos of common diseases, common artifacts, and methods of fixation and sampling.
4 Necropsy of Wild Animals by Linda Munson DVM, Ph.D. This is a PDF document available on the web, composed by Dr. Linda Munson, and maintained by the University of California's Wildlife Health Services. It can be found at http://www.cldavis.org/ghpn/tools/Necropsy%20of%20Wild%20Animals.pdf. It is an excellent reference for the steps in a complete necropsy, including drawings, and the “models” are felines and canids. The site includes a comprehensive tissue checklist for the collection of samples during a necropsy.
5 Dairy Cattle Necropsy Manual by Julie Severidt, Dennis Madden, Gary Mason, Frank Garry, and Dan Gould. This is a web‐based set of directions, with color photographs, for a necropsy of a ruminant. It is available from Colorado State at http://csu‐cvmbs.colostate.edu/Documents/ilm‐dairy‐cow‐necropsy‐manual.pdf. It has a well thought out discussion of considerations for sample shipping. See Table 5.3
5.4.2.2 Opening the Animal for Analysis and Sampling
It is important to think about the samples that should be collected PRIOR to the necropsy and have materials at hand that are necessary for collection. Samples destined for microbiology or other infectious disease diagnostics should be taken first, with sterile instruments if possible, and with minimal handling. If a sample needs to be refrigerated or frozen, do so as soon as possible after collection. While many pre‐mortem tests can be performed postmortem, tissues collected postmortem, if collected properly, can be more accurate for establishing the cause of disease. For example, a culture of lung tissue to diagnose a bacterial cause of pneumonia is more accurate than a culture from an oropharyngeal swab that would contain several potential commensal bacteria.
Table 5.3 Resources for performing