Most necropsies do not require a specialized facility. Large animal veterinarians routinely perform necropsies in a pasture or a barn. In a small animal clinic or laboratory setting, a stainless-steel table with running water and plumbed to a sanitary sewer line is ideal. The area chosen should be easy to clean and disinfect. The necropsy should be performed at a time and place where there are minimal distractions and foot traffic so as to minimize the chances of cross contamination.

The instruments and supplies needed to perform a necropsy are relatively few and inexpensive. The major expense is the investment of an adequate amount of time to perform a complete necropsy. A kit assembled beforehand can facilitate the necropsy process. Next is a suggested list of equipment and supplies:

1. Sharp blade for cutting soft tissue: Knife, scalpel
   

   A sharp blade is the most important tool for the prosector. The choice between a knife and a scalpel should depend on availability, size of the animal, and personal preference. A good knife will hold its edge better than a scalpel blade and can be sharpened as needed. Correctly sharpening a knife requires considerable skill and patience. A wooden handle is porous and may absorb pathogens, so a synthetic handle that can be easily disinfected is preferred. A sharpening steel is essential to hone the blade after sharpening and to revive the edge after cutting for a while. The steel should be at least as long as the knife blade. Hold the knife crossways against the steel and tilt the blade until the cutting edge meets the shaft of the steel at a 22.5° angle (hint: hold the blade perpendicular to the steel and then cut the angle in half to 45°; cut the angle in half again to reach the correct angle). Gently draw the blade toward you while gliding it down the length of the steel (Figure 2.1). Repeat 10 to 12 times on each side and then rinse and wipe the blade with a cloth to remove any metal filings. Pull-through knife sharpeners, with the sharpening surfaces fixed at the appropriate angle, are also available. Always be careful when using any type of knife sharpener since inattention can result in serious injury.

   

   
   

   A scalpel is a good choice for the necropsy of a puppy, kitten, or small mammal. For a medium- to large-sized animal, a knife is usually the best choice for opening the carcass, while a scalpel can be used for more delicate dissection of the organs.

2. Sturdy instrument(s) for cutting bone and removing the brain: Bone cutting forceps, pruning shears, hedge clippers, oscillating saw, hand saw, coping saw, reciprocating saw, chainsaw
   

   A complete necropsy requires cutting the bones of the ribs and skull to access the viscera, as well as the femur to examine the bone marrow. The tools needed for cutting the ribs and skull depend on the size of the animal. Recommendations are included in Table 2.1 and illustrated in Figure 2.2. When using an oscillating saw or bone cutting forceps to remove the brain, the head can be held with the nondominant hand and rotated as needed. For the larger tools, and particularly power tools, a head vice (Figure 2.2d) is recommended. A T tool is very helpful for prying off the top of the calvaria after cutting the bone (Figure 2.3).

   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

   Size	To cut ribs	To cut skull	To remove skull cap
   Up to 2 kg	Scissors Bone-cutting forceps	Scissors Bone-cutting forceps	T tool
   2–50 kg	Bone-cutting forceps Pruning shears Hedge clippers	Bone-cutting forceps Oscillating saw* Coping saw	T tool
   50–100 kg	Hedge clippers	Oscillating saw* Hand saw	T tool Wedge and hammer
   Over 100 kg	Hedge clippers Reciprocating saw* Chainsaw*	Hand saw Reciprocating saw* Chainsaw* Bandsaw* (split the head longitudinally)	Wedge and hammer

   
   

   *Avoid using power tools in cases of suspected zoonotic disease (such as rabies) to prevent aerosolization of the infectious agent.

   

   

   
   
3. Dissection instruments: Forceps, scissors
   

   Forceps and scissors are helpful tools for dissecting and collecting soft tissue. Rat tooth forceps cause less tissue artifact in histologic sections than forceps that crush the tissue. Scissors with at least one blunt tip are very useful in opening the intestine and other tubular organs without damaging the tissue. The size of the dissection instruments should be scaled to the size of the animal.

   
   
4. Cutting board
   

   A standard synthetic kitchen cutting board provides a flat surface on which to section tissues and can be used as a background for photographs. Cutting tissues on the cutting board, rather than on a steel table, helps to keep your knife sharp.

   
   
5. Scale
   

   If possible, the body should be weighed prior to starting a necropsy. Small animals can be weighed on scales that are available in most clinics and laboratories. Weighing a large animal is more difficult and usually requires special equipment such as a crane scale attached to the hoist. In many cases, a recent weight is available from the clinic or owner. Weights of organs, such as the heart and liver, can also provide important information which may influence the diagnosis. A gram scale is a useful piece of equipment when performing a necropsy on a small animal, while a hanging scale, crane scale, or floor scale can be used for large animal organs. A variety of scales are shown in Figure 2.4. Data for normal organ weights (as a percentage of body weight) are included in Appendix 1.

   

   
   
6. Digital camera
   

   A digital camera is an amazing tool for recording and sharing findings from the necropsy examination; however, trying to keep the camera clean during the procedure can be difficult. Having a dedicated necropsy camera that remains on the necropsy floor at all times is one solution. The prosector can also wear two pairs of gloves and take the outer layer off when taking photos. Another option would be to invest in a relatively inexpensive waterproof case for your camera, tablet, or smart phone. A camera with a resolution of at least 5 MP should be adequate for gross photography. Photographs should be taken at varying distances (macro and micro) to orient the viewer to the location of lesions.

   
   
7. Materials for collecting histopathology samples
   

   Samples which will be submitted for histopathology should be collected in a wide-mouth, plastic, leak-proof container (Figure 2.5), with a final ratio of 1 part tissue to 10 parts fixative. The standard fixative is 10% neutral buffered formalin, which is available from any biological supply company. Other useful materials for collecting samples for histology (Figure 2.6) include:

   
   
   
   
   • Wooden tongue depressors to affix samples of nerve, skin, and muscle to help maintain proper orientation during fixation.
     
   • Plastic tissue cassettes to differentiate lymph nodes, identify small tissues, or mark specific lesions. If the tissue is small enough to be placed in a cassette without compression or crushing, do so. If not, clip the cassette to the edge of the tissue. Always label these cassettes with a #2 pencil; other types of markings will wash off in the formalin.