Dr. Richard Wallace uses a graphic to explain the topography of the left side of a newborn calf, in terms of performing a necrospy, at a PDPW Calf Care Connection workshop held Nov. 19 in Eau Claire, Wis.
PHOTO BY DANIELLE NAUMAN
Dr. Richard Wallace uses a graphic to explain the topography of the left side of a newborn calf, in terms of performing a necrospy, at a PDPW Calf Care Connection workshop held Nov. 19 in Eau Claire, Wis. PHOTO BY DANIELLE NAUMAN
    EAU CLAIRE, Wis. – The saying goes, “If you have livestock, then you’re going to have deadstock.” Anyone who raises calves knows dealing with disease and calf mortality can be frustrating. Getting an accurate cause of death in calves is critical for developing successful preventative and treatment protocols.
    According to Dr. Richard Wallace, a veterinarian affiliated with Zoetis, a necropsy should be performed on all calves that die in order to confirm the diagnosis. The results of the necropsy will provide information to your veterinarian that will allow them to help you develop a plan for prevention and protocols to ensure proper treatment.
    “Ideally, I’d get there in the first 8 to 12 hours following death to perform a necropsy,” Wallace said. “However, if I have a lot of calls, obviously the live animals I can still do something for are going to come first.”
    The veterinarian’s inability to perform the necropsy in that crucial time period before bacteria start the decomposition process should not stop you from getting the answers you need. Anyone can perform a field necropsy and collect photographical evidence and tissue specimens for laboratory testing. Wallace recommends a team of at least two people to perform the necropsy; one to do the cutting and one to do the photographing and recording.
    To perform a field necropsy in the most efficient and clean manner, Wallace suggests you have the following supplies: a large plastic cart or table that will serve as a surface to perform the necropsy other than on the ground, latex-type gloves such as milking gloves, sharp knives, hedge clippers, a disposable scalpel or box cutter, 12cc syringes with 16 gauge needles, a plastic ruler, a Styrofoam cooler and cold packs, a necropsy report form that gives you a list of areas to examine, a phone with a camera, light string (stronger than kite string), zip-type, quart-sized freezer bags, a Sharpie marker and pencil, and twine to truss up the carcass after the necropsy. Wallace recommends a small plastic tool box to keep your necropsy supplies in.
    First, Wallace tells his clients to record the calf’s identification, date of birth, the vaccination status, feeding program, overall health history and the treatments that have been administered for what you suspect the problem was. He also recommends taking photographs of the ear tag. He suggests placing some type of common item, such as the ruler in each photo for reference of size.
    In order to make this messy job as neat as possible, Wallace recommends creating what he calls a necropsy bowl out of the carcass, noting the sooner the necropsy is performed after death, the easier the job will be.
    The first step is to lay the calf with its left side down on the table so the rumen is on the bottom. Wallace recommends using a shingle cutter to make a skin incision from the chin all the way down the body along the ventral midline. The incision should go above the navel and continue between the back legs.
    The front legs should be reflected by cutting through the arm-pit area where there is no boney joint. The hide should be skinned off the rib cage back to the rear legs, taking care not to cut into the gut. The rear leg should be lifted and the joint of the femur and hip should be disarticulated. Then, using a knife or hedge shears cut the rib cage along the sternum. This will give you the bowl-effect, keeping the carcass neat with the lungs in one section and the intestines in the other. At this time, Wallace recommends taking a picture of the entire carcass with the exposed cavities.
    Once the necropsy bowl is created, the first step is to begin examining the lungs for color and texture, taking photographs. A 2- by 2-inch section of any affected portion of the lung should be removed and placed in a labeled bag and placed immediately in the cooler. Then the trachea should be cut open and examined, looking for signs of mucous. The heart should be examined, noting if there is any fat deposited around it. A 1-inch cross section of the widest part of the heart should be removed and placed in a labeled bag.
    Next, the intestines, kidneys and liver should all be examined for color and fat deposits around them. Two- by 2-inch sections of the liver, spleen and kidneys should all be collected and placed in labeled bags. A section of small intestine, nearest the stomachs, should be collected for a tissue sample. To minimize the mess, Wallace suggests tying two strings around the intestine, about 1 inch apart. Then, moving 3-4 inches down the intestine, tie two more strings again 1 inch apart. Cut across the intestine, between each string that is 1 inch apart, making a small sausage-like sample of intestine to place in a labeled bag. The process should be repeated to take samples of the large intestine, only taking the sample closer to the rectum.
    Using the 12cc syringes, aspirate fluid from the abomasum and then the rumen, labeling each syringe and placing it in a separate bag. Finally, obtain a stool sample in a labeled bag.
    Once all of the tissue samples have been collected and photographs of anything unusual have been taken, fold the front and rear legs over into their original position. Using your knife, poke holes along the skin incision, and use the twine to lace up the abdomen to keep everything contained before disposing of the body.
    Performing your own field necropsy may at first seem daunting. However, with practice, Wallace assures producers they will appreciate the answers they gain in regards to their treatment and prevention protocols.