There is nothing more disheartening than the death of an animal. The economic loss of a productive cow or recently fresh heifer is significant, no question. On top of this, we have to deal with the disposal of the remains - another expense. The natural reaction is to put the incident behind us and move on to the never-ending list of things that need attention on the farm.
Unfortunately, a fatalistic view towards these losses keeps us from acting on the early warning signs of problems that should be addressed. How many death losses should it take to launch an effort to find the reason? Many diseases cause significant economic loss with few deaths.
Doing the Necropsy: Rumen acidosis is a classic example of a costly problem that rarely causes cow mortality in the short term. The potential for fatal consequences exists, but may take weeks to months to show. We tend to miss the connection between laminitis, abomasal ulcers, liver abscesses, lung abscesses, nosebleeds and overall poor condition, that are all connected to rumen acidosis. This is particularly true when they occur separately over a long period of time.
Making an accurate diagnosis on some of these maladies in the living animal is difficult. Most cases are shipped before they expire. Our best chance of figuring out the cause is often through examination of the internal organs, a process only practical through a necropsy (autopsy in the human world). How many lost animals are examined this way?
As a practicing veterinarian, necropsies were one of my least favorite things to do. The sights, smells and physical efforts involved with a mature cow in the middle of summer are something you don’t forget. In reality, however, this was the most valuable service I could offer to my clients on an otherwise worthless carcass. The thought of paying someone to do this is not a popular one for the dairyman. What to do with what is left of complete necropsy is another issue.
This situation often led me to make small incisions to get a peek or feel of internal goings on. Closing up the carcass so that the rendering truck would take it away limited the quality and diagnostic value of the process. This was an easier, faster, and cut-rate procedure. But, as the old saying goes “you get what you pay for”. Of course today you have to pay to have the remains carted off regardless of appearance.
Many dairymen are still not aware of the diagnostic potential that post-mortem investigation might offer. In light of some of the serious death loss and financial considerations this is surprising.
Pathogen deaths: Calf and adult deaths due to Clostridium perfringens often remain a mystery without diagnostic workup. This bacterium usually causes very sudden illness, intestinal damage, bloat and death. However, this picture is variable and the symptoms can be confused with other gut disease. Unfortunately, there are no blood tests for clostridium. Culturing the manure is next to useless. Only a fresh frozen sample of the affected small intestine from a recently expired animal is suitable to make the correct diagnosis at a state diagnostic lab. This sample may be critical as well if you are dealing with a strain that commercial vaccines will not protect against and opt to have a special autogenous bacterin made.
The looming problem with multi-drug resistant Salmonella dublin makes a strong case for necropsy work. Three herds in New York with numerous cases have now been confirmed. This is not your run of the mill Salmonella that we have been trying to ignore for many years. This often presents as pneumonia with high mortality rates, especially in calves 1 through 16 weeks of age. Without diagnostic work, these calves can easily be mistaken for Pasturella, Mycoplasma or even viral pneumonias.
Decision making: Here are a few factors to consider when working with your veterinarian and considering a necropsy:
- A near death animal that is euthanized will provide the best quality tissue samples.
- The longer an animal is dead, the more difficult it is to make an accurate diagnosis. Call your veterinarian as soon as you can.
- Keep the body out of the sun in the warm weather and avoid freezing in the winter.
- When taking fresh or frozen samples for the lab, it is best to be able to mail them off early in the week. Tissue samples may deteriorate when the package sits somewhere over the weekend. Select a candidate that dies early in the week.
- If you are close to a veterinary pathology lab, you might think about transporting the animal there for necropsy and other testing.
- Note as much history about the particular animal or other similarly affected ones.
- Composting animal remains in manure solids and bunker silo waste is relatively easy, odor free and environmentally friendly.