In the context of the catastrophic loss of livestock experienced during last weekend’s blizzard, questions arise about the public health risks due to the carcasses of animals that perished in the storm.
Whenever possible, proper disposal methods of burying, burning or rendering should be employed. When properly done, these methods mitigate any potential problems that may arise from dead carcasses. These methods eliminate the likelihood that carcasses can serve as an attractant for wildlife scavengers such as coyotes or skunks.
However, this weather event caused cattle death losses in areas such as draws and creek beds that cannot be easily or immediately accessed. Those carcasses may have to remain exposed to the elements until such time as they can be safely removed.
Unlike some large animal mortality events that have occurred worldwide, this event affected normal, healthy cows and calves. As such, these animals were not harboring infectious disease agents in sufficient quantities to pass to other animals, or in the case of zoonotic disease, to humans. While normal animals can occasionally harbor bacteria that could potentially cause illness in people, the concentration of these bacteria in normal range cattle is extremely low.
- Salmonella bacteria can be quite hardy in local environments but would not be expected to be significantly present in normal cattle.
- Campylobacter is less likely to persist outside the animal, and would not be expected to be present in large numbers in normal cattle.
- E. coli O157 is typically not found in adult cows or nursing calves to a significant extent.
- Cryptosporidia can be hardy in the environment but are not typically found in adult cows or calves older than one month of age.
- Cattle viruses such as IBR, BRSV, and BVDV do not affect humans and have a very short survival time outside a living animal.
Even in the rare case of animal carcasses harboring these agents, the action and flow of water through waterways will tremendously dilute these pathogens, making the risk to animals or people downstream negligible.
Likewise, animal carcasses can contribute to poor water quality through the products of their decomposition (increased dissolved solids, increased biological oxygen demand, etc.) but once again, dilution through normal water flows typically mean there is little to no effect on water quality downstream.
Leaving carcasses in waterways is never an acceptable disposal solution. However, in cases where these animals cannot be immediately accessed, significant risks to public or animal health should not be expected.