Rabies in Farm Animals

By Barry Whitworth, DVM

In the first half of 2017, four cases of rabies have been diagnosed in cattle in Oklahoma. When most people think of rabies, they have visions of a foaming at the mouth, snarling, aggressive dog that attacks everything in sight. However, in farm animals, this is not always the case.

Many veterinarians at some time in their career probably receive a phone call that goes something like this. “Doc, I found this cow away from the herd yesterday. I got her to the lot. She seems a little depressed. She kept straining like she was constipated. She was having trouble swallowing and was a little bloated. My neighbor and I opened her mouth, but we could not find anything. We both ran our arms down her throat, but we could not find anything. I need you come out and take a look at her.”

Unfortunately, many producers have been exposed to rabies because they do not recognize that this animal was infected with the “dumb” form of rabies. Not all animals with rabies have the “furious” form of the disease.

Rabies is a virus in the genus Lyssavirus in the family Rhabdoviridae. The virus does not survive in the environment for very long. Most disinfectants will kill the virus. The disease is fatal to animals and humans. On very rare occasions, people have survived the disease. In experiments, animals have survived the disease. Surviving rabies may occur in wild animals as well.

Domestic animals are infected with the virus from wildlife reservoirs. In Oklahoma, the most common reservoir is the skunk. In the world, the estimation is that 50,000 to 60,000 people die each year of the disease. The few people who die of the disease in the United States are usually unaware that they have been exposed to the virus.

In order to be infected with the virus, an animal must come in contact with the saliva from a rabid animal. This normally occurs from a bite wound. The virus may gain entry by saliva coming in contact with a mucous membrane or a break in the skin. Aerosol transmission has been reported in laboratories and bat caves, but this is very rare.

Learn more in the August issue of OKFR!