Geni Wren The National Association of State Public Health Veterinarians, Inc. has available the Compendium of Animal Rabies Prevention and Control, 2011.
This report provides recommendations for public health officials, veterinarians, animal control officials, and other parties engaged in rabies prevention and control activities and should serve as the basis for standardizing procedures among jurisdictions. These updated 2011 guidelines include the national case definition for animal rabies and clarify the role of the CDC rabies laboratory in providing confirmatory testing of suspect animals.
This is a good reminder to food-animal and equine veterinarians about the potential for rabies in cattle and horses. Common in the fall in many parts of the country are cattle and horses choking on hedgeballs falling from trees in pastures, and veterinarians, producers and horse owners alike have exposed themselves to rabies by reaching in the mouth of a supposedly choking animal that is really displaying clinical signs of rabies.
Clinical signs of rabies in cattle
Cattle with “furious” rabies can be dangerous, attacking and pursuing humans and other animals. Cattle with “dumb” or paralytic rabies have minimal behavior changes, but progress into paralysis.
Clinical signs of rabies can be varied in cattle and other animals. Some of the more common clinical signs include:
- Sudden change in behavior
- Progressive paralysis
- Abrupt cessation of lactation in dairy animals
- Abnormal bellowing
- Paralysis of the throat
- Head extension
- Choking behavior
The Compendium includes this information on rabies in livestock:
Livestock. All species of livestock are susceptible to rabies; cattle and horses are the most frequently reported infected species. Any illness in an animal exposed to rabies should be reported immediately to the local health and agriculture officials. If signs suggestive of rabies develop, the animal should be euthanized and the head shipped for testing as described in Part I.A.9.
- Unvaccinated livestock should be euthanized immediately. For animals that are not euthanized, on a case-by-case basis, they should be observed and confined for 6 months.
- Livestock exposed to a rabid animal and currently vaccinated with a vaccine approved by USDA for that species should be revaccinated immediately and observed for 45 days.
- Multiple rabid animals in a herd or herbivore-to-herbivore transmission are uncommon; therefore, restricting the rest of the herd if a single animal has been exposed to or infected by rabies is usually not necessary.
- Handling and consumption of tissues from animals exposed to rabies might carry a risk for rabies virus transmission. Risk factors depend in part on the sites of exposure, the amount of virus present, the severity of the wounds, and whether sufficient contaminated tissue has been excised. If an exposed animal is to be custom- or home-slaughtered for consumption, the slaughter should occur immediately after the exposure, and all tissues should be cooked thoroughly. Persons handling animals, carcasses, and tissues that have been exposed should use barrier precautions. Historically, federal guidelines for meat inspectors required that any animal known to have been exposed to rabies within 8 months be rejected for slaughter. The USDA Food and Inspection Service and state meat inspectors should be notified when such exposures occur in food animals before slaughter.
Rabies virus is widely distributed in tissues of rabid animals. Tissues and products from a rabid animal should not be used for human or animal consumption or transplantation. Pasteurization and cooking inactivate rabies virus; therefore, inadvertently drinking pasteurized milk or eating thoroughly cooked animal products does not constitute a rabies exposure.