Rabies is a rare disease in horses, but they are highly susceptible to infection if exposed. The most common method of transmission is from certain wild animals, in the United States – skunks, raccoons, foxes, and bats are the most commonly infected wild animals. Bats that have been tested for rabies virus in Washington and Idaho have commonly tested positive for the disease. Domestic dogs and cats can transmit the disease to horses as well.
The rabies virus attacks the nervous system. Signs of the disease are variable and can mimic the signs of other diseases. Horses may show weakness, incoordination, salivation, lameness, colic, and or fever. They are rarely aggressive. There is no treatment and it is always fatal.
Many horses appear to have something wrong with their mouths or throats when infected. They will salivate excessively. If the unsuspecting examiner gets any of this saliva (or blood) in an open wound, the possibility exists for transmission.
If you suspect that your horse has been bitten by a wild animal, contact your veterinarian right away. Prevention of rabies is by annual vaccination with a vaccine licensed for use in horses, beginning at three months of age. Vaccines contain a killed form of the virus and appear to be safe and effective. Many owners fear that the vaccine could cause rabies in the horse, but this is not the case with current vaccines on the market. Although the incidence of rabies in horses in the Northwest is rare, horse owners should be aware that vaccination is an option.