In some areas of the country, wildlife rabies is very common. In horses, infection with rabies causes a wide variety of signs. They, too, may show aggressive behavior, but commonly they demonstrate less specific signs, such as colic, incoordination and lameness. It is very difficult to diagnose rabies in horses based on clinical signs. Consequently, it is very important to vaccinate horses in areas where wildlife rabies is common.
Several vaccines are available and appear effective.
Because of the possibility of a local tissue reaction, most manufacturers suggest administering the vaccine in the rump, rather than the neck. It also causes abortion in pregnant mares, usually in the last three months of pregnancy. Vaccines against this disease offer immunity for a relatively short period of time. A viral disease spread from birds to horse via mosquito. In the horse, the virus invades the central nervous system, causing deranged consciousness, blindness, circling, ataxia and paralysis.