Illinois agriculture and health officials reported in early January that a LaSalle County horse tested positive for rabies at the Illinois Department of Agriculture laboratory in Galesburg on Dec. 10, 2004. Eleven people received preventive rabies treatment following exposure to the horse. Another domestic animal rabies case–a cow–was confirmed in eastern Bureau County on Jan. 13.

Tests on brain samples from the horse and the cow revealed that the virus infecting the animals was a skunk strain of rabies.

“It was important to us to find out whether it was the bat strain or the skunk strain, since the skunk strain can result in epidemics in the skunk population, which can spill over into other animals,” said state public health veterinarian Connie Austin, DVM, MPH. Any wild animal, like a raccoon, skunk, fox, coyote, or bat, can have rabies and transmit it to people. Currently, bats are the primary mammal positive for rabies in Illinois.

Clinical signs in an equine rabies case range from aggressive behavior to depression and neurologic signs. Also, progressive gait abnormalities, incoordination, lameness, colic, hypersensitivity, or fever could be signs of rabies, all of which can complicate diagnosis. According to Austin, the equine case was difficult to diagnose because it was atypical–the horse didn’t want to eat and had severe constipation. The probable source of the illness was a bite from a skunk