Article / Updated 03-26-2016
Rabies is caused by a viral infection of the nervous system. Most cases of rabies in the United States occur in wild animals. Because dogs share territory with wild animals, they're at risk of being bitten by a rabid wild animal. (Normally timid animals can become aggressive if rabid.) Most cases of rabies in dogs can be traced to skunks, foxes, raccoons, and bats, but any rabid mammal can transmit the disease.