The disease develops slowly over 10 days to several months. Infected animals may withdraw and avoid contact with people and animals. Others become unnaturally aggressive and may attack. Death always occurs once a rabies-infected animal shows signs of disease. In North America, most rabies exists in wildlife, especially raccoons, skunks, foxes, and bats.
Rabies is spread by bites or saliva of infected animals.
Therefore, an unvaccinated cat involved in a fight with a wild animal or with wounds from an unknown animal should be suspect for rabies. If humans are infected, they can be vaccinated successfully in early stages of the disease. Treatment, however, is unpleasant and costly. Cats should be vaccinated for rabies at 12 weeks or older and again each year or every three years, depending on the vaccine used. Some states require vaccination every year.