Rabies is caused by a virus that attacks nerve tissue. The disease develops slowly over 10 days to several months. Death always occurs once a rabies-infected animal shows signs of disease. Furious rabies, where the animal often becomes unnaturally aggressive. 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 dog or cat involved in a fight with a wild 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. Each of these dog diseases is easily prevented by making sure your dog's vaccinations are current. Veterinarians will often give a single shot that contains vaccines for all three diseases.