Rabies is almost always fatal once clinical signs appear, and the only humane course of action is euthanasia. Consult a veterinarian about the local laws and regulations concerning exposure or suspected exposure to rabies.
Currently, vaccinated animals that are suspected of being exposed to rabies should be re-vaccinated immediately and then strictly quarantined according to local laws -- generally for a period of 45 days. During the quarantine, the animal must be isolated in a secure enclosure from contact with other animals and people. Contact a veterinarian immediately if any contact with rabies is suspected.
Unvaccinated animals that have been exposed to rabies are a severe health hazard. Most states either recommend or mandate euthanasia and testing of unvaccinated exposed animals. If an owner refuses euthanasia, the animal must be held in strict quarantine for six months, with a vaccination administered at the fifth month. Animals that are not current with their rabies vaccination are generally evaluated on a case by case basis according to local laws.
Even an otherwise healthy, properly vaccinated domestic animal that bites a human should be reported to authorities -- generally the police or animal control -- and quarantined for a period of 10 days.
