Rabies is a viral disease of mammals (including humans) that causes progressive and almost always fatal inflammation of the brain. The disease is typically spread via the bite of an infected animal. The virus then infects the nerves at the site of the bite wound and then slowly ascends until it reaches the brain. Once the virus enters the brain clinical signs start to develop and can manifest in a variety of different symptoms, including aggression or other behavioral changes, paralysis, coma, and death. Once symptoms develop death occurs within 2-10 days in virtually all cases.
Regular vaccination of both pet and wildlife species has greatly decreased the incidence of rabies cases in people worldwide. However, approximately 59,000 people still die annually as a result of the disease, with the vast majority of cases occurring on the Asian and African continents. Human rabies cases have declined in the United States since the 1970’s and are now rare with only 1-3 cases typically reported annually. This is largely due to successful animal control and vaccination protocols, as well as the legal requirement to vaccinate pets against rabies in many states.
Washington State law mandates any pet dog, cat, or ferret must be kept up to date on the rabies vaccine. Specific vaccine requirements can vary slightly by county, but in King County pets must be legally vaccinated by 4 months of age, and then kept up to date with subsequent booster vaccines. Boosters are typically administered annually to every three years dependent on species and the specific vaccine administered. Failure to keep a pet current on the rabies vaccine may result in an extended quarantine period or even euthanasia (in rare cases) if a potential exposure or bite of a human occurs.
As a result of such stringent vaccine requirements bats, and no longer dogs or other wildlife, are the most likely species to transmit rabies in the United States. This is true in Washington State where bats are the only animal now known to carry rabies. Although cases in pets and people are uncommon, occasionally transmission occurs via contact with rabid bats. Any potential exposure to bats should be reported immediately to your local health department and should be discussed with your veterinarian (in cases of pet exposure) or health care provider (in cases of human exposure) as soon as possible.