Rabies is a deadly disease caused by a virus that attacks the nervous system. The virus is secreted in saliva and is usually transmitted to people and animals by a bite from an infected animal. Less commonly, rabies can be transmitted when saliva from a rabid animal comes in contact with an open cut on the skin or the eyes, nose, or mouth of a person or animal. Once the outward signs of the disease appear, rabies is nearly always fatal.
Only mammals can get rabies; birds, fish, reptiles and amphibians do not. In the United States, most cases of rabies occur in wild animals—mainly skunks, raccoons, bats, coyotes, and foxes. In recent years, cats have become the most common domestic animal infected with rabies. This is because many cat owners do not vaccinate their cats and cats can be exposed to rabid wildlife, either outdoors or when bats get into the house. Rabies also occurs in dogs and cattle in significant numbers and, while not as common, has been diagnosed in horses, goats, sheep, swine and ferrets.
Vaccination programs and control of stray animals have been effective in preventing rabies in most pets. Approved rabies vaccines are available for cats, dogs, ferrets, horses, cattle and sheep. Licensed oral vaccines are also being used for mass immunization of wildlife, particularly raccoons.
Once the rabies virus enters the body, it travels along the nerves to the brain. Animals with rabies may show a variety of signs, including fearfulness, aggression, excessive drooling, difficulty swallowing, staggering, paralysis and seizures. Aggressive behavior is common, but rabid animals may also be uncharacteristically affectionate. Horses and livestock with rabies also may exhibit depression, self mutilation, or increased sensitivity to light. Rabid wild animals may lose their natural fear of humans, and display unusual behavior; for example, an animal that is usually only seen at night may be seen wandering in the daytime.
Although the most common signs of rabies are behavioral changes and unexplained paralysis, rabies should be considered in all cases of unexplained neurological disease. There is no treatment once the clinical signs of rabies appear.
Rabies infection of an animal can only be confirmed after death, through microscopic examination of the animal’s brain.
Rabies remains a major concern worldwide, killing around 59,000 people every year. Almost all of these deaths are due to rabies transmitted by dogs in countries where dog vaccination programmes are not sufficiently developed to stop the spread of the virus.
Rabies vaccination and animal control programs, along with better treatment for people who have been bitten, have dramatically reduced the number of human cases of rabies in the United States. Most of the relatively few human cases in this country have resulted from exposures to bats; any contact with bats, even if a bite was not noticed, should be reported to your physician. Extremely rare cases have resulted from corneal or organ/tissue transplants from an infected donor. Dogs are still a significant source of rabies in other countries, particularly in Asia and Africa, so travelers should be aware of this risk and seek medical advice about vaccination prior to traveling outside of the United States.
Remember that rabies is entirely preventable through vaccination.
Bait containing rabies vaccine is commonly used for mass wildlife immunizations. The bait does not pose a health risk to you or your pets, but it is best to leave the bait undisturbed.