Rabies in animals

In animals, rabies is a viral zoonotic neuro-invasive disease which causes inflammation in the brain and is usually fatal. Rabies, caused by the rabies virus, primarily infects mammals. In the laboratory it has been found that birds can be infected, as well as cell cultures from birds, reptiles and insects.^[1] The brains of animals with rabies deteriorate. As a result, they tend to behave bizarrely and often aggressively, increasing the chances that they will bite another animal or a person and transmit the disease.

In addition to irrational aggression, the virus can induce hydrophobia ("fear of water")—wherein attempts to drink water or swallow cause painful spasms of the muscles in the throat or larynx—and an increase in saliva production. This aids the likelihood of transmission, as the virus multiplies and accumulates in the salivary glands and is transmitted primarily through biting.^[2] The accumulation of saliva can sometimes create a "foaming at the mouth" effect, which is commonly associated with rabies in animals in the public perception and in popular culture;^[3][4][5] however, rabies does not always present as such, and may be carried without typical symptoms being displayed.^[3]

Most cases of humans contracting rabies from infected animals are in developing nations. In 2010, an estimated 26,000 people died from the disease, down from 54,000 in 1990.^[6] The World Health Organization (WHO) reports that dogs are the main source of human rabies deaths, contributing up to 99% of all transmissions of the disease to humans.^[7] Rabies in dogs, humans and other animals can be prevented through vaccination.