Rabies

The dog is a most important animal as a disseminator of rabies virus, not only to man but also to other animals. Wild carnivora may be infected and transmit the disease. In the United States, foxes and skunks are the most commonly involved. These animals are sometimes responsible for infecting domestic farm animals.

The disease in wildlife (especially skunks, foxes, racoons, and bats) has become more prevalent in recent years, accounting for approximately 85% of all reported cases of animal rabies every year since 1976. Wildlife now constitutes the most important potential source of infection for both human and domestic animals in the United States. Rabies among animals is present throughout the United States with the exception of Hawaii, which has remained consistently rabies-free. The likelihood of different animals contracting rabies varies from one place to the next. Dogs are a good example. In areas where public health efforts to control rabies have been aggressive, dogs make up less than 5% of rabies cases in animals. These areas include the United States, most European countries, and Canada.

However, dogs are the most common source of rabies in many countries. They make up at least 90% of reported cases of rabies in most developing countries of Africa and Asia and many parts of Latin America. In these countries, public health efforts to control rabies have not been as aggressive. Other key carriers of rabies include the fox in Europe and Canada, the jackal in Africa, and the vampire bat in Latin America.

In the United States, 60% of all rabies cases were reported in raccoons, with 4,311 rabid raccoons reported in 1992. The high number of cases in raccoons reflects an animal epidemic, or, more properly, an epizootic. The epizootic began when diseased raccoons were carried from further south to Virginia and West Virginia. Since then, rabies in raccoons has spread up the eastern seaboard of the United States. Concentrations of animals with rabies include coyotes in southern Texas, skunks in California and in south and north central states, and gray foxes in southeastern Arizona. Bats throughout the United States also develop rabies. When rabies first enters a species, large numbers of animals die. When it has been around for a long time, the species adapts, and smaller numbers of animals die.