Rodents such as rats and gerbils as well as wild canines such as foxes are frequently implicated in outbreaks of the disease. Hosts in the Old World are frequently colonial, sedentary and live in sheltered burrows, caves, or even houses. Hence, the cause of an outbreak of the disease can usually be traced to a specific site. New World parasites infect hosts that do not live in colonies, are frequently nomadic, and live in forests. Urbanization, particularly in the New World, has enhanced transmission of the parasite from primary hosts to humans.
Animals infected by parasites can show a variety of symptoms.
A number of techniques exist for diagnosing animal leishmaniases. References Cited Bray, R. S. 1974. Zoonoses in leishmaniasis. In Parasitic zoonoses, clinical and experimental studies. E. J. Soulsby.