Myxomatosis

Myxomatosis is a disease caused by Myxoma virus, a rabbit poxvirus in the genus Leporipoxvirus. The natural hosts are tapeti (forest cottontail, Sylvilagus brasiliensis) in South and Central America, and brush rabbits (Sylvilagus bachmani) in North America. The myxoma virus causes only a mild disease in these species, but causes a severe and usually fatal disease in European rabbits (Oryctolagus cuniculus), the species of rabbit commonly raised for companionship and as a food source.

Myxomatosis is an example of what occurs when a virus jumps from a species adapted to the virus to a naive host, and has been extensively studied for this reason. The virus was intentionally introduced in Australia, France, and Chile in the 1950s to control wild European rabbit populations.