any of a group of tick-borne (tick) diseases of animals caused by species of Babesia, protozoans that destroy red blood cells and thereby cause anemia. Cattle tick fever, from B. bigemina, occurs in cattle, buffalo, and zebu. Other Babesia species attack cattle, sheep, goats, horses, donkeys, swine, and dogs. Wild animals such as deer, wolves, foxes, wildcats, and pumas are susceptible to infections from certain Babesia species.

Mortality depends on the pest species and the resistance of the host; native animals often contract mild cases and recover with immunity. Various drugs can be used to clear the blood of the parasites. Because Babesia species are both host and vector specific, tick control plays an important role in reducing incidence.