Babesiosis in dogs is caused by Babesia canis and sbspecies are B. canis canis, B. canis vogeli, and B. canis rossi. Babesia gibsoni is also common in some areas. This is an uncommon disease that destroys red blood cells, producing a haemolytic anemia. One mode of transmission is by the bite of a dog tick. Natural hosts of this tick are various wild animals, particularly the white-footed mouse and the white-tailed deer. Because these animals are also implicated in Lyme disease, both diseases can occur at the same time. Babesiosis can also be transmitted by blood transfusions from infected animals. Outside the United States, the disease is found in tropical and subtropical regions throughout the world. For reasons unknown, the Greyhound is particularly susceptible to babesiosis. Most infections in dogs are subclinical. In dogs with acute illness, the signs are fever, enlargement of the spleen and liver, and abnormal blood tests are indicative of haemolytic anemia. The signs of anemia are shortness of breath, exercise intolerance, and pallor of the gums and tongue. The bone marrow and liver can be affected.

Diagnosis is contingent upon finding the protozoan in blood smears by microscopic examination. An IFA serum antibody test also is available.


Imidocarb is the only drug currently effective against canine babesiosis.


Prevent infection by controlling ticks, as described in Ticks.