Babesia spp. are protozoal organisms that parasitize erythrocytes, causing anemia in the host. B. canis and B. gibsoni are two organisms commonly known to infect dogs. Babesia canis is thought to cycle primarily between domestic dogs and Rhipicephalus sanguineus, the brown dog tick. Cases of canine babesiosis may present with a wide variation of severity of clinical signs, ranging from a hyperacute, shock-associated, hemolytic crisis to an inapparent, subclinical infection.