Babesia odocoilei infection in a North American elk (Cervus elaphus canadensis)

A 13-year-old, male, North American elk (Cervus elaphus canadensis) from a commercial herd was presented for a sudden onset of lethargy, anorexia, and hematuria to Palmer Veterinary Clinic, Plattsburgh, NY, USA. The elk, originated from Ohio, was from a herd of 60 animals with an age range of 2 months to 13 years. Clinically, over a 5-7-day period, the elk began to distance itself from the remainder of the herd, and became anorectic and eventually recumbent. Results of the admitting complete blood count indicated a normocytic, normochromic, nonregenerative anemia. The animal was serologically negative for elk wasting disease. Supportive treatment did not result in clinical improvement. The elk was euthanized because of the rapidly declining condition. At necropsy, the spleen was diffusely enlarged and the mesenteric and periaortic fats were yellow. Microscopically, the only finding of note was extensive splenic erythrophagocytosis. Microscopic examination of a peripheral blood film stained with Wright-Giemsa revealed that about 5% of erythrocytes contained protozoal parasites. The morphologic characteristics of these organisms were consistent with Babesia organism, most likely Babesia odocoilei. Using a nested polymerase chain reaction, the organism was identified as B. odocoilei. To the authors' knowledge, this is the first report of B. odocoilei infection in North American elk in New York State, USA. We recommend that infection with B. odocoilei be considered in any case of acute hemolytic anemia in elk. © 2012 Springer-Verlag London Limited.