Canine babesiosis is an important tick-borne disease that is characterized by acute onset hemolytic anemia and thrombocytopenia. Over the last 10 years five cases of Babesia spp. have been diagnosed in maned wolves (Chrysocyon brachyurus) in U.S. zoos. Common presenting clinical signs are acute onset inappetence, vomiting, distended abdomen, and lethargy. Physical exam findings include icteric, pale mucous membranes, hypothermia, hyperthermia, severe dehydration, and brown to port-wine urine.5,6 Clinical pathology usually reveals a severe hemolytic anemia with profound parasitemia on blood smears, thrombocytopenia, elevated urea nitrogen, hyperbilirubinemia, hypocalcemia, and hypokalemia.5
Five cases originating from Fossil Rim Wildlife Center have been diagnosed in the last two years. One male and two females were diagnosed postmortem.5 Three were successfully treated with atovaquone and azithromycin.1,3 All cases presented with acute clinical signs, with PCVs ranging from 2–9%. Blood smears were conducted on site and confirmed babesiosis. Based on sequencing of partial 18S ribosomal RNA genes, the Babesia spp. is most similar (99.6% identity) to a B. microti-like parasite identified in raccoons (Procyon lotor).2 The dam of all five was found to be negative on PCR testing and negative for clinical signs, raising the question of transplacental transmission.4 Surveys to the maned wolf holding institutions were sent December 2013. One female at Houston Zoo was found to have a Babesia titer of 1:32, which was found when she presented with seizures. Blood smears and PCR testing have shown to be helpful for confirmation of disease, but unsuccessful for regular screening.
The authors would like to thank all institutions who participated in the survey: Abilene Zoo, Alexandria Zoological Park, Audubon Park and Zoological Garden, BREC’s Baton Rouge Zoo, Denver Zoological Garden, Zoo Boise, Fossil Rim Wildlife Center, Connecticut’s Beardsley Zoo, Houston Zoological Gardens, John Ball Zoo, Birmingham Zoo, Lee Richardson Zoo, Dickerson Park Zoo, Buffalo Zoological Gardens, Little Rock Zoo, Oklahoma City Zoo, Philadelphia Zoo, Phoenix Zoo, Louisville Zoological Garden, Los Angeles Zoo, Montgomery Zoo, Smithsonian Conservation Biology Institution, Rolling Hills Zoo, Pueblo Zoo, National Zoological Park, San Diego Zoo, Natural Science Center, Sedgwick County Zoo, Wildlife Safari, Endangered Wolf Center, Sunset Zoological Park, and White Oak Conservation Center.
1. Birkenheuer AJ, Levy MG, Breitschwerdt EB. Efficacy of combined atovaquone and azithromycin for therapy of chronic Babesia gibsoni (Asian genotype) infections in dogs. J Vet Intern Med. 2004;18(4):494–498.
2. Birkenheuer AJ, Neel J, Large E, Barger A, Levy MG, Breitschwerdt EB. Molecular characterization of a Babesia spp. identified in a North American raccoon. J Wildlife Dis. 2006;42(2):375–380.
3. Di Cicco MF, Downey ME, Beeler E, Marr H, Cyrog P, Kidd L, et al. Re-emergence of Babesia conradae and effective treatment of infected dogs with atovaquone and azithromycin. Vet Parasitol. 2012;187(1–2):23–27.
4. Fukumoto S, Suzuki H, Igarashi I, Xuan X. Fatal experimental transplacental Babesia gibsoni infections in dogs. Int J Parasitol. 2005;35(9):1031–1035.
5. Phair KA, Carpenter JW, Smee N, Myers CB, Pohlman LM. Severe anemia caused by babesiosis in a maned wolf (Chrysocyon brachyurus). J Zoo Wildlife Med. 2012;43(1):162–167.
6. Simoes PB, Cardoso L, Araujo M, Yisaschar-Mekuzas Y, Baneth G. Babesiosis due to the canine Babesia microti-like small piroplasm in dogs—first report from Portugal and possible vertical transmission. Parasit Vectors. 2011;4:50.