A 6-year-old female arctic fox was diagnosed with a pyometra, which was addressed surgically. Preoperatively, the fox‘s hematocrit decreased from 26% to 10%. Her complete blood count revealed a marked nonregenerative anemia with ghost cells and spherocytosis, supporting an immune-mediated hemolytic anemia (IMHA) in addition to moderate blood loss. PCR tests for canine vector-borne pathogens were negative. Immunosuppressive therapy and supportive care were instituted. Pre-transfusion major crossmatch was compatible with a domestic dog (Canis lupus familiaris), that was DEA 1 and 3 negative, but DEA 4, 5, 7 and Dal positive. Two xenotransfusions (17 ml/kg) were administered without complication 24 hours apart using leukoreduced packed red blood cell. Six days post-transfusion, major crossmatch between the fox and the blood donor was now incompatible. Extended blood typing of the fox (DEA 1, 3, 7 negative, but DEA 4, 5 and Dal positive) could not explain the incompatibility. All subsequent crossmatches remained incompatible, with a maximum agglutination titer of 512 documented on day 13 and alloantibodies still detectable eight months post-transfusion (titers: 8–32). Discontinuation of immunosuppressive treatments one week post-surgery resulted in a recurrence of IMHA within three days. Therefore, prednisolone and cyclosporine were resumed and tapered over eight months with no further recurrence. Rare cases of hemolytic anemia have been reported in wild Canidae.1-3 Given its clinical presentation, this case of IMHA was likely triggered by a pyometra. Xenotransfusion can be considered in arctic foxes but should be planned with care; subsequent xenotransfusions may lead to severe hemolytic transfusion reactions.
The authors would like to thank the blood bank of the Centre hospitalier universitaire vétérinaire, Université de Montréal, all the clinicians, technicians, residents, interns, students and the staff of the Aquarium du Québec for their assistance in the care of this arctic fox.
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