An 18 month old female spayed domestic ferret presented to the Cornell University Hospital for Animals for a blood transfusion, following a one-month history of non-regenerative anemia of unknown origin. Bone marrow aspirate cytologic evaluation was diagnostic for pure red cell aplasia, a presumptively immune-mediated disease targeting erythrocyte precursors. This disorder has been reported once previously in the ferret (Malka et al, 2010). The patient initially responded to immunosuppressive therapy with glucocorticoids (2 mg/kg) and cyclosporine (4 mg/kg). Cyclosproine levels one month after initiation were at toxic levels (<2100ng/ml); soon after, the patient developed severe hepatobiliary disease, refractory to treatment. The patient was euthanized 139 days post initial presentation. Post-mortem histological exmaination of the liver revealed biliary coccidiosis with Eimeria spp, a presumptively opportunisitc pathogen that has never been previously reported in adult ferrets.