Anastasia, a 9.5 year old, spayed female Vizsla presented to the Cornell University Hospital for Animals on 6/12/06 with a recent history of lethargy, weakness and inappetence. Upon physical examination, Anastasia was found to have extremely pale mucous membranes, tachycardia, tachypnea and an elevated temperature. Complete blood count revealed a severe non-regenerative anemia with mild spherocytosis. Anastasia was Coomb's test negative and had a positive ANA titer. Bone marrow cytologic evaluation showed a dramatically over-represented erythroid line. Metarubricytes and reticulocytes were essentially absent. These findings were likely the result of an immune-mediated attack on erythroid precursors in the bone marrow. A presumptive diagnosis of nonregenerative immune mediated anemia was made at that time and appropriate medical intervention was initiated. This paper describes the appropriate work-up and treatment of immune mediated anemia, using a clinical case as a model.