Isaac, a two year old male intact Cocker Spaniel, presented to the Cornell University Hospital for Animals with a three week history of progressive lethargy and inappetance, an acute history of vomiting, and dark urine. Physical examination revealed pale mucous membranes, a grade III/VI systolic heart murmur, enlarged prostate gland, splenomegaly, and prominent popliteal lymph nodes. Bloodwork and urinalysis disclosed moderate regenerative anemia with spherocytes and autoagglutination, severe thrombocytopenia, hyperbilirubinemia, neutrophilia with a left shift, hyperglobulinemia, and bilirubinuria. Isaac was diagnosed with immune-mediated hemolytic anemia and thrombocytopenia and subsequently initiated on immunosuppressive medications, gastroprotectant drugs, an antimicrobial agent, and an anti-thrombotic medication. Response to treatment was monitored with gradual tapering of the immunosuppressive polypharmacy as indicated.