This article discusses a challenging case from initial presentation, stabilisation and treatment to relapse. The case had an inconclusive diagnosis and differentials of hemangiosarcoma or immune-mediated haemolytic anaemia. The case progression included intensive medical management and a whole-blood transfusion with an excellent outcome. The patient, Patch (8-year-old male neutered Jack Russell Terrier), presented with history of lethargy and sudden onset of inappetence. Clinical symptoms alongside a MPCV 19%, RBC 0.25, haemoglobin 63, high platelets and borderline basophils.