A 42-year-old hypothyroid shepherd presented with a progressive abdominal lump accompanied by nausea and abdominal fullness. In addition, he had worsening hypothyroidism, despite supranormal doses of thyroxine. Computed tomography of the abdomen was suggestive of a mass lesion in relation to the stomach. A resection of the mass was done and the histopathology was suggestive of gastrointestinal stromal tumor. After surgery, the patient became euthyroid. We believe the patient had consumptive hypothyroidism due to the tumor.