Antemortem diagnosis of renal haemangiosarcoma in a Hanoverian gelding

Haemangiosarcoma is an uncommon neoplasm in horses that is rarely diagnosed antemortem. A 27-year-old Hanoverian gelding was presented to the Michigan State University Veterinary Medical Center for evaluation of lethargy, weight loss, stiffness and more recent colic signs. At presentation, the gelding was alert with mild tachycardia (60 beats/min). Other physical findings were normal except for a mass detected in the area of the left kidney on rectal palpation. Laboratory analyses revealed anaemia, hypoproteinaemia, hypoalbuminaemia and hyperbilirubinaemia consistent with haemorrhage and haemolysis. Transabdominal ultrasonography revealed the left kidney to be an enlarged heterogenous mass, and numerous 1-2 cm diameter hyperechoic nodules (without shadow artefacts) were imaged within the right kidney. After inconclusive results were returned on percutaneous biopsy of the left renal mass, a right renal biopsy yielded a diagnosis of haemangiosarcoma. Palliative care was initiated with dexamethasone, but 19 days after hospital discharge the gelding became recumbent, and humane euthanasia was performed. Necropsy examination confirmed disseminated haemangiosarcoma including both kidneys, adrenal glands, spleen, heart and lungs with the largest neoplasm in the left kidney.