Primary right ventricular cardiac haemangiosarcoma with pulmonary metastases in a domestic short‐haired cat

Abstract A 5‐year‐old, male, neutered, domestic short‐haired cat presented for lethargy and anorexia and was diagnosed with a cardiac tumour and likely pulmonary metastases by ultrasonography and contrast computed tomography of the thorax. Clinically, the cat presented with right‐sided heart failure, pleural and pericardial effusion and ensuing tachypnoea, considered most likely the consequence of severe loss of functional myocardium of the right ventricular free wall. Euthanasia was elected due to poor prognosis. Postmortem examination confirmed the presence of a mass obliterating the right ventricular free wall and multiple pulmonary masses. Histological examination (including immunohistochemistry) revealed these to be of endothelial origin, thus representing a primary right ventricular free wall haemangiosarcoma with pulmonary metastases. Such presentations commonly are observed in dogs to date, however, had not been described in cats.