Pericardial effusion in a dog with rhabdomyosarcoma in the right ventricular wall.

A seven-year-old male labrador retriever presented in right heart failure with weak femoral pulses, and pleural, abdominal and mild pericardial effusion. No diagnosis could be established initially. Two days later, the dog developed severe pericardial effusion causing cardiac tamponade. A tumour in the right ventricular wall was visualised on ultrasonographic examination. An exploratory thoracotomy was performed and biopsies of the mass submitted for histopathological examination. A diagnosis of rhabdomyosarcoma arising from the myocardium was established. Cardiac rhabdomyosarcoma has been reported in only two dogs. Neither report was associated with pericardial effusion.