Primary chondrosarcoma in the pulmonary artery of a dog.

A 5-year-old cross-bred dog was examined with an 8-week history of coughing and a 3-week history of collapsing during exercise. Thoracic radiography revealed moderate right-sided cardiomegaly and a partially mineralized area over the dorsocranial heart base. Echocardiography demonstrated moderate eccentric and concentric right ventricular hypertrophy and a hypoechoic mass in the main pulmonary artery. The owners declined further investigations and the dog died at home 4 days later. Postmortem revealed a primary pulmonary artery chondrosarcoma. This is the first case report of a pulmonary artery chondrosarcoma in a dog and presents another differential diagnosis of syncope in the dog.