Canine pericardial effusion: pathophysiology and cause.

Pericardial effusion is the abnormal accumulation of fluid in the pericardial space. As the fluid volume and intrapericardial pressure increase, cardiac tamponade can develop. The most common causes of pericardial effusion include cardiac hemangiosarcoma, idiopathic pericardial effusion, and chemodectoma. Understanding the underlying cause is important in providing treatment recommendations and an accurate prognosis.