1 Cardiomyopathy in cats is usually of the hypertrophic variety and associated with thickening of the walls of the heart. Thrombi develop within the chambers due to abnormal blood flow within the heart. Altered blood flow is one factor in development of thrombosis. In posterior vena caval thrombosis in cattle, the thrombus usually arises within the vena cava as it passes over the liver and develops due to phlebitis resulting from an underlying liver abscess . Embolism from the thrombus leads to inflammation within pulmonary arteries which may become weakened and dilated, leading to the formation of an aneurysm .
Hypertension develops and pulmonary haemorrhage frequently develops.
Damage to blood vessels is another of the mechanisms of thrombosis. Anticlotting factors such as antithrombin III may be lost and thrombosis may develop, commonly in the pulmonary artery. Alteration in the levels of clotting factors is the third main factor in development of thrombosis. . . .