Changes

Cardiac thrombosis is usually valvular, but can occasionally be mural.

Cardiac thrombosis is usually valvular, but can occasionally be mural.

In farm animals, and rarely in the horse, infective/ inflammatory thrombosis occurs subsequent to endocarditis. In dogs and horses, cardiac thrombosis is generally of degenerative/ non-infectious cause; endocarditis may occur, though uncommonly.  

In farm animals, and rarely in the horse, infective/ inflammatory thrombosis occurs subsequent to endocarditis.

There are important effects of cardiac thrombosis:

Cardiac thrombosis is generally of degenerative/ non-infectious cause; endocarditis may occur, though uncommonly. There are important effects of cardiac thrombosis:

# Distortion of valve cusps leads to mechanical effects which cause ineffective closure (incompetence), and distortion and enlargement of the valves by the thrombus mass causes narrowing of the valve outflow (stenosis). These effects lead to a progressive inefficiency of cardiac pumping and give rise to [[Venous Congestion and Hyperaemia - Pathology#Generalised (Systemic) Venous Congestion|general venous congestion]], [[Oedema - Pathology|oedema]] and circulatory failure.

# Distortion of valve cusps leads to mechanical effects which cause ineffective closure (incompetence), and distortion and enlargement of the valves by the thrombus mass causes narrowing of the valve outflow (stenosis). These effects lead to a progressive inefficiency of cardiac pumping and give rise to [[Venous Congestion and Hyperaemia - Pathology#Generalised (Systemic) Venous Congestion|general venous congestion]], [[Oedema - Pathology|oedema]] and circulatory failure.

# Emboli can be disseminated from the thrombus mass. If the lesion is on the left side of the heart, emboli are disseminated systemically and become trapped in the capilarry beds, e.g. of the kidney and spleen. The blockage leads to local ischaemic necrosis. If the lesion is on the right side of the heart, there is pulmonary dissemination.

# Emboli can be disseminated from the thrombus mass. If the lesion is on the left side of the heart, emboli are disseminated systemically and become trapped in the capilarry beds, e.g. of the kidney and spleen. The blockage leads to local ischaemic necrosis. If the lesion is on the right side of the heart, there is pulmonary dissemination.