Changes

====Gross====

====Gross====

For hyperacute cases, typically no specific lesions are found except general congestion of the carcass and a change in skin colour.

No specific lesions but congestion of the carcass and change in skin colour.

For acute cases there is often congestion of the carcass, in particular the spleen. The lungs are oedematous and petechiae may be found below the kidney, peritoneum and on the heart. Lymph nodes will also be swollen and haemorrhagic.

Congestion of the carcass, in particular the spleen, lungs are oedematous and petechiae may be found below the kidney, peritoneum and on the heart. Lymph nodes will also be swollen and haemorrhagic.

Skin discolouration is also often present.

Skin discolouration.

For chronic cases, growths on heart valves may be evident as well as changes in joint architecture.  Joint capsules will be thickened in the presence of granulation tissue and in some cases erosion of articular surfaces may have progressed to ankylosis.  

Growths on heart valves may be evident as well as changes in joint architecture.  Joint capsules will be thickened in the presence of granulation tissue and in some cases erosion of articular surfaces may have progressed to ankylosis.  

Necrotic skin lesions may also be present.

Necrotic skin lesions may be present.

====Histologically====

====Histologically====

Vegetative lesions on the heart valves consist of connective and granulation tissue.

Vegetative lesions on the heart valves consist of connective and granulation tissue.

Synovial lesions consist of macrophages and lymphocytes.

Synovial lesions consist of macrophages and lymphocytes and short gram positive rods may be seen in smears made from blood in the heart.

Short gram positive rods may be seen in smears made from blood in the heart.

==Treatment==

==Treatment==