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[[Image:Black leg myositis.jpg|right|thumb|300px|<small><center>Blackleg myositis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

[[Image:Black leg myositis.jpg|right|thumb|300px|<small><center>Blackleg myositis (Image sourced from Bristol Biomed Image Archive with permission)</center></small>]]

A bacterial disease affecting cattle and sheep caused by [[Clostridium chauvoei|''Clostridium chauvoei'']]. Spores pass through the wall of the GI tract and via the bloodstream enter the muscle and liver where they then lie latent. This results in oedematous and crepitant swelling of the muscles. Under the correct conditions (usually anaerobic following injury) they germinate and bacilli grow. Toxins damage the capillaries causing a severe necrotising myositis.  

A bacterial disease affecting cattle and sheep caused by [[Clostridium chauvoei|''Clostridium chauvoei'']]. Spores pass through the wall of the GI tract and via the bloodstream enter the muscle and liver where they then lie latent. This results in oedematous and crepitant swelling of the muscles. Under the correct conditions (usually anaerobic following injury) they germinate and bacilli grow. Toxins damage the capillaries causing a severe necrotising myositis.  

==History and Clinical Signs==

==History and Clinical Signs==

 

The bacteria can cause rapid toxaemia resulting in sudden death, however, if clinical signs do occur these can include toxaemia, pyrexia, depression, [[Pulmonary Oedema|pulmonary oedema]], circulatory collapse lameness and swollen hot muscles which later become cool as necrosis occurs.

The bacteria can cause rapid toxaemia resulting in sudden death, however, if clinical signs do occur these can include toxaemia, pyrexia, depression, [[Lungs Circulatory - Pathology#Pulmonary oedema|pulmonary oedema]], circulatory collapse lameness and swollen hot muscles which later become cool as necrosis occurs.

==Pathology==

==Pathology==

Affected muscle is black, dry, infiltrated with small bubbles, distended by serous or serosanguinous exudate and often has a rancid smell. The lesions can be present in any muscle including the tongue or diaphragm and it is not unusual to find clumps of gram positive bacteria in affected muscle. Often in sheep, lesions are deep and quite small. Suspected cases can be confirmed using demonstration of ''C. chauvoei'' in diseased muscle using the fluorescent antibody test on smears produced from the primary lesion.

Affected muscle is black, dry, infiltrated with small bubbles, distended by serous or serosanguinous exudate and often has a rancid smell. The lesions can be present in any muscle including the tongue or diaphragm and it is not unusual to find clumps of gram positive bacteria in affected muscle. Often in sheep, lesions are deep and quite small. Suspected cases can be confirmed using demonstration of ''C. chauvoei'' in diseased muscle using the fluorescent antibody test on smears produced from the primary lesion.

==Prognosis==

==Prognosis==

Poor, clinical cases can be treated with penicillin however this is rarely successful.

Poor, clinical cases can be treated with penicillin however this is rarely successful.

==References==

==References==

Merck & Co (2008) '''The Merck Veterinary Manual''' (Eighth Edition) Merial

Merck & Co (2008) '''The Merck Veterinary Manual''' (Eighth Edition) Merial

[[Category:Sheep]][[Category:Cattle]]

 

[[Category:To_Do_-_Caz]]

[[Category:To_Do_-_Review]]

[[Category:Musculoskeletal Diseases - Sheep]][[Category:Liver Diseases - Sheep]][[Category:Musculoskeletal Diseases - Cattle]][[Category:Liver Diseases - Cattle]][[Category:Bacterial Myositis]]

[[Category:Brian Aldridge reviewing]]