The disease usually commences in skeletal muscles but occasionally the heart or diaphragm is affected. The primary site of infection of black quarter was myocardium. The most commonly reported findings in classical blackleg are acute neutrophil necrotizing myositis that affects the skeletal muscle, and visceral myonecrosis, which is rarely diagnosed, but can affect the heart, sublingual muscles, and diaphragm.
Black quarter (BQ) is a predominant disease of cattle but traumatic black quarter may be seen in other animals.
Most cases of Black quarter occur during the warm months, or after soil excavation, or during very high annual rainfall that can expose and activate latent spores. In addition, the disease is enzootic in areas with a history of flooding.
Black quarter disease is caused by Clostridium chauvoei – a Gram-positive, rod shaped, sporeforming and toxin-producing anaerobe. The spores of the bacterium are very resistant to adverse environmental stress. There is no consensus on the pathogenesis of black quarter but toxins and neuraminidase produced by the causative bacteria are believed to play a significant role.
Black quarter disease
