What is the causative agent of Blackleg?

What is the causative agent of Blackleg?

• A. Clostridium perfringens
• B. Clostridium chauvoei
• C. Bacillus anthracis
• D. Streptococcus suis

Answer: (B)

Blackleg is caused by Clostridium chauvoei, a spore-forming anaerobe that persists in soil for long periods. In susceptible cattle, especially after muscle injury or intense grazing, soil spores germinate in anaerobic damaged muscle. The bacteria then produce potent toxins that cause rapid myonecrosis and gas formation, leading to the sudden lameness, swelling, and crepitation characteristic of the disease. Vaccination with bacterin-toxoids is the main preventive measure. Other organisms listed are associated with different diseases or presentations (for example, Clostridium perfringens can cause gas gangrene in various contexts, Bacillus anthracis causes anthrax, and Streptococcus suis affects pigs), so they are not the typical cause of Blackleg.

Blackleg is caused by Clostridium chauvoei, a spore-forming anaerobe that persists in soil for long periods. In susceptible cattle, especially after muscle injury or intense grazing, soil spores germinate in anaerobic damaged muscle. The bacteria then produce potent toxins that cause rapid myonecrosis and gas formation, leading to the sudden lameness, swelling, and crepitation characteristic of the disease. Vaccination with bacterin-toxoids is the main preventive measure.

Other organisms listed are associated with different diseases or presentations (for example, Clostridium perfringens can cause gas gangrene in various contexts, Bacillus anthracis causes anthrax, and Streptococcus suis affects pigs), so they are not the typical cause of Blackleg.