What is blackleg?

• A bacterial disease affecting the skeletal and cardiac muscles caused by Clostridium chauvoei
• Animals often die within 12 to 48 hours

Cattle affected

• Occurs mostly in rapidly growing animals 6 months to 2 years of age, but other ages can be affected
• Animals are often in excellent body condition and on a high plane of nutrition

Disease development

• Blackleg doesn’t pass from animal to animal; cattle become infected from eating spores in soil
• Spores can exist in the animal’s bloodstream and muscles without causing disease
• Usually, some kind of muscle trauma enables the spores to grow and release toxins, causing local tissue death

Signs

• Lameness, depression, anorexia, fever
• Swellings can develop at various body locations

Diagnosis

• Presumptive diagnosis made based on signs and visible lesions
• Confirmation by tissue testing
• Affected muscles are dark red or black with a rancid odor

Treatment

• Because animals typically die quickly, there’s often no time for treatment
• If there is time, penicillin G procaine and supportive care (anti-inflammatory drugs, fluids) may help

Disposal

• Animals that die from blackleg can seed the environment with spores, increasing risk for future outbreaks
• Carcasses should be burned or buried in deep ground

Prevention

• Vaccinate cattle under 2 years of age
• Vaccinate cows in late gestation to help generate antibodies in colostrum