By Andi Anderson
Blackleg is a severe and rapidly fatal disease that commonly affects calves between six and twelve months of age. It is caused by the bacterium Clostridium chauvoei and often leads to sudden death without visible warning signs. Calves in good nutritional condition are usually the most vulnerable, and the disease progresses quickly once toxins begin damaging muscle tissue in the hindquarters and heart.
Cattle typically become infected by ingesting spores from contaminated soil or water. These spores enter the bloodstream and settle in muscle tissue, where they may remain inactive for months or years. When muscle tissue is injured or deprived of oxygen, the spores can germinate, allowing the bacteria to grow and release toxins that cause fatal damage.
Affected calves may show early signs such as fever, swelling, and lameness, although these symptoms are often missed because death occurs within a day. Swollen areas may feel warm at first but soon become cold due to tissue death. Gas buildup beneath the skin can create a crackling sound, a typical feature of the disease.
Spores are present in soil, water, and the digestive tracts of many animals. They can survive harsh conditions for years, making blackleg unpredictable. Cases may appear unexpectedly on farms with no previous history, especially after heavy rainfall, flooding, or soil disturbance, which brings more spores to the surface.
Vaccination remains the most reliable protection against blackleg. A 7‑way or 8‑way clostridial vaccine is almost 100% effective when given according to label directions. Calves should receive a two‑dose series starting around three months of age, followed by an annual booster. Adult cattle also benefit from yearly boosters because spores can remain dormant in their bodies for long periods.
Combination vaccines, including those that protect against conditions such as pinkeye or enterotoxemia, are also available and effective when used properly. Farmers should check labels to ensure protection against Clostridium chauvoei, the cause of blackleg.
Overall, vaccination is inexpensive, safe, and essential for preventing this deadly disease. Working with a veterinarian can help farmers create a vaccination plan tailored to their herd’s specific needs.
Photo Credit: gettyimages-ahavelaar
Categories: Ohio, Livestock