Watch Out for the Threat of a Blackleg Outbreak

Learn how the weather can impact clostridial diseases and what you can do to keep your herd protected 


DULUTH, Ga. — From blizzards to torrential flooding, dramatic weather continues to challenge cattle producers. There are many things to worry about when the weather is bad, but there’s a threat that may not be top of mind — blackleg. 


“Blackleg can occur after flooding, and sometimes we’ve even seen outbreaks of blackleg after dirt work or excavating has been done on the farm,” remarked Daniel Cummings, DVM, Boehringer Ingelheim. “The clostridial spores will rise to the top of the soil, and then we get an increased risk of animals ingesting those infective spores.” Dr. Cummings noted that outbreaks can also occur after prolonged dry spells followed by heavy rainfall.


Figure 1. The graph above shows the path of clostridial spores, from the soil to infection of the animal.


Clinical signs of blackleg include fever, depression, tremoring or even loss of appetite. According to Dr. Cummings, these signs are difficult to identify and, oftentimes, are not observed within a herd. Many times, the first sign of disease is acute or sudden death of cattle.


“Most of the time, blackleg affects well-conditioned or well-nourished cattle ranging from ages 6 to 18 months,” commented Dr. Cummings.


Finding a successful treatment for blackleg is rare, so taking preventive measures is critical.3 “We rely heavily on prevention through vaccination, however, this year we haven’t vaccinated cattle as we normally would, according to the herd health calendar, due to weather challenges,” remarked Dr. Cummings. “I think this may be a contributing factor as to why we’re seeing an increase in blackleg cases.”


To protect against blackleg and other fatal clostridial diseases, Dr. Cummings recommends vaccinating with a single dose, seven-way clostridium vaccine. 


“The clostridium vaccines are very effective because they stimulate an adequate immune response to protect against blackleg,” stated Dr. Cummings. “Blackleg is one of the few diseases in cattle that can be prevented, quite well, with vaccination, because our vaccines are considered to be highly effective and safe.”


If a producer experiences, or suspects, blackleg disease in their herd triggered by factors that may include flooding, dirt excavation or extreme weather conditions, the first step should be contacting their veterinarian. Working with a veterinarian will help determine the most effective vaccine protocol to improve overall herd health.

Source: Boehringer Ingelheim