Blackleg is an acute, fatal disease that has been afflicting cattle since the late 1800’s. It is caused by the anaerobic, spore-forming bacteria Clostridium chauvoei. This disease is characterized by swelling in areas like the legs, hips, chest, and back, and is caused by toxins released from C. chauvoei that turn the surrounding tissue black or red and give this disease its name. This study surveyed cattle veterinarians in South Dakota to determine the incidence of blackleg in South Dakota. The goal was to determine the incidence in South Dakota and discover any specific regions that were more susceptible to blackleg. After administering this survey to a number of veterinarians, we found the herd-level incidence in South Dakota over the past 45 years to be 18%, and the overall incidence to be 2.82 cases per 100,000 head. The counties in South Dakota that had the highest herd-level blackleg incidence rates were Lawrence, Douglas, and Davison counties. The low herd-level and overall incidence rates in South Dakota are consistent with common perceptions and indicate current preventative measures are effective. Regional differences may be explained by a few factors such as recent soil disturbance/excavation, rainfall patterns, and variation in vaccination practices through time
