Answer to Dr. Broughton’s Mystery Photo- November 2021

The cause of death in this steer is Clostridium chauvoei infection resulting in a fibrinosuppurative pleuritis and epicarditis with no associated pneumonia. Clostridium chauvoei infection, also known as blackleg, most commonly occurs in rapidly growing cattle 9 months to 2 years of age and typically results in myonecrosis of large skeletal muscle bellies, such as the pectoral or pelvic muscles. In this case, the presentation of pleuritis and epicarditis is an uncommon but well documented form of blackleg in cattle.

Infection is more common in beef cattle but can occur in any breed as well as other species such as sheep, horses, and deer. Often, multiple animals in a group are affected in a short period of time and mortality rates approach 100%. Animals are frequently found dead with no clinical signs. Prevention of clostridial diseases is accomplished through vaccination, typically against multiple clostridial species at once.