Pericarditis and pleuritis caused by Corynebacterium pseudotuberculosis in a horse

A 13-year-old Oldenburg mare was evaluated for lethargy and signs of mild colic. Pericardial tamponade caused by fibrinoeffusive pericarditis was diagnosed. Cytologic and biochemical evaluation of pericardial fluid was consistent with a septic effusion. Corynebacterium pseudotuberculosis, the cause of pigeon fever, was identified by bacteriologic culture of pericardial fluid. Drainage and lavage of the pericardial sac, local (intrapericardial) and systemic antimicrobial treatment, and subsequent corticosteroid treatment resulted in a successful outcome in this horse. To the authors' knowledge, this is the first report of pericarditis associated with C pseudotuberculosis in a horse.