Septic pericarditis in a cat with pyometra

Objective To describe a unique cause of septic pericarditis in a cat and detail the successful case management strategy. Case summary A 6‐year‐old sexually intact female R agdoll cat was evaluated for a 7‐day history of progressive lethargy, anorexia, and vaginal discharge. Thoracic radiographs revealed a markedly globoid cardiac silhouette and pleural effusion while the initial echocardiogram showed moderate volume pericardial effusion. Following pericardiocentesis, cytologic evaluation of the pericardial effusion revealed septic suppurative inflammation with intra‐ and extracellular G ram‐negative rod‐shaped bacteria. Abdominal ultrasound demonstrated a moderate amount of echogenic uterine fluid accumulation with a right‐sided uterine horn mass. After stabilization with pericardiocentesis, IV fluid therapy and IV antimicrobials, the cat underwent ovariohysterectomy and partial pericardiectomy. Histopathology confirmed a diagnosis of pyometra and septic pericarditis. Uterine and pericardial fluid bacterial culture yielded E scherichia coli with identical antimicrobial sensitivity spectrums. New or unique information provided Septic pericarditis is a rare cause of pericardial effusion in the cat. Previous reported cases have either suggested the cause to be secondary to transient bacteremia resulting from a local infection seeding the pericardium or for the cause to remain unknown. To the authors’ knowledge, this is the first veterinary report of septic pericarditis resulting from hematogeneously spread bacteria originating from a urogenital infection. It is also the first report of successful surgical management of septic pericarditis in the cat.