Septic pericarditis caused by a migrating grass awn in a cat

Septic pericarditis and cardiac tamponade associated with migrating grass awn foreign bodies is reported rarely in companion animals. We report such a case in a previously healthy, 9-year-old, neutered female, indoor-outdoor, domestic long-hair cat who presented for acute tachypnea. Large volume pericardial effusion and pericardial tamponade was identified by thoracic-focused assessment with sonography. Following removal of 108 mL of purulent pericardial effusion by pericardiocentesis, the cat improved. Cytologic examination of pericardial fluid demonstrated septic, suppurative inflammation, Pasteurella sp. was cultured from pericardial effusion, and antibiotics were administered. Subsequent echocardiographic examination revealed large volume pericardial effusion, pericardial thickening, and a linear foreign body within the pericardial space. Whole-body computed tomography confirmed pericardial thickening, pericardial, and pleural effusion. A 16-mm long grass awn was identified within the pericardial space during thoracic exploratory surgery performed through a median sternotomy. Successful foreign body removal and subtotal pericardiectomy was accomplished. Histopathology of pericardial tissue disclosed chronic pericarditis with lymphoplasmacytic-to-pyogranulomatous inflammation, and transmural presence of grass awn foreign body. The cat responded to supportive therapy and was discharged 4 days postoperatively. When examined 3 weeks later, the cat appeared healthy with normal appetite. The cat remained healthy as of this writing, 487 days following surgery. To the author's knowledge, this is the first report in the cat of septic pericarditis and cardiac tamponade resulting from a migrating grass awn foreign body.