Idiopathic cholesterol pericarditis in a dog presenting with cardiac tamponade.

A 7-year, 6-month-old, female neutered, Pug dog presented with lethargy, hyporexia, polydipsia, abdominal distension, and dyspnea. Point-of-care ultrasonography identified tricavitary effusions and cardiac tamponade. Pericardiocentesis yielded 83 mL of sanguineous scintillating fluid. Clinical examination, bloodwork, echocardiography, electrocardiography, thoracic and abdominal computed tomography scans, and pericardial fluid analysis including culture and sensitivity did not identify any cardiovascular, endocrine, neoplastic, or infectious causes of the pericardial effusion. Pericardial fluid analysis identified high cholesterol concentrations and numerous cholesterol crystals on cytology, supporting a diagnosis of cholesterol pericarditis. Subtotal pericardiectomy was performed 7 weeks later to address pericardial and pleural effusions. Histopathological pericardial biopsies identified pericarditis with no neoplastic tissue detected. A pleural port was placed 4 months later to manage recurrent pleural effusion. Elective euthanasia was performed 10 weeks later citing a compromised quality of life from increasingly frequent bouts of dyspnea. This is a case report of a dog with idiopathic cholesterol pericarditis presenting with cardiac tamponade.