CHYLOTHORAX ASSOCIATED WITH CONSTRICTIVE PERICARDITIS IN A DOG

Chylothorax was associated with constrictive pericarditis in a 6-year- old mixed-breed dog. Clinical signs included hepatomegaly, bilateral j ugular pulses, muffled heart sounds, and dyspnea. Pleural effusion was identified on thoracic radiographs. Thoracentesis yielded 3 L of chyl ous effusion, confirmed by the cholesterol/triglyceride ratio (0.14). Echocardiography revealed a thickened pericardium, with numerous fibri n tags, which was suggestive of constrictive pericarditis. Central ven ous, right atrial, and right ventricular pressures were high and on ri ght ventricular diastolic pressure tracings, the square-root sign, whi ch is indicative of constrictive pericarditis, was evident. Explorator y thoracotomy and pericardiectomy were performed. Histopathologic find ings were consistent with chronic nonsuppurative pericarditis. The dog 's condition improved after surgery. On reevaluation 11 months later, central venous pressure and results of physical examination and thorac ic radiography were normal. On the basis of these findings, we conclud ed that chylothorax was caused by constrictive pericarditis in this do g. Chylothorax is often associated with disorders that have a poor pro gnosis, but if constrictive pericarditis can be identified as the caus e of the chylothorax, exploratory thoracotomy and pericardiectomy can provide a cure.