A 4-year-old female spayed Miniature Poodle was presented to her primary care veterinarian for lethargy, weight loss and respiratory distress. Thoracic radiographs showed a moderate amount of pleural effusion. A thoracocentesis yielded over half a liter of fluid from the pleural space. The patient was treated with increasing doses of prednisone over a 10-month period without resolution of clinical signs. Serial thoracocenteses were performed every 2 to 4 weeks as needed. Cytologic evaluation of the effusion revealed a high protein transudate with reactive lymphoid cells. The patient was referred for the persisting pleural effusion. Physical examination at presentation revealed decreased lung sounds in the right ventral lung fields. A computed tomography scan revealed no significant abnormalities. It was concluded that the pleural effusion is likely idiopathic in nature. PleuralPort™ placement was achieved in the right lateral thorax and an additional 600mL of transudate were withdrawn from the pleural cavity post operatively.