Idiopathic pleural effusion in a dog.

Idiopathic pleural effusion was diagnosed in a 4-year-old female Poodle. Treatment included giving low doses of furosemide for 5 months and giving low doses of prednisone that eventually were given on alternate days and discontinued 16 months after initial evaluation. Idiopathic pleural effusion in this dog was eosinophilic. The clinical importance and diagnostic value of this finding were not determined. In man, idiopathic pleural effusions have a high correlation with eosinophilic pleural effusions.