Canine Bilateral Extraocular Polymyositis

Abstract

This paper reports a bilateral polymyositis restricted to extraocular muscles, a pathologic change not previously reported in dogs. Two unrelated dogs manifested a distinctive syndrome of acute bilateral exophthalmos with extraocular myositis, confirmed either by surgical biopsy or by necropsy. One dog treated with corticosteroids showed a rapid resolution of clinical signs. The other dog was euthanatized and necropsied. The clinical and pathologic findings are reported for these two dogs and five other dogs with identical clinical signs and response to treatment with corticosteroids.