Progressive ossifying myositis in a cat.

Progressive ossifying myositis was diagnosed in a 2-year-old female cat. Clinical signs consisted of cervical pruritus, a stiff gait involving the forelimbs, and decreased range of motion of the scapulohumeral joints. The signs progressed over a 2-month period to involve the hindlimbs and coxofemoral joints. The primary cause of this disease is unknown and treatment is palliative. Treatment with diphosphonate disodium etidronate was unsuccessful in controlling the clinical signs in this case.