Polymyositis following Vogt-Koyanagi-Harada-like syndrome in a Jack Russell terrier

A male Jack Russell terrier developed bilateral uveitis and glaucoma at 1 year of age. Since the ocular disease was painful and unresponsive to treatment, both globes were enucleated. Microscopical evaluation of one enucleated globe revealed panuveitis, with pigment dispersion and phagocytosis consistent with the ocular lesions of canine Vogt-Koyanagi-Harada (VKH)-like syndrome. Three years later the dog was represented with severe muscle disease and skin lesions. Due to rapid clinical deterioration the dog was humanely destroyed. Necropsy examination revealed lichenoid interface inflammation in the skin and mucous membranes, with pigmentary incontinence consistent with VKH-like syndrome and lymphocytic and histiocytic polymyositis with marked muscle atrophy. Canine VKH-like syndrome is an autoimmune disease that targets melanocyte antigens. Some human patients with VKH disease develop additional autoimmune diseases. To our knowledge this is the first reported case of polymyositis subsequent to VKH-like disease in a dog. In addition, VKH-like disease has not been previously reported in a Jack Russell terrier.