Immune-Mediated Polymyositis in a Dog

Polymyositis is a noninfectious inflammatory disease of the striated muscle and is classified as a systemic immune-mediated disease. Human polymyositis is diagnosed through the following criteria: (1) the clinical signs like symmetrical proximal muscle weakness, (2) biochemical data (high concentrations of serum muscle enzymes), (3) abnormal electromyographic (EMG) findings and (4) histopathological diagnosis. However, there have been only a few reports on immune-mediated polymyositis in dogs. This paper reports a case of definite polymyositis of a dog which fulfils these 4 criteria.