Cat with short legs looking up.

Myositis and Myopathies

Myositis is inflammation of muscle tissue that results in pain, weakness, and muscle atrophy (shrinking). Cats suffering from severe bouts of myositis are reluctant to move and can actually appear as if they are paralyzed as a result of the inflammatory effects on the muscles.

Myositis can be caused by a number of different disease entities, including toxoplasmosis, leptospirosis, bacterial infections (abscesses), low blood potassium, and autoimmune disease.

Myositis is diagnosed using clinical signs and blood tests designed to detect increased levels in muscle enzymes within the blood. In especially elusive cases, biopsy samples taken from suspected muscle tissue can help veterinarians obtain a definitive diagnosis.

Treatment for myositis is aimed at the underlying cause. If infections are to blame, appropriate antimicrobial or antiparasitic therapy will help relieve the myositis.

Anti-inflammatory medications can also be used to relieve the pain and discomfort associated with the inflammation until the underlying cause is treated.

Autoimmune myositis, such as masticatory myositis, is treated with high levels of glucocorticosteroids (such as prednisolone) in an effort to suppress the immune response causing the inflammation in the first place.

The prognosis for complete recovery with autoimmune myositis is poor, yet with medications, the signs associated with the disorder can be kept under control.

The term myopathy refers to abnormal anatomy and/or function of skeletal muscle tissue within the body. Unfortunately, there is no effective treatment to stop the progression of these myopathies.