Disease Description: This disease affects the masticatory muscles - the large muscles on the top and sides of the head which act to close the jaw. These muscles have a unique muscle protein composition. Masticatory muscle myositis is an immune-mediated disease in which the body’s immune system attacks the unique muscle protein found in the masticatory muscles. This causes the muscles to become painful and swollen initially, and the muscles will atrophy as the disease progresses. Opening the mouth is particularly painful.

Inherit Mode: Unknown.

Disease Symptom: Many dogs affected with masticatory muscle myositiswill improvewith drug therapy.

Disease Cause: -

Disease Diagnose: Your veterinarian will suspect this disease if yourdog has painful,swollen masticatory muscles, with pain on opening the jaw. Thediagnosis can be confirmedwith a muscle biopsy to examine the cells with a microscope. Specialtechniques may beused to test for specific antibodies.

Treat Method: Affected dogs are usually treated medically, withglucocorticoidssuch as prednisone. Most dogs improve with drug therapy, although thetreatment may belong-term.

Breeder Advice: Affected animals should not be bred.

Disease Description Source: Link