Canine Disease Information: Masticatory Muscle Myositis - eosinophilic myositis



  • Type Disease
    Musculoskeletal
  • Name
    Masticatory Muscle Myositis - eosinophilic myositis
  • Abbreviation
    MMMx
  • 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.
  • How Transferred
    Unknown.
  • What to Look for
    Many dogs affected with masticatory muscle myositis will improve with drug therapy.\n\n
  • Diagnosis
    Your veterinarian will suspect this disease if your dog has painful, swollen masticatory muscles, with pain on opening the jaw. The diagnosis can be confirmed with a muscle biopsy to examine the cells with a microscope. Special techniques may be used to test for specific antibodies.\n\n
  • Treatment
    Affected dogs are usually treated medically, with glucocorticoids such as prednisone. Most dogs improve with drug therapy, although the treatment may be long-term.
  • Breeding Considerations
    Affected animals should not be bred.\n
  • Known Breeds Affected
    German shepherd

Type Disease

Known Breeds Affected

Type Disease

Known Breeds Affected