Is Mmm In Dogs Fatal

Masticatory myositis can be fatal as the dog cannot open its mouth to eat or drink properly. If the disease goes untreated or it has progressed to the point that most of the muscle fibers of the jaw have been replaced by fibrous tissue, this disease is not curable.

Who develops MMM? Are there some breeds that are more susceptible to MMM than others?

MMM can occur in any breed and in both males and females. The average age of MMM patients is 3 years, but there have been cases of dogs as young as 4 months with the disease. There are several breeds that are identified as more likely to develop MMM, These breeds include:

  • Golden Retrievers
  • Doberman Pinschers
  • German Shepherds
  • Labrador Retrievers
  • Cavalier King Charles Spaniels
  • Rottweilers
  • Weimaraners
  • Large Breed Dogs
  • How is MMM diagnosed?

    A dog’s inability to open his mouth, inability to eat, swollen chewing muscles, and excruciating face pain are symptoms of MMM. A blood test will diagnose MMM. The test searches for and measures circulating antibodies that attack the muscle fibers (autoantibodies). The blood test must be done before any treatment is provided, as treating with corticosteroid anti-inflammatory medication may cause the blood test to register a false negative.

    In cases where circulating autoantibodies are not detected, there is another diagnostic test for MMM, a muscle biopsy. The veterinarian removes a small section of affected muscle for evaluation. The muscle biopsy is used to determine the level of inflammation present as well as the severity of the fibrosis that occurs as the muscle tissue deteriorates.

    Q: What is the 2M antibody assay, and what is its sensitivity and specificity?

    The 2M antibody assay is an enzyme-linked immunosorbent assay (ELISA). Small plastic wells are coated with masticatory muscle myositis antigens, where serum from a dog suspected to suffer from MMM is placed on top.

    If the dog has any 2M antibodies present in the blood, these will attach to the antigens in the wells. Often a color-bonded enzyme will then be added to the solution to determine the presence of antibodies by displaying a color. The absorbance (intensity of the color) is then measured. A higher intensity meaning more antibodies present.

    Sensitivity or “true positive” (simplified) means how good the test is to determine whether a patient is carrying the disease. If sensitivity is very high – as it is with ELISA – the test will be very good at defining a true positive carrier of the disease as actually being positive.

    On the other hand, specificity is a measurement of how good a test determines that a patient does NOT have the disease. High specificity means that it is infrequent for an ELISA test to miss a positive. Conversely, if the test is negative, the patient is almost certainly not carrying the disease.


    How quickly does MMM progress in dogs?

    In the study, MMM generally carried a favorable prognosis when treated promptly with immunosuppressive doses of prednisone. Dogs typically regained normal masticatory function within 4 weeks of treatment, although 27% of affected dogs experienced relapse that resolved with continued glucocorticoid therapy.

    How do dogs get masticatory muscle myositis?

    Masticatory muscle myositis (MMM) is an immune system disorder in which the dog’s immune system identifies the dog’s own muscle tissue as foreign and attacks it. The masticatory muscles are the muscles involved with chewing. MMM causes these muscles to become swollen and painful.

    Is myositis in dogs painful?

    What causes masticatory myositis in dogs? Masticatory myositis in dogs is a result of an autoimmune targeting process in which autoantibodies (IgG) are produced and target the myofibers of the muscles of mastication. The underlying trigger of this immune response is unknown.