The anti-2M antibody titer is used to diagnose which disease in dogs?

The anti-2M antibody titer is used to diagnose which disease in dogs?

• A. Hip dysplasia
• B. CrCL disease
• C. Masticatory muscle myositis
• D. Hypothyroidism

Answer: (C)

The anti-2M antibody titer detects antibodies against the 2M myosin heavy chain in jaw muscles, which is the target of the autoimmune process in masticatory muscle myositis. When dogs develop MMM, the immune system attacks these masticatory muscles (notably the temporalis and masseter), causing inflammation, swelling, and progressive atrophy that leads to difficulty opening the mouth and pain. A positive anti-2M antibody test supports the diagnosis because these antibodies are strongly associated with MMM and are not a typical feature of hip dysplasia, cruciate ligament disease, or hypothyroidism. Those other conditions are diagnosed through joint imaging and orthopedic assessments, or endocrine testing, rather than this antibody test.

The anti-2M antibody titer detects antibodies against the 2M myosin heavy chain in jaw muscles, which is the target of the autoimmune process in masticatory muscle myositis. When dogs develop MMM, the immune system attacks these masticatory muscles (notably the temporalis and masseter), causing inflammation, swelling, and progressive atrophy that leads to difficulty opening the mouth and pain. A positive anti-2M antibody test supports the diagnosis because these antibodies are strongly associated with MMM and are not a typical feature of hip dysplasia, cruciate ligament disease, or hypothyroidism. Those other conditions are diagnosed through joint imaging and orthopedic assessments, or endocrine testing, rather than this antibody test.