# masticatory myositis



## Pointgold (Jun 6, 2007)

Because MMM is an immune-mediated disease, I would personally not breed a dog either diagnosed with it or who has produced it.


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## Abbydabbydo (Jan 31, 2007)

There is a really long thread about it over at TGRS, I guess it is pretty rare and not a lot of info about it.


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## GoldenJoyx'stwo (Feb 25, 2007)

Do you have a university library near you? If so, many universities have full-text access if you are using a campus computer to access the journals. You may also use a proxy in some cases. I have access and can use a proxy from home (many alumni can too), but you cannot always share the info online.

Abstract only: May have full access.
http://www.cababstractsplus.org/google/abstract.asp?AcNo=20043092225


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## Pointgold (Jun 6, 2007)

*Cut and paste from several sources*

*Myopathy, Focal Inflammatory--Masticatory Muscle Myositis and Extraocular Myositis
BASICS

DEFINITION 
Masticatory muscle myositis (MMM) is a focal inflammatory myopathy affecting the muscles of mastication (temporalis and masseter muscles) and sparing the limb muscles. Extraocular muscle myositis (EOM) selectively affects the extraocular muscles, sparing limb and masticatory muscles. 
Pathophysiology 
An immune-mediated etiology is suspected for MMM based on the presence of autoantibodies against type 2M fibers and a positive clinical response to immunosuppresive dosage of corticosteroids. An immune-mediated etiology is also suspected for EOM as a result of positive clinical response to corticosteroids. 
Systems Affected 
Neuromuscular--the muscles of mastication and extraocular muscles 
Genetics 
Unknown; however, as with autoimmune diseases in general, the appropriate genetic background must be present for the development of an autoimmune disease. 
• Golden retrievers may have a genetic predisposition to EOM. 
Incidence/Prevalence 
Unknown; however, MMM is not rare 
Geographic Distribution 
Probably worldwide 
Return to top
* 



*MASTICATORY MYOSITIS (Eosinophilic Myositis)* 

Masticatory muscle myositis (MMM) is the second most common neuromuscular disorder occurring in the dog.(the most common is Myasthenia Gravis). Several large and small breeds of dogs may be affected. As with MG, an early and accurate diagnosis is important for a favorable clinical outcome. Clinical signs include muscle atrophy and/or swelling restricted to the muscles of mastication, jaw pain, exophthalmos in the acute stage and enophthalmos in the chronic stage with marked muscle atrophy, and abnormalities of jaw movement including trismus or in rare cases inability to close the jaw. *Inability to open the jaws under anesthesia is a classical finding in MMM. *

*What are masticatory muscle myositis and extraocular myositis?* 

Myositis is the medical term for inflammation of the muscles. Masticatory muscle myositis (MMM) is an inflammatory disease that affects the muscles of the jaw. "Masticatory" refers to chewing. Extraocular myositis (EOM) is an inflammatory disease that selectively affects the muscles that surround the eye. Extraocular myositis does not affect the muscles of the jaw. Neither type of muscle inflammation affects the muscles of the limbs. Masticatory muscle myositis and extraocular myositis are seen in dogs. Golden retrievers may be more likely to develop extraocular myositis than other breeds. 
*What causes masticatory muscle myositis and extraocular myositis?* Masticatory muscle myositis and extraocular myositis are considered immune-mediated diseases. An immune-mediated disease is a malfunction of the body's immune defense mechanism in which the immune system is turned against the body rather than its normal function of protecting the body. The immune system actually attacks part of the body, in this case, the muscles.


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## GoldenJoyx'stwo (Feb 25, 2007)

I remember a member, not sure if they post here, whose dog had Myasthenia Gravis.


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## arcane (Sep 18, 2007)

thanks PG for that info...I think I found most of the information in my searches.


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## GoldenJoyx'stwo (Feb 25, 2007)

This dog hasn't been on any antimicrobials has it?


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