masticatory myositis and GI issues

Re: masticatory myositis and GI issues

Andrew Kent — Mon, 22 Jul 2013 16:00:14 GMT

[quote user="Mark Lowrie"]

[quote user="Sarah Keir"]

Mark, would it be important to get gut biopsies before starting immunosuppressive drugs

[/quote]

Hi Sarah, I'm afraid gut biopsies are something I know little about and would have to refer you to someone with more knowledge in internal medicine to answer this. However, I can say that there is no reported link between MMM and IBD.

[/quote] Biopsies wouldn't be much use at this stage as response to antibiotics and response to diet have not been excluded meaning biopsies cannot be interpreted according to WSAVA guidelines.

Re: masticatory myositis and GI issues

Mark Lowrie — Mon, 22 Jul 2013 14:57:30 GMT

[quote user="Sarah Keir"]

Mark, would it be important to get gut biopsies before starting immunosuppressive drugs

[/quote]

Re: masticatory myositis and GI issues

Sarah Keir — Sat, 20 Jul 2013 19:22:05 GMT

Just my little thoughts, seeing as I am reading my notes on immune-mediated disease today...

It is possible both are immune-mediated diseases, IF the diarrhoea is being caused by inflammatory bowel disease. So perhaps this dog have a genetic tendency to immune-mediated disease? I can't find in my certificate notes any mention of a specific link between GI disease and masticatory myositis but I haven't done a publication search. Someone else may be able to answer this better. But the IBD is not an auto-immune disease (but MM is) so lupus is not likely.

Mark, would it be important to get gut biopsies before starting immunosuppressive drugs or just monitor the effect with regards to the diarrhoea rather than delaying treating the MM? Do you allow a 'wash-out' period after NSAID (eg 24h) before starting steroids or just monitor for GI bleeding or use GI protectants?

Cheers,

Sarah

Re: masticatory myositis and GI issues

Mark Lowrie — Fri, 19 Jul 2013 14:22:26 GMT

In which case I definitely would start pred at immunosuppressive doses tapering down over approx 4 months. The presence of inflammatory cells suggests on-going inflammation and hence pred is indicated if MMM is suspected. I wonder if the NSAIDs have done just enough to keep this at bay. It does also wax and wane and so the dog may just be in a period of disease quiescence.

The swollen eye could be an exophthalmos which is seen in the acute stages of MMM due to swelling of the pterygoid muscle.

Re: masticatory myositis and GI issues

james herriot lied — Fri, 19 Jul 2013 14:09:55 GMT

Sorry, Mark - there was mention of inflammatory changes, as mild inflammation at the margins of the fibrosis. But I am seriously wondering about MMM, as the dog does seem genuinely better on NSAIDs and time; one of the complicating factors was that one eye came up a bit puffy, and there was some talk of an orbital inflammation at the same time. Fortunately that has since recovered spontaneously, and was more likely to be traumatic.

We took bloods for MM Ab today and will hang on a week or two before instituting any pred therapy - should give us enough time to assess initial recovery.

But am I right in thinking that there's no 'Herriot's Syndrome' or the like, which links GI issues to a MMM?

Re: masticatory myositis and GI issues

Mark Lowrie — Fri, 19 Jul 2013 10:59:09 GMT

The muscle biopsy result doesn’t seem to mention any inflammatory change. Fibrosis corresponding to muscle fibre degeneration is very non-specific and is seen widely in normal muscle samples - it is also a fairly subjective measure. I would definitely medicate if I knew MMM was present but I would question this diagnosis a bit as I don’t think you’ve got good grounds to call this MMM. Do you have CK? However, if the dog is normal with no more problems I would probably do nothing more but doesn’t seem to fit with MMM to me.

Re: masticatory myositis and GI issues

Sarah Keir — Fri, 19 Jul 2013 09:56:32 GMT

Possible that both are auto-immune based diseases but don't jump to the conclusion that the diarrhoea related!