Masseter Myositis (autoimmune disease)

[TPO]

Does anyone have any knowledge or experience of this?

Incredibly rare, as far as I can gather. The majority of "hindsight" papers are American. I don't have pub med/Google scholar to access everything that I can find online.

TIA

 

[gunnergundog]

My only experience of it is in a dog so unsure if relevant. Unfortunately, it was not a good outcome. The bitch also had another issue (DISH) and the medication for that was not compatible with the steroids required for MMM. So, we could manage the DISH and she couldn't eat, or we could manage the MMM and she could eat but then had extreme back pain. She did respond well to the steroids though.

Don't you just hate it, when.......

.....the vet examining your dog (or horse/cat/whatever) goes: 'Oooooo..............now this is REALLY interesting'. Alarm bells and pound signs flash immediately in front of my eyes. Masticatory muscle myositis (MMM) anyone?

forums.horseandhound.co.uk

 

[stangs]

No experience of it unfortunately but I have access to a lot of journals (though not all the American veterinary ones) - if you let me know which papers you’d like to read, I can try send you information from them.

 

[TPO]

Thanks. The vet said that it's more common in dogs, particularly west Highland terriers.

High dose of Steroids are the only treatment for horses too. Due to a myriad of other disasters there's a chance he's developed ulcers so need to scope, and treat if required, for them first as the steroids would affect them.

Waiting for blood test results and equine dental specialist vet is out for the third time on Wednesday to check him.

This all started because I've dutifully used a fully qualified EDT very regularly and they've missed something major for years. Another turn of events led to me using new vet for teeth who found the painful and serious issue. Referred to dental specialist vet for a procedure, and we've gone rapidly downhill ever since.

EDT did teeth Oct 22 but I had vet look April 23 as I wasn't happy with his condition and how little he appeared to be eating. A very painful mouth explained that but since that's been "fixed" ot appears to have created a whole other problem or ten.

Sorry to hear about your dog.

 

[TPO]

No experience of it unfortunately but I have access to a lot of journals (though not all the American veterinary ones) - if you let me know which papers you’d like to read, I can try send you information from them.

Thanks, will PM you

 

[palo1]

No knowledge of this I am afraid and I am really sorry to hear you are having to deal with it; I can imagine how godawful and stressful it is. Hopefully vet and steroid treatment will see a good result.

 

[Reacher]

Oh no really sorry to hear his teeth have got worse, poor lad hope your dentist vet gets to the bottom of it.

 

[BronsonNutter]

Please let us know how you get on; it's very uncommon! Keeping my fingers crossed that he responds well to treatment.

Interestingly, re the potential ulcers, some medicine specialists are not overly worried about a horse being on steroids alongside ulcer treatment - so may not be as much of an issue as feared. And I guess if he can eat forage more comfortably that would help from an ulcer prevention perspective.

 

[Tiddlypom]

Oh heck, TPO, I haven't heard of this but I wish you and your chap all the best.

Like you, I've been dealing with dental issues not picked up despite regular floating by a qualified EDT. We owners can only do our best re trying to get good people on the job.

It's much easier for an owner to spot poor foot care than less than optimal dentistry.

 

[Landcruiser]

Well I have been doing a lot of reading about Selenium deficiency as my mare has just been found to have less than half the level that she should have. OP, degeneration of the masticatory muscles is known to be as a result of Selenium deficiency, has your vet tested the level in your horse? I was alerted to ask because my girl had elevated CK (muscle enzyme) when she had full bloods done, which persisted to the next test a month later. I then asked them to test for selenium as this has a known correlation with elevated muscle enzymes. Also with damage to the immune system.

 

[Landcruiser]

Muscle: masseter myodegeneration / myositis in Horses (Equis) | Vetlexicon

View Muscle: masseter myodegeneration / myositis & more Equis resources at Vetlexicon. Over 28,000 peer-reviewed resources: Canis, Bovis, Felis, Lapis & Exotis.

www.vetlexicon.com

Not the full article (paywall) but a good intro

 

[TPO]

Thanks @Landcruiser

I'll hear back about bloods this afternoon at the earliest or tomorrow afternoon at the latest. I'll ask about selenium deficiency and further testing then. I’ve been reading similar material and have ordered a natural vit E & selenium supplement that should arrive today.

Thanks to a suggestion by the wonderful Milliepops Chip is now eating. Saracen Re-Leve is indeed horse crack!

He is getting small feeds regularly and inhaling them. This seems to have kicked started his system as he is now grazing more and did a whole 3 poos overnight 4 if you include the one while handgrazing and he actually ate for a whole half hour of handgrazing last night.

I don't think that he has pain in his masseter and I haven't seen any evidence of opening his mouth being uncomfortable. However the muscle wastage is very apparent everywhere else.

The dental specialist vet is out tomorrow afternoon so I'll hopefully know more after that and the bloods.

 

[Landcruiser]

Best not supplement selenium until you know for sure though. I found the recommended levels vary wildly - from 1mg or 1.25mg a day widely in the UK, to up to 6mg on some websites when giving for a known deficiency. My "good all round vitamin and mineral supplement" turns out to only give .3mg. I am currently giving 2mg but may increase to 3 once I've spoken to Simon Hatch at Trinity Consultants (he's on hol this wk).
The lab were able to do the selenium as an add on using the bloods they already had for the repeat CK test, so it's probably worth asking your vet to request it now.

 

[Reacher]

I wasn’t going to post in case not relevant (and you’ve probably already read it) but if it is the same disease you can read the whole article . It talks about vit. e and selenium too

https://beva.onlinelibrary.wiley.com/doi/full/10.1111/eve.13737

 

[TPO]

Thanks.

I'm not a vet but I don't think Chip has presented like MM other than muscle wastage along his spine and quarters. Its very extreme even for his lack of food.

He is opening his mouth fine and since having forage reintroduced (was initially withheld as a contradiction to dental procedure aftercare. It was Grass only at that point).

Will see what bloods reveal (although MM can't be diagnosed by bloods, this is just to discount other things) and what specialist thinks.

 

[TPO]

This was him 18 april after vet visit but before the dental procedure.





No grass left in winter field but adlib hay. I was worried about how light he was running. The camera does add weight because he looked lighter in the flesh.

Then 19 April coming to after the procedure





























 

[TPO]

Some of the swellings. It was cheek teeth were the issue but no real swelling in that area.

 

[TPO]

And finally, how he's looking now despite round the clock care, a plethora of feed options, grass (photo in bare field where there's adlib hay, adjoining paddock has grass), hand grazing and bute trials.































Fattest Cob (who gets less to eat than Chips been eating!) for contrast!

 

[Reacher]

Oh crikey TPO no wonder you are worried

 

[palo1]

I really hope the specialist is able to give a clear picture and advice for you. Selenium is a very tricky element and too much or too little can cause extraordinary problems so I hope that diet may be at least part of the answer.

 

[Tiddlypom]

Oh heck, poor lad and poor you, I didn't expect to see him looking like that .

Fingers firmly crossed that you can get to the bottom of it all and get him sorted.

 

[Midlifecrisis]

Wow TPO no wonder you are worried…sadly I have experience at all about this but wanted to send a hug to you and Chip.

 

[Ambers Echo]

So sorry, TPO. No advice but didn't want to read and run. Hope you get answes and solutions very soon xx

 

[scats]

Gosh, so sorry to see this TPO. I really hope you can get to the bottom of this.

 

[The Fuzzy Furry]

That is a considerable change, poor chap. Really hope you get something decisive that can be succesfully acted on from the bloods xx

 

[SEL]

I can see why you're worried. Were the swellings in his face from the missed teeth issue? And he's kept dropping since that was fixed?

I hope the bloods give you answers. Very much hoping for an easy fix xx

 

[TPO]

I can see why you're worried. Were the swellings in his face from the missed teeth issue? And he's kept dropping since that was fixed?

I hope the bloods give you answers. Very much hoping for an easy fix xx

No, no indication of the missed teeth issue apart from he wasn't eating much hay, in the field or overnight, or finishing his feeds. He'd dropped a bit of weight so, despite doing teeth with edt in Oct, decided to get vet to check while she was out doing mums horses (one of them had a tooth removed ans this was 6mth check up).

I honestly didn't expect it to be teeth because he's always had a clean bill of health but was starting there with his MOT.

The issues were up with cheek teeth and there hasn't really been swellings related to that area.

His saliva glands were massively, and unusually, up along with lymph nodes. The most extreme swelling was where a chin groove should be but at times his whole head was swollen.

Yes, he's only been this broken since he was "fixed". Specialist is adamant its nothing to do with the procedure, and logically it shouldn't be, but it's only been since then. Both vet and specialist had to come back out after the procedure because his recovery wasn't going well and now here we are...

 

[SEL]

His saliva glands were massively, and unusually, up along with lymph nodes. The most extreme swelling was where a chin groove should be but at times his whole head was swollen.

Yes, he's only been this broken since he was "fixed". Specialist is adamant its nothing to do with the procedure, and logically it shouldn't be, but it's only been since then. Both vet and specialist had to come back out after the procedure because his recovery wasn't going well and now here we are...

Saliva glands swelling after dental work - even head swelling - I can understand. I've heard of infections even after quite minor work. In fact Google has just told me about sialoliths so I've learnt something new. Has that all gone down now? But none of that would explain him not regaining weight once it was comfy to eat again.

Is he happy in himself?

 

[TPO]

Saliva glands swelling after dental work - even head swelling - I can understand. I've heard of infections even after quite minor work. In fact Google has just told me about sialoliths so I've learnt something new. Has that all gone down now? But none of that would explain him not regaining weight once it was comfy to eat again.

Is he happy in himself?

It went down last week for the first time.

He wasn't happy, he was really sad and withdrawn. He's perked up 100% since Monday and getting Releve/eating. He's much brighter and back to neighing for his dinner.

The specialist said the swelling that he had isn't what you'd expect from thr work he had done and ditto the saliva glands. He put the glands down to grass but it made no sense. He's hmhad glands a day or two when grass comes through but he's been on the same grazing for 5yrs now and the other two were on it too. That duration of swelling, nevr mind the size, is completely abnormal for him.

I don't think it's MM as he has never appeared to have pain in his masseter muscle or any bother opening his mouth. However he had lost all appetite and muscle wastage. It's all I've got to go on, and that's since April, so just trying to find out as much as I can to cover all bases.

Have never heard of sialoliths so away to google. Thanks!

Eta - you learn something new everyday. I'm pretty sure it's not that but that would have been a better explanation than what I've had so far!

 

[TPO]

After all this it isn't IMM.

Bloods show low protein and high white count. Typical for worm infestation but he's on a proper worming programme, all worming & counts are up to date and poo-picked fields etc. Running further bloods for encysted red.

If it isn't encysted red next step is ultrasound on stomach and belly tap.

Specialist is back out this afternoon to check his mouth so hopefully that gets the all clear and that's one thing off the list.

The fat head and extensive swelling is because of the low protein. I can't remember the proper names and terminology used because the signal wasn't great so bear with me. Basically with head being down grazing gravity pulls everything into it but a healthy system keeps everything moving. With this low protein the fluid isn't pulled away and builds up. It's unusual to have it just in the head; normally everywhere affected by gravity like stomach and sheath.

If his mouth checks out ok today and encysted red test is clear my inclination is to give him a couple of weeks to see if he picks up. He's started eating and is a lot more himself and bright. Saracen Horse Feeds have been a brilliant source of help and are sending out further samples to see if we can keep him eating and more fibre into him.

Anyway, that's it for now. Thanks for your help. I'm trying to avoid HHO but it's handy when the unusual pops up. Thanks for the replies on here, PMs and messages off HHO wishing Chip well.