Testing for PSSM2

[Peregrine Falcon]

Negative for PSSM1 but suspect PSSM2. Those of you who have tested for type2 which did you perform? Biopsy, blood or hair?

 

[I'm Dun]

There is no reliable test. The hair/DNA test is flawed. Biopsy is the next best option but needs to be done when the horse is symptomatic or you can get a false negative. The hair test can be helpful as it can indicate which type of PSSM you are looking at, but you do need to be aware that horses can carry the gene and yet not have PSSM at all. There is also no defined treatment and the prognosis is very poor sadly.

Please dont just whack a high dose of vitamin e into them. That isnt the treatment for type 2 and wont rule in or out type 2 pssm.

 

[Peregrine Falcon]

Thanks for your reply. I am aware that the tests are not reliable nor some peer reviewed. I have already read that vit E is only for PSSM1. Trying to decide best course of action. ?

 

[Tiddlypom]

Why on earth not try an elevated dose of vit E? It works very well for some horses, inc mine, who is -ve for PSSM1 but was transformed by vit E.

The worst that will happen is that the horse does not improve.

I believe that that the only current definitive diagnosis for PSSM2 is by muscle biopsy after a -ve test for PSSM1, but false -ves are possible.

 

[paddy555]

Thanks for your reply. I am aware that the tests are not reliable nor some peer reviewed. I have already read that vit E is only for PSSM1. Trying to decide best course of action. ?

why wouldn't you give vit E? Mine was neg for PSSM1 and vit E transformed his life within days.

 

[Peregrine Falcon]

Already tried vit E prior to testing for type 1.

 

[Tiddlypom]

That's fair enough, SF. Sorry it didn't work for yours.

 

[Peregrine Falcon]

Thank you for the suggestion TP. Struggling to know where to go next. Still missing my old boy who was PTS in September which probably isn't helping.

 

[quizzie]

Already tried vit E prior to testing for type 1.

I have horse who has tested negative for both forms of PSSM, but who has all the characteristics of type 2, who I strongly suspect is affected by MFM. He showed no response to any form of vitamin E until I tried Nano-E, plus high amino/acids and moderate starch, and not much oil.
He now has a topline, is much happier and more forward in his work, and finally his vit E blood level is in normal range.
He never has had raised CK or AST.

 

[quizzie]

There is no reliable test. The hair/DNA test is flawed. Biopsy is the next best option but needs to be done when the horse is symptomatic or you can get a false negative. The hair test can be helpful as it can indicate which type of PSSM you are looking at, but you do need to be aware that horses can carry the gene and yet not have PSSM at all. There is also no defined treatment and the prognosis is very poor sadly.

Please dont just whack a high dose of vitamin e into them. That isnt the treatment for type 2 and wont rule in or out type 2 pssm.

This is not entirely true....PSSM2 is often used as a coverall diagnosis for any muscle myopathy that is not PSSM1. Some of the known ( and probably unknown ) myopathies DO respond to Vit E, eg MFM ( myofibrillar myositis)

 

[Peregrine Falcon]

I've got animo acids from Progressive Earth on order to see if that helps. Bloods run recently didn't bring up anything significant, lymes test showed exposure at some point but no current infection.

 

[quizzie]

I've got animo acids from Progressive Earth on order to see if that helps. Bloods run recently didn't bring up anything significant, lymes test showed exposure at some point but no current infection.

Did bloods include Vit E and selenium levels? Mine tested very low for Vit E initially, .....no change on even 10,000 iu natural powdered vit E.....started to rise with a month of starting Nano E.....I know it is hideously expensive, but there are some horses who cannot absorb or utilize the powdered forms of vit E which have an acetate ester attached (proven not anecdotal), so I would never rule out a diagnoses via lack of response to vitamin E before trying the water based form of Vit E.

 

[Peregrine Falcon]

@ quizzie not this time round-no. Have done previously and levels were normal.

 

[SEL]

I've got animo acids from Progressive Earth on order to see if that helps. Bloods run recently didn't bring up anything significant, lymes test showed exposure at some point but no current infection.

Lyme is interesting because it hides in the body and blood tests can give false negatives. I know Equinatural are now doing a herbal mix to help Lyme horses boost their immune system which might be worth a shot to see if it helps.

I do think biopsies can show if there is an underlying problem - there are a few cases on the PSSM forums of problems similar to EPM showing up in the UK which medication is needed to clear. Obviously they are intrusive though which is why so many people go down the Equiseq route. I know 3 people who've done those tests after odd results with blood tests. 2 came back with various PSSM 2 variants. The other was clear across the board.

 

[quizzie]

@ quizzie not this time round-no. Have done previously and levels were normal.

Might just be worth checking again?....and also have you got the actual level when you did test?, as some of them need rather higher than "just" in normal range?

It is often a combination of factors that provide the optimum management!

 

[Peregrine Falcon]

Quizzie, I would have to go back and check. Appreciate all your help.

SEL, there were 3 separate variants results to the lymes, I think they were acute/chronic and ? We've had 2 other ponies with it at the fields and they displayed slightly different symptoms. She's not displaying anything like them but we have an abundance of deer here!

 

[I'm Dun]

This is not entirely true....PSSM2 is often used as a coverall diagnosis for any muscle myopathy that is not PSSM1. Some of the known ( and probably unknown ) myopathies DO respond to Vit E, eg MFM ( myofibrillar myositis)

Yup, but a high dose of vitamin e wont work for most type 2s and isnt a good place to start. It should never be used as a diagnostic tool for type 2.

 

[Errin Paddywack]

Speaking personally I would try the hair test route. It may not be peer reviewed yet but hopefully it will give you a better idea of what is going on with your horse. If it all comes back negative then you will know to look elsewhere.

 

[paddy555]

Yup, but a high dose of vitamin e wont work for most type 2s and isnt a good place to start. It should never be used as a diagnostic tool for type 2.

question is though without a test (which there doesn't appear to be a satisfactory one) how do you know it is type 2. What diagnostic tools would you use? I don't understand your reasoning that vit e isn't a good place to start. Can you explain why please.

 

[quizzie]

Yup, but a high dose of vitamin e wont work for most type 2s and isnt a good place to start. It should never be used as a diagnostic tool for type 2.

But as we both know there is no fully accurate diagnostic tool for muscle myopathies apart from PSSM1.

So if suspecting a muscle myopathy which may or may not come under the current very loose definition of PSSM2, why would you not try vitamin E as part of your therapeutic regime...some may respond, some may not, but it is impossible to know which without trial and error in many of these cases. There are many other management and dietary components to the care of muscle myopathies, and maybe vitamin E gets too much prominence in discussion, but if I had a suspected case ( based on clinical signs, and full lab tests, but without genetic testing or muscle biopsy) in front of me , I would never say don't use vitamin E, it may not work....but I would advise a trial with and without the other components.

To be clear, when I am talking about a trial of vitamin E, I would always recommend the Nano E initially, as this has by far the greatest clinical effect in more horses, both from personal experience, and in peer reviewed papers.

 

[planete]

Regarding testing selenium level, according to my vet it is extremely tricky to obtain a reliable result, she did not recommend doing it.

 

[quizzie]

Regarding testing selenium level, according to my vet it is extremely tricky to obtain a reliable result, she did not recommend doing it.

I think the selenium is fairly accurate at most labs, but the vitamin E sample has to be very carefully handled ( frozen within a short period of sampling, and not delayed in post to specialist lab!).

I know it is a cost, but a few samples over a period of time will soon show if there is a pattern.

 

[planete]

I think the selenium is fairly accurate at most labs, but the vitamin E sample has to be very carefully handled ( frozen within a short period of sampling, and not delayed in post to specialist lab!).

I know it is a cost, but a few samples over a period of time will soon show if there is a pattern.

Apparently the problem is getting it to the lab without deterioration in the sample.

 

[quizzie]

Apparently the problem is getting it to the lab without deterioration in the sample.

Yup..that's the vit E test.

ETA : re the selenium test, my comments are true if the lab are using the GSH-Px test as an indicator of selenium levels, it may not be the case if they are still using the older test of selenium itself.

 

[SEL]

Quizzie, I would have to go back and check. Appreciate all your help.

SEL, there were 3 separate variants results to the lymes, I think they were acute/chronic and ? We've had 2 other ponies with it at the fields and they displayed slightly different symptoms. She's not displaying anything like them but we have an abundance of deer here!

Back when the PSSM forums were really only US based Lymes was always mentioned as a possibility if a horse was showing myopathy symptoms but negative for P1. The UK based people would confidently say we don't have it here - except we now know we do and it's popping up in humans often enough to make you think it's a lot more common.

I had a bit of a debate with my own vet a few years ago about whether my mare's issues could be Lyme - but given she's P1 I think I was clutching at straws. The vet did say that if Lyme was in the area then she'd consider speculatively treating for it. I'm just throwing it out there because if you're seeing symptoms that are possible PSSM then you're seeing symptoms that are possible Lyme too - & chronic Lyme is hard to detect.

You're also seeing symptoms that can relate to vitamin E deficiencies and selenium deficiencies so personally I'd supplement both unless you're in an area with high soil selenium. Most of the UK is deficient. Iodine is the other deficiency that can lead to muscle stiffness.

 

[quizzie]

Iodine is the other deficiency that can lead to muscle stiffness.

The problem with iodine is that as far as I know there is not a reliable blood test for it which indicates a tissue level deficiency, certainly in humans that is an issue.

Also looking at the soil iodine maps, it would appear that it is very localised...for instance where I live, the level is shown as varying from very low to very high within 1 mile, and lots of tiny pockets like that. So unless you know where all your grazing/forage and feed is situated/from, deciding whether and how much to supplement might be a bit of an issue and possibly unwise!

 

[catembi]

To answer the original question, I have done the hair test x 4. All the horses concerned were symptomatic beforehand. Horse 1: n/p1, n/p3, px/px, horse 2 - n/p4, horse 3: n/p4, px/px, horse 4: px/px. The results were consistent in that they corresponded to the symptoms that I was seeing.