Talk to me about pssm2

[[153312]]

Having been doing some reading on pssm2 I'm wondering the pros and cons of a muscle biopsy versus just trialling vitamin e/pssm husbandry changes. I have suspected for a while my appaloosa may have it although she's negative for pssm1.
Any thoughts on one Vs the other?

 

[rextherobber]

I did diet changes while waiting for the results of the CAG hair test ( unvalidated ). I don't feel the need to do the muscle biopsy to confirm the results I got from CAG ( my vets disagree) There is an extremely good Facebook group (PSSM and MFM Awareness) which has been far more help in the management of my horse than my vet has. Mine is managed well on their advice. Good luck with your horse.

 

[Tiddlypom]

The muscle biopsy can give false negatives. I didn't bother getting it done as the horse had responded so well to vit E and being kept warm. Vet agreed, though if it had been her horse she'd have done the muscle biopsy for completeness.

Horse tested -ve for PSSM1 via the Animal Genetics hair test.

 

[[153312]]

Thank you both - I'll have a look at the FB group. I just think there's something missing about this horse, some symptoms which could be something, could be nothing, that might be explained by pssm2. She was retired two years ago after ulcer scoping, back X rays and lameness work ups found nothing to explain it, and I couldn't afford to send her to a vet hospital but wasn't prepared to just push her through it as a lot of people said I should as it was pretty obviously a pain response (the vets agreed on that too, we just don't know what it was being caused by!).
I did the pssm1 test and later an EMS test and I still feel I don't have a complete explanation. The mare's daughter is +ve for pssm1 and 2 as well, although the daughters breeder thinks it comes from the sire but I'm not wholly convinced.

 

[shortstuff99]

There are genetic tests for PSSM 2, but they haven't been peer reviewed yet. Also being clear for the current genes of PSSM 2 doesn't mean your horse doesn't have PSSM 2 but it can be a starting point.

 

[catembi]

I have done the hair test for type 2 with CAG twice and am about to do it a third time (different horses). I am in 2 or 3 PSSM support groups on FB. As I understand it, the muscle biopsy can give a false -ve firstly because sometimes there isn't enough damage to detect until the horse is older and secondly because it can affect different muscle groups.

The CAG test is completely non invasive and can give an answer to the question of, 'what on earth is wrong with my horse'.

 

[[153312]]

Is the genetic test you've done the equi seq one?

 

[rextherobber]

Is the genetic test you've done the equi seq one?

Equiseq for USA ,CAG for Europe

 

[rextherobber]

I have done the hair test for type 2 with CAG twice and am about to do it a third time (different horses). I am in 2 or 3 PSSM support groups on FB. As I understand it, the muscle biopsy can give a false -ve firstly because sometimes there isn't enough damage to detect until the horse is older and secondly because it can affect different muscle groups.

The CAG test is completely non invasive and can give an answer to the question of, 'what on earth is wrong with my horse'.

So sorry to hear you need to test another one Catembi.

 

[paddy555]

[/QUOTE]

The mare's daughter is +ve for pssm1 and 2 as well, although the daughters breeder thinks it comes from the sire but I'm not wholly convinced.

if you have details of both parents and preferably the pedigree then search Sharalee Worms on FB (she will be on the PSSM groups and comes up under FB search. Give details of the breeding and you may get some answers and it may tell you that you are on the right diagnostic track.

 

[[153312]]

I don't know any of her breeding. I say Appaloosa based on her colour/general phenotype only. Realistically she's just a heinz 57 who also happens to be fewspot (LPLPPATN1PATN1) so both sides of her breeding must have been spotbred.

 

[quizzie]

Have a look at this website which is mostly by the world authority on equine muscle myopathies, so gives info on both PSSM 1 & 2 and other related myopathies:

https://cvm.msu.edu/research/facult...ratory/type-2-polysaccharide-storage-myopathy

Another thought, if you are going to try Vit E as a "diagnostic" tool, I would strongly advise using Nano-E....there are some horses who do not absorb/utilise the powdered acetate forms of Vit E ( even the Natural version).

 

[Murphy88]

There is a recent peer-reviewed study by the foremost specialist in equine neuromuscular disease (Stephanie Valberg at the MSU Neuromuscular lab) showing that the commercial genetic tests (CAG/EquiSeq) are not accurate. The variants they are looking for are present in >25% of normal horses and are not predictive of either the presence or absence of PSSM2. The paper is open access on EVJ so available for anyone to read.
https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.13345

OP: Muscle biopsies are simple to perform and generally tolerated very well by the horse, and unfortunately they are currently the only definitive way to diagnose PSSM2. But there is also no harm in trialling the vitamin E and husbandry changes and seeing if you have a response. I would echo the above poster though and say make sure to use a natural rather than synthetic vitamin E, and liquid formulations are best.

 

[bluehorse]

Try the husbandry changes first, it can’t hurt and might tell you all you need to know. I did this for my suspected pssm2 warmblood. I started following the recommendations made by Valberg for the MFM variant which is found in Warmbloods. I’m supplementing high levels of quality protein and amino acids, the rest of his diet was already as recommended so no other changes apart from that. The difference is astonishing, he has energy, his muscles are slowly getting stronger and I have a horse to ride again instead of something that felt like he could barely put one foot in front of the other. He struggled to make it round a 40minute hack. He is not perfect, he’ll never be completely ’right’ but I feel he can cope with his work. Adding the protein has made a bigger difference than the three Bute trials I’ve done over the last couple of years when I’d put him on 4 a day with no change. I won’t bother with the CAG test, if he does have it, it doesn’t make any difference as I’m already following the protocol and there is no other treatment. If he doesn’t have it, he obviously needed a bit of a diet change and that’s all. But I suspect the former. Knowing makes no difference to me or him.

 

[I'm Dun]

vitamin e in whatever dose or form will not give you any information about type 2 PSSM. Its not the recommended treatment, although some do find it helps

 

[quizzie]

vitamin e in whatever dose or form will not give you any information about type 2 PSSM. Its not the recommended treatment, although some do find it helps

Not for “classic” PSSM 2, but it is for various other (often difficult to diagnose) myopathies that often get lumped under the same heading eg: MFM or vitamin E responsive neuromyopathies, so well worth trying.

 

[DabDab]

Try the husbandry changes first, it can’t hurt and might tell you all you need to know. I did this for my suspected pssm2 warmblood. I started following the recommendations made by Valberg for the MFM variant which is found in Warmbloods. I’m supplementing high levels of quality protein and amino acids, the rest of his diet was already as recommended so no other changes apart from that. The difference is astonishing, he has energy, his muscles are slowly getting stronger and I have a horse to ride again instead of something that felt like he could barely put one foot in front of the other. He struggled to make it round a 40minute hack. He is not perfect, he’ll never be completely ’right’ but I feel he can cope with his work. Adding the protein has made a bigger difference than the three Bute trials I’ve done over the last couple of years when I’d put him on 4 a day with no change. I won’t bother with the CAG test, if he does have it, it doesn’t make any difference as I’m already following the protocol and there is no other treatment. If he doesn’t have it, he obviously needed a bit of a diet change and that’s all. But I suspect the former. Knowing makes no difference to me or him.

Out of pure nosiness, what have you used for the protein element?

 

[Tiddlypom]

That's interesting about the protein.

I started my PSSM (of unknown flavour) mare firstly on whey protein isolate, switching latterly to pea protein to save pennies. She's looking and moving incredibly well for a 15yo wonky pelvised PPID/PSSM mare.

It was the chiro vet who suggested pea protein.

 

[ycbm]

There is a recent peer-reviewed study by the foremost specialist in equine neuromuscular disease (Stephanie Valberg at the MSU Neuromuscular lab) showing that the commercial genetic tests (CAG/EquiSeq) are not accurate. The variants they are looking for are present in >25% of normal horses and are not predictive of either the presence or absence of PSSM2. The paper is open access on EVJ so available for anyone to read.
https://beva.onlinelibrary.wiley.com/doi/10.1111/evj.13345

.

I have been waiting for that research, thank you. It confirms my decision that I will not test, nor allow anyone else to test, for type two in a non symptomatic horse that I own.
.

 

[ycbm]

That's interesting about the protein.

I started my PSSM (of unknown flavour) mare firstly on whey protein isolate, switching latterly to pea protein to save pennies. She's looking and moving incredibly well for a 15yo wonky pelvised PPID/PSSM mare.

It was the chiro vet who suggested pea protein.

This is really Interesting because many of them respond to various amino acids (mine did well on alcar) and they are, of course, protein building blocks. I wonder how many would do better just on a very high protein supplement.
.

 

[quizzie]

This is really Interesting because many of them respond to various amino acids (mine did well on alcar) and they are, of course, protein building blocks. I wonder how many would do better just on a very high protein supplement.
.

For maximum benefit with mine, I use a combination of Pro 3 Amino (Lysine, Methionine and Threonine) plus isolate whey protein, together with Nano-E. If you look at the MSU site I linked to earlier I am broadly following the dietary recommendations for MFM in terms of dietary compostion...it has wrought significant differences to my horse. The high fat diet for PSSM 1 actively made him worse, even with vit E. I think there is a lot of individual variation.

 

[bluehorse]

Out of pure nosiness, what have you used for the protein element?

Whey isolate. It’s supposed to be the best thing to use. You can also use pea isolate which I would prefer, but I think it makes him footy.