After six months of web searching, vet exams, massage therapy and chiropractic appointments I took a hair sample test from my 4 year old warm blood gelding and sent it to equiseq to test for genetic markers for PSSM2. I just got the results back and my boy is negative for those but shows a positive gene for RER. Recurrent exertional rhabdomyolysis. He certainly shows exercise intolerance and has been mr grumpy since the day he arrived with us as a yearling. He is on grass, not fed grain but loves carrots. So I reduced his time on grass in July, cut back to one carrot a day (this has to go too I’m sure) and started feeding a high protein low starch ( nutriena top balance) plus platinum performance equine. He lost a ton of muscle on his hind end in June and now has a little of it back, but has developed a little fatty deposit each side of his tail and along his crest. He is not over fat. I would say his body condition is a seven. He is out all the time. I ride him…or try to, 3-4 times a week, just slow and steady long and low arena work and some hacking out.
I thought he had a gelding scar…or some sacroiliac problem, but this is the reason. What can I do to help him feel better and keep him happy (us both happy actually)?
I’ve never heard of EPSM causing fat deposits but hormone imbalances do cause that. I’m thinking of Equine Metabolic Syndrome and Equine Cushings disease (which terms are often used interchangeably because of similar symptoms, but the two are not the same).
As for the EPSM: there is no genetic test which accurately diagnoses Type 2 EPSM. This article from Michigan State University explains why in detail and kind of slams some of the laboratories which are making unscientific claims:
https://cvm.msu.edu/research/faculty-research/valberg-laboratory/type-2-polysaccharide-storage-myopathy
However, there IS a test, which is an examination of muscle tissue from a muscle biopsy. So my point is that even though your horse does not have Type 1 EPSM, he may have Type 2.
In addition, the following link talks about which type to test for (see item number 11) and basically says that for warmbloods, both hair/genetic test and muscle biopsy should be done:
https://cvm.msu.edu/research/faculty-research/valberg-laboratory/type-1-polysaccharide-storage-myopathy#11.-how-do-i-know-if-i-should-do-the-genetic-test-or-the-muscle-biopsy?
So I would have your vet think of other possible causes of your gelding’s symptoms and ask him/her specifically to evaluate your horse for Equine Metabolic Syndrome, Equine Cushings disease, and if you still suspect EPSM, a muscle biopsy.
I thought about the muscle biopsy, but after talking with my vet and to equiseq and understanding that if he has the genetic markers he would have pssm2 I went with the hair test as to not stress him out by having to have a chunk of muscle taken from his hamstring. The treatment is the same regardless, diet and exercise. I don’t think he has ever really tied up while I have ridden him, but I know he gets some type of muscular discomfort occasionally when I lunge him as he goes bonkers…as most of the time he is slow and steady.
It sounds like you are doing the best things, low-sugar diet and exercise. Turnout is very important for horses with EPSM. As for treats, if you are not feeding alfalfa, use it for snacks to replace the carrots. Most horses love alfalfa. Oh, and ask your vet about the carrots. Since they are so small relative to the rest of his food, the sugar in one carrot may be inconsequential; at least that’s what my vet told me.
You’ve probably read this already, but if you haven’t (or for those other readers who are interested), this is a nice article:
https://ker.com/equinews/update-pssm-horses/
“Regular daily exercise is extremely important for managing horses with PSSM,” stressed Valberg. “Even 10 minutes of exercise has been shown to be extremely beneficial in reducing muscle damage with exercise. Once conditioned, some PSSM horses thrive with four days of exercise as long as they receive daily turnout. For riding horses with type 2 PSSM, a prolonged warm-up with adequate stretching is recommended.”
Great article. Thank you.
