I adopted 2 pregnant PMU mares in 2003. One of them we were told was saddle trained, so we started riding her. She was very sweet natured but bucked off anyone who got on and asked her to move faster than a trot. we went through 3 trainers and endless advice to no avail. I found an article that changed my life. I have the editors permission to reprint this and I feel she had saved my horses life. I have since found out that this is very common and many vets do NOT support the idea that EPSM is VERY VERY common in ANY horse not only drafts and draft crosses. Before you sell your horse because you think they are lazy and unwilling, read this-I think it will help. Anything I have read on EPSM say things about colic or health problems. My mare showed NO signs of any of that. We changed her diet and she is a totally different horse. I am hoping this helps at least one frustrated person out there......
--------------------------------
Adventures in EPSM
Tristan’s Road to Recovery
REPRINTED BY PERMISSION www.horsesmaine.com

by Lynda McCann

I mentioned in last month’s Horse’s Maine that Tristan has been diagnosed with EPSM. I thought I would amplify a bit, since it’s been one of the most confusing and frustrating horse experiences I’ve ever had, and since it also seems to be an up-and-coming thing that people really ought to know about.
I bought Tris when he was two and knew very little. I’ve worked with young horses before and vowed that I would do it again, until it stopped being fun. Tristan was very athletic and powerful, somewhat large (15.1 hands at 2; 16.1 now), and a bit volatile. This could have made things very difficult, but what I had going for me was a wonderful temperament. Tristan has a strong desire to do the right thing, to be a good boy, and this combined with his very strong curiosity and interest in new things made him a quick learner. He learned to load and travel in the trailer with no problem at all. Each new piece of tack he learned to wear was greeted very nervously but with acceptance the first day; the second it was usually, “Yeah, yeah, yeah, been there, done it.” The first sound of velco ripping and the first swipe with the sweat scraper almost caused heart attacks, but these too were quickly accepted. Learning to lunge went well, even in my then-unfenced arena, although I found him a curious combination of lazy and volatile. The only thing that seemed to take him a long time to learn was to pick up his feet. He just didn’t want to pick up those back feet and, when he finally did, he would often just rest the toe on the ground rather than actually picking it up. This tendency got better over the years, but persisted somewhat till recently.
Tristan was lunging well and was fairly good to handle by the time I went to get on him when he was three. A friend helped. I lunged him thoroughly and then she held him at the mounting block (I’d already done work with him there too, and he was used to my putting some weight in the stirrup). I cautiously started to get on… I think. Then I was on the ground, my friend was saying, “What happened?” and Tris was long gone. I think my first words were, “This just stopped being fun.”
So Tris went to a professional trainer, a lovely rider and a sweet patient person, who worked slowly and carefully with him and actually got to the point of walking around on him with a lead. Then she tried trot and was violently bucked off (I’ve never seen anyone with a black eye that bad!) and that was that. I had him checked by a vet/chiropractor, with nothing being found.
Six months later Tristan went to Sherrye Trafton at Sable Oak Equestrian Center in Brunswick. Sherrye did lots of natural horsemanship with Tris. Lots of groundwork and desensitizing, all of which was wonderful for him. When she finally got on him, he was on his own and it was a non-event. Soon she was walking, trotting and cantering on him and he was being good. Then two weeks before he was scheduled to come home he had another bucking fit for no apparent reason. Sherrye bailed off and Tris kept on bucking. Sherrye wanted to keep him for another month, but I’d reached the end of the budget for that particular project (sometimes, perhaps, budgets should be extended, no matter what).
So Tris came home and I took over. Walk and a little trot. I was scared to death. At the same time, I was shocked to find that he was lazy. Not just a little lazy, but extremely lazy. And yet, at the same time I felt like I was riding a ticking bomb. He just didn’t feel right. Not like any other horse I’d ever ridden. After about a week he dumped me. Same as before; he was there and then he was gone and I was on the ground (making me probably the only person who has been dumped at the turn on the forehand!) Again, I couldn’t tell you what happened. A bee or something, I thought.
A week after that, after we had walked a slow-motion circle (Tristan always seemed to move in slow motion), I got the bucking. And leaping, plunging, and rearing. I stayed on so long that if I were in the rodeo, the buzzer would have gone off. I was more scared to come off. When I finally did, I landed on my side on top of the 4’6” fence surrounding the ring. And Tris bucked on. He finally stopped, looking bewildered and repentant (a look I’ve come to know so well). I collected the reins (they’d broken in two places) and Tristan, hobbled to the barn (I had bruises that could be measured in feet rather than inches), untacked him, and sat down and cried. And Tristan became a field ornament again.
Six months later, now four and a half, Tris headed down to Gray to Hope Springs Equestrian Center and Jocelyn Lewis. Time to start again, but this time I needed him close. Emotionally, for me, I needed to be there to watch every step of the process. Jocelyn was very good to me about that. Yes, I’d had him checked by a vet, and a massage therapist. And we’d had some minor OCD in his hock taken care of.
Jocelyn did a good job with Tris, who now seemed to be more emotionally ready to deal with being a riding horse. There was no bucking. For four months, Jocelyn rode Tristan four days a week and he did well. But there was a tightness in his shoulders that just wouldn’t go away, and he always looked like his legs were being just slightly held back by an unseen hand. The last month I began riding him a bit, under Jocelyn’s tutelage. I was far too scared at this point to ride him alone and yet I was becoming obsessed with riding him. I felt that if I gave up, I would also be giving up riding.
Jocelyn moved away, so at five Tristan came to Morgan Hill Farm in New Gloucester and I transferred my dependence to Anna Welch. I was ostensibly in charge of my own horse now, but I knew even then that I couldn’t cope with this horse on my own. I got on by myself several times a week, hyperventilating with my heart pounding. It got better with time, at least emotionally, but it was hard. I began to realize that this was the most difficult horse I’d ever been on. And getting worse. There was that weird feeling that those legs were being held back. Tristan is endowed with a beautiful canter and yet, he didn’t want to use it. When I got confident enough (this year, finally) that I could make him canter, I sometimes got one, emphatic, angry buck (which I sat… mostly). As time went on, he began slowing up or even stopping when you put your legs on. Same for the stick.
Anna rode him during our lesson often. She’s lighter than I am, and stronger. Ok, and better. He went better for her, but not right. We began to describe him as “riding a collection of body parts.” You were forever having to catch errant body parts and attempt to put them back were they belonged. He spooked (often); his head went up and you never knew what he was going to do or where he was going to go (neither did he, as it turns out). He needed the support of the reins to be able to work at all and would get panicky without them. He fought (his own body, not us, we’ve come to realize) at the canter, tight in his back and stiff in his neck. He lunged with his head stiffly in the air. And he would not move forward. Anna once told me, “I used to think that if you would only put your legs on and let him move forward, he would be wonderful. Then I started riding him and found out how far from the truth that was.”
We had problems. Subtle ones usually, but constant and changing. Tris was never the same from one day to the next. What worked one day wouldn’t be what worked for the next. We made progress, but excruciatingly slow progress with tons of backsliding. There were lots of scary moments, a sudden flash where he’d do something bizarre and then look as surprised as we were. This year (he’s now seven) two different clinicians have asked me how often I ride him, then looked at me like they know I couldn’t possibly be telling the truth when I say that he’s been ridden four to six days a week for the past two years, and then gently tell me that he needs more muscle development.
Through it all, he’s looked good. He’s a pretty horse. He’s a good mover, so when he isn’t moving well, it’s not as obvious as it could be. He looks… a little lazy. But what you see is not what you get- the horse I’m riding feels far from the horse you’re seeing. And I’m so sick of being told to “drive him forward.” “I can’t” is not an acceptable answer and yet, in Tristan’s case, it’s been true. If he was not ready to be pushed forward, if he had not been loosened and supplied and mega-warmed up, the sad but true fact is that Tristan couldn’t move forward, often he couldn’t canter at all. But occasionally, for at least a few moments, he’d reach the point where he could. Where the beautiful, soft, huge trot could come out and we wouldn’t be trotting any more; we’d be floating. Or, even more rarely, where his gorgeous canter would happen and I could sit there all day and love it. Or his hind end would start swinging at the walk and I’d feel his legs come way under me and still keep coming. Those moments would take my breath away and keep me coming back.
We tried everything. I say “we” because, bless her heart, Anna has been right with us the whole time in the search for the elusive “something wrong” that we knew was there. We’ve tried every training technique known to man, and a few others (hey, if standing on your head in the saddle would work, we might have tried it). Tris has been seen by countless vets, two chiropractors, several massage therapists and an acupuncturist. No one could put their finger on anything, although most felt there was something a bit odd, a bit strange.
Which brings us to last June, when I attempted to ride Tristan in a Bill Warren clinic. Tristan was not about to participate. Every time I put my legs on, he bucked. It was the first time I felt any anger in him. I really felt that he would have bucked me off if he could, he was so angry, but it didn’t take long for me to feel that there was nothing left after the buck. He couldn’t have physically gotten off two in a row. He wasn’t really getting much force into the first one.
I didn’t ride for very long; it was useless. The second day Anna rode him for me. She got more out of him- more bucks, too. Again it didn’t last long. Bill said, “You know, the only other time I saw a horse do this, he had EPSM,” and it all fell into place for me. I happened to already know of EPSM. For me suddenly everything Tristan had done in his life (the early bucking? Maybe. I don’t know. I’ll never know.) made sense. I was suddenly full of hope for the first time. Maybe we had finally reached the end of the problem.
Equine polysaccharide storage myopathy (EPSM) is a muscle wasting disease. It has not been known for that long and most people have not heard of it. And yet, I’ve read that it may be present to some degree at this point in 30-50% of all horses. Inability to move forward, inability to canter, trouble going downhill, problems picking up the back feet, shivers, all and more are symptoms of EPSM. There is a lot of information on the internet about EPSM (including a bulletin board devoted to it), much of it coming from Dr. Beth Valentine, a veterinary pathologist at the University of Oregon who has done vast research into the subject. Do a search on EPSM and you won’t have any problem getting information.
I had a muscle biopsy done on Tristan (the only way to diagnose for certain). I had to know. It was positive for mild EPSM. All we’ve been through and he only has mild EPSM. But I’ve talked to people whose horses have it more severely and I thank goodness Tris is only mild. I know someone whose search for that elusive “something wrong” has cost her $28,000, and she has much more to deal with than Tris and I.
EPSM is not curable. It is controllable with diet. Tristan has been on the diet for almost three months now. He is eating one of the newer low-carb feeds that have come out recently and he gets 1 _ cups of vegetable oil in each feeding, 2 times a day. He also gets 1000 IU of Vitamin E each day, and a vitamin/mineral supplement. The low-carb, vitamin E, and especially the oil are the keys (and God bless Morgan Hill for being flexible in developing his diet, and religious about giving it to him). His treats are restricted to one carrot a day (much to his dismay). He gets his normal amounts of hay, but wears a grazing muzzle out in the field (which has plentiful grass. Tristan is a highly efficient eater and could consume vast quantities of carb-filled grass a day). And it’s all working.
For the first month Tristan had good days and bad days. We had days where I lunged him and ended up much more well worked than he did. He could barely go. Occasionally I’d ask for a trot and he’d bound forward for a few strides, giving me hope. We just kept plugging away at it. (Work is also an essential ingredient in controlling EPSM)
About a month ago Tris suddenly turned into a completely different horse. He relaxed. He stopped fighting and softened his back. He bounds forward at the trot more and more often, the unseen hand gone. The canter got better and better and is now soft and comfortable to ride. We spend lots of time working “on the buckle” at all gaits, something he never could do before. Now he can hold himself up; he doesn’t need me to do it for him. He’s much less spooky and when he does spook, he takes me with him and his body goes where we both expect it to (even in a spook, there is a normalcy in it that was missing). There was a hyperactivity that’s gone (Hey, you try riding a hyperactive horse who can’t move forward!) No more sudden leaps that take us both by surprise (I’ve bounced my head off his butt twice in the past), no more collection of body parts. I’ve suddenly got a plain, old, normal horse! He’s filling out (someone said he was a hunk the other day) and gaining muscle. (I think of his physical condition as age two going on age seven.) His body goes where he tells it to and he’s able to carry the forward gaits longer and better.
The most exciting change I think I feel in Tris is in his confidence. It must be a terrible thing to not be able to trust your own body. It’s been fun to ride him as he gains a new sense of his self. Like the day he suddenly realized that he could do a forward trot. The trot got bigger and bigger as we went down the long side, and I left him alone as he played, putting more bounce and loft into the trot with each stride. Perhaps it’s silly, but swear I could feel him grinning.
Now we start off each day slowly. He still needs a long warm-up. Perhaps he always will; I don’t know. He still has more muscle building to do, he has emotional issues to get past, and he may still have some EPSM recovery left. I do know that if I ask for a canter and he says no, he means it. He’s not ready. Another few minutes of trot, or walk/trot transitions, and he’ll take the canter easily and willingly. I’m not sure yet if this is physical or emotional; I just know that if he needs the time, I’ll give it to him. But I know that when he’s ready, he’ll pull out the big, loose, forward gaits and we’ll float once again. We now get to that place each time we ride. He becomes light and sensitive and very willing. And we’re having fun. Finally.
One thing hasn’t changed about Tristan. It should have. He should be a cantankerous, sour horse by now. I’ve come to realize that I’ve been essentially abusing this horse for at least the past two years, making him do things that were almost impossible for him, like cantering. I didn’t know. No one did. If anything though, he’s sweeter and more willing than ever. He seems happy and relieved and he seems to be having fun. I’m amazed by this horse who, against all odds, tried and tried, and when it didn’t work, kept trying anyway. His temperament has gone, in my mind, from merely “good” to heroic. He can have all the time, and anything else, he needs.