I have an 18 year old ~1100-1200 lb French Coach/TB cross mare that was diagnosed with EPSM through a muscle biopsy performed by Dr. Valberg. We had her tested after a tying up episode in August of that year. Recently, after reading some literature on Dr. Valberg's website, I began feeding her Releve. She had been doing well on it, but recently, she had a tying up episode (her first since her original diagnosis).

After her diagnosis in 2006, we started her on a diet of low carb grain with vegetable oil (along with free choice grass hay) and later began a controlled exercise program. She was not willing to consume the recommended amounts of oil (about 2 cups per day). We were eventually able to get her to barely tolerate 0.75 quarts of Omegatin (20% fat) plus about 0.25 cups of oil AM and PM (she often does not finish it). She was able to compete as an event horse at Training level in the summer of 2007.

In May of this year, I switched her to Releve concentrate with no added oil. She�s an easy keeper and so only gets 0.75 quarts AM and PM plus free choice grass hay. She was on 12-24 hour turnout with no grass. I let her graze on grass occasionally- no more than once a week for about 30 minutes, and most often not that frequently. In late July and August, she was in the best condition that any of us remember her being in since June of 2005. She was sleek, athletic looking with good muscle tone, and eager to work- enthusiastically conditioning, schooling and competing at Novice level eventing. We thought that the Releve had a lot to do with her improved condition.

On September 7th, we participated in a competition where I noticed her energy lagging compared to earlier this summer during the cross country phase. She completed the competition, but without her usual vim and vigor. I gave her the 8th off, had a great dressage school on the 9th, gave her the 10th off and then took her for a cross country school on the 11th (I purposefully kept her work lighter as she had another competition on September 13th and I wanted her to be fresh). During the cross country school she felt �heavy� and downhill. I began to get runouts at very small fences- not typical for this mare (and a symptom we noticed when she was first diagnosed in 2006). My trainer got on her to see how she felt- she jumped okay (my trainer gives her a much more confident ride than me), but when they stopped, the mare's shoulder muscle was spasming and continued to do so for 3-4 minutes. She lagged the other horses on our hack home.

I called my vet- he suspected that she was tying up and suggested steady work with no jumping, long warm-ups and long cooldowns. On the 12th, we exercised her for about 50 minutes- mostly at the walk, including some hills, with about 10 minutes of trotting and cantering on flat ground in the middle. She did not want to engage during the trot and canter work. As I walked her out, the shoulder muscle was spasming again, though not with as much amplitude as the day before. On the 13th, when I brought her in to tack her up- she stood in a somewhat parked out position- front feet slightly forward, hind feet slightly backward. I called the vet again and he prescribed 3 days stall rest plus 5 ccs Banamine AM and PM. He also wanted me to cut her grain and add 1 cup of oil at each feeding. (we obviously scratched from the competition).

She does not eat any of her feed when oil is added and I am not sure whether or not it is necessary given the composition of the Releve. My trainer and I began to think that she needs a larger ration of the Releve itself in order to provide enough energy to her muscles. I don�t think that my vet is familiar with Releve as he wanted me to feed her less to remove as much starch from her diet as possible and my understanding is that Releve is about as low in starch as you can get (9% NSC). After trying oil for a couple of days, we went back to just plain Releve, but we begin increasing the amount to get her up to 1.5 quarts.

Nothing has really changed with this horse�s management during the time leading up to these episodes. The primary things that we can think of are as follows. (1) The event on the 7th was her first one day event this summer- she had to do all 3 phases, did not get a lot of warmup for each phase and spent a lot of time on the trailer- both traveling (2.5 hours each way on that same day) and while waiting for her time. (2) She also spent the night before in a stall. (3) I worked her lightly after the event on the 7th (though she often got two days off per week). (4) the weather became suddenly cool for several days- also, just prior to the cool weather, I had body-clipped her because her winter coat had come in thickly and I didn�t want her to overheat at any competitions- making her perception of the coolness greater.

In addition to EPSM, this horse also appears to have some degree of anhydrosis (very unusual in VT). She pants more than she sweats after exertion- she has always done this to some degree, but we noticed it getting worse over time and she overheated without sweating at all during a jump school in June of this year. She is now on One AC plus a daily (no sugar added) electrolyte.

My vet drew blood on September 16th while the mare was on stall rest. Her CK and AST levels were normal, but Potassium was below normal. We began giving her 30 - 60 minutes turnout in a small paddock and added light salt to her diet to supplement Potassium. After about 5 days of this light turnout, we began to give her roughly 8 hours of turnout.

On 10/5, I rode her for the first time since 9/12. We did 30 minutes of walking, mostly on the flat, but there are two short hills she has to climb to leave and return to the property. One is gradually, the other quite steep. As we returned to the barn, she had another episode- high respiration, stiffness, muscle tremors in the flank and shoulder. On 10/6, I rode her again, but this time only for 20 minutes at the walk on flat ground- she did fine with this.

On 10/7, my vet exercised her on the lunge line at the walk trot, and canter for 5-10 minutes and then drew blood about 45 minutes later. Her Potassium was normal, but CK was 8350 and AST was 3980.

While waiting for the bloodwork results, we transitioned her to 16 hour, then 24 hour turnout and I continued the program of walking her for 20 minutes each day with about 2 minutes of trotting. She was fine with this except for one day where she had a high respiratory rate and slow respiratory recovery after walking up a very slight incline from the outdoor ring to the barn after her 20 minutes of exercise.

Now that we have the bloodwork back, I am going to scale her back to just 15-20 minutes of walking on the flat (no trotting at all).

I am not sure what to try next to manage her. She does not find oil or powders palatable- so I was hoping I could feed the Releve alone, without any added fat. The fact that she tied up for the first time in 2 years after 4 months on Releve has me concerned that feeding the Releve alone is not sufficient.

At 18, should she be retired? She still seems to relish being worked- she's much happier working than she is being a pasture pet.

I'm sorry for the long email, but I am definitely in need of expert advice.

Thanks so much for reading.

Nicole, Re-Leve is a good low starch and sugar and higher fat feed, but you need to calculate to feed at least 1 pound fat per 1000 lbs of horse per day to most effectively control problems associated with EPSM. So, I think the main problem here is not enough fat in her diet, not anything else that was at all different. You need to weigh the amount of Re-Leve she is eating. Re-Leve is 10% fat so every pound has 1 x 0.10 = 0.10 lb of fat. So, 10 lbs of Re-Leve per day would have 1 pound of fat. You may not want to feed quite that much of this feed, though. My best recommendation for a horse that won't eat feed with oil but needs the fat is to stick with a higher fat feed like Re-Leve or Omegatin (20% fat) or other high fat and also low starch and sugar feed, and gradually add a 100% dry fat supplement to get to the needed fat level. There are several dry fat supplements on the market (Cool Calories, Buckeye Ultimate Finish 100) just remember that they weigh half their volume. So, it takes 2 cups dry fat to equal the fat in 1 cup of oil (0.5 lb of fat). I think that you will find your mare is will have much better control of her tying up issues when there is enough fat in her diet. Good luck, and definitely let us know how things go!

Thanks Dr. Valentine.

I don't think my mare will eat 1.5-2 cups of dry fat per meal- it seems like a lot, though I am willing to try.

Alternatively, I will need to start from scratch and figure out a different base food, pursuing either of the following:

a) something that absorb liquid oil better than Re-leve (perhaps using cocasoya- I haven't tried that yet as it's not easy to get in my local area).

b) something higher fat than Re-leve so I don't need to add as much fat

My trainer and I had talked about alfalfa pellets she was concerned about the calcium/phosphorus ratio.

The barn where I board is changing its main feed from Blue Seal Vintage Racer to Blue Seal Vintage Performance LS, which is 17% NSC and 12% fat (Blue Seal is marketing this as a low starch feed for metabolically challenged horses).

Is a 17% NSC feed be low enough starch to use as a base for an EPSM diet?

(I can continue to get her a special grain- but I was just wondering if I can consider this product.)

Other alternatives I am considering are:

1) keeping her on Re-leve (cons: very expensive and doesn't absorb added oil very well)
2) switching her back to Omegatin
3) putting her on Carb-Guard (cons: might not be palatable enough- I tried this once early on and I think she didn't eat it)
4) using hay stretcher or alfalfa pellets or beet pulp- but I am not sure whether this would be better or worse than a commercial mix and I don't know the NSCs for hay stretcher

Thanks!

I have had fabulous success with my horse by feeding her soaked alfalfa cubes with oil, and mixing in a bit of low starch feed. You only have to soak the cubes a short time until they fluff up, then the oil soaks right into the resulting mash. You can use as many or as few of the cubes as it takes for her to eat it all up--I'd say 8-10 works for me. But when she goes off her oil, I've made huge buckets of alfalfa mash if that's what it took to get the oil into her. It hasn't failed yet. She also gets about a pound of Nutrena Lite feed 2x/day--11% NSC, I think? Before that I was feeding her Triple Crown Lite, also low starch at about 16% NSC.

This new Blue Seal feed sounds very good as a base feed for an EPSM horse. If your mare would accept some oil and some dry fat, along with the fat from the higher fat feed, calculated for that at least 1 pound fat per 1000 lbs of horse per day, this should work. Every pound of the 12% fat feed will have 1 x 0.12 = 0.12 lb of fat, every cup of oil will have 0.5 lb fat, and every cup of dry fat will have 0.25 lb fat. You an also consider adding rice bran powder to help add fat. Rice bran is 20% fat so every pound has 0.20 lb of fat, although it does also have about 22% starch and sugar. Alfalfa pellets are great (they are high in calcium and low in phosphorus but that is not at all a problem - it's when phosphorus is high and calcium low that there is a problem) but not all horses like them with added fat. Any feed that is hay/fiber based should be plenty low enough in starch and sugar to work well. Soaking any feed in water helps to absorb fat. You may have to work on a combination that she likes well enough to eat all the time. Carb Guard won't be any help here, though. As always, good luck!