Hi Dr. Valentine,
I have a few question regard my 5 yo Shire (Monte) for which you read the muscle biopsy.
1. I started EPSM diet on 10/10/07. So I guess this is when he goes through the "rough" spot. He almost seems worse than when I first noticed it. LOTS of trouble turning and backing. When purchasing him I didn't know that he had this problem and was looking for a horse that did not have to be ridden or worked with all the time. Am I making him worse by not exercising him or just not helping? (That was a big thing when looking for a horse, I wanted low maintanence!, definitely not the case, in fact, the highest maintanence horse I've ever had!)
2. I have seen that selenium is important depending on area. How do I find out if this is something he needs and if so how much?
3. I am feeding him close to a bale of alfalfa/day. I tried to mix in some orchard grass, but he snubs it. I hear so much good and so much bad regarding alfalfa. Could this make him flighty?
Thank you in advance for you assistance. This has really been a challenge!

Yes, this is just about the time that a lot of EPSM horses have some troubles. I suspect that they may start to do more than their muscles are quite ready to handle. If so, they should get stronger from the experience. As to exercise, if he has plenty of turnout time (24/7 is ideal), especially with pasturemates to play with, this will go a long way towards keeping his muscles conditioned and able to fully use the fat in his diet. Hopefully he will become less and less high maintenance with continued time on diet change.

As to selenium, ask your veterinarian about selenium in the soil in your area. If you look at the selenium map in the article in the Contents of this site you'll see that much of the east coast and west coast is very selenium deficient, with variable levels elsewhere.

Alfalfa doesn't make a horse "hot" but the extra calories in alfalfa might. I'd give him a bit more time on an EPSM diet to see if he doesn't settle down on his own. There really isn't anything bad about alfalfa hay in fact it has good quality protein and more calcium and vitamin E than other hays, which is a good thing. So don't worry there.

Kim, I don't know if this helps, but you can find a map of soil selenium content online at

Selenium

This'll give you an idea whether you are in a selenium-deficient or selenium-rich area.

In my own experience turnout is the most important factor next to diet-change for managing EPSM.

Thank you for your responses.
Monte is only stalled to eat breakfast and dinner, otherwise he gets to be a horse 24/7! So I guess I'm doing at least one thing right!

Also,
Does soaking hay help?
I've heard that soaking hay for 30-60 minutes reduces water soluble carbohydrates 30-50%. ???
Kind of a pain to do, but if it would help I could manage.

Soaking hay does help by dissolving out sugars. I'd have to look up what percentage reduction you can get with soaking, but it certainly could be worth trying. If he gets back on track you can see if you really need to do this.