Hi Dr Beth
I have been looking on your website for an answer to my horses problem.

However I am not sure if my horse has EPSM symptoms or not. He is a 14 year old Quarter Horse gelding, about 530kg, a very good doer.

For the last 2 years at around the same time of year May/June/July has had a sore back just behind the saddle area on the right hand side of his back and then goes lame in the right hind. He shows a sort of dipping action in his movement. The vet last year diagnosed bad saddle fit, so I changed the saddle and this year the same thing happened. He takes some time to get over this (usually about 3 months) before he becomes sound. Only to have it happen again this year.

His symptoms are:

Sore back (he had a muscle spasm the day after a dressage competition and was lame)
Lame right hind (mainly at trot & canter) Although last year even walking him he dipped to one side.
Swings round (as if to bite - but never does, just warns)when putting saddle on or commencing to do up girth. However if I do girth up one hole at a time after his first initial reaction, there is no problem.
Stumbling when ridden (front feet)
Very lethargic when ridden
Will not gallop around paddock with his mate (tries but then stops.
He doesn't seem to have tight muscles.

On learning of EPSM from a contact in Australia I changed him over to an oil diet. He has been on this for the last 3 weeks. Prior to that he has had about a months rest (but turned out).

I am building up his canola oil to 550ml (as he weighs about 530kg). He is currently on 375ml. Plus Speedibeet, Rhodes Hay, Rhodes Chaff, salt, Vit & min supplement. I have taken him off all sugar, grain, etc.

I also have started using a grazing muzzle to keep him off the grass as he is a good doer and I have been told the grass might be causing him problems. I live in a tropical climate and he is on Kikuyu. Which I am told is very bad for horses. He has always been supplemented though, but maybe not enough.

I guess it is too early to tell if the diet is helping.

Over the last couple of weeks I have attempted to exercise him(up to 30 mins only) He goes alright for a couple of days (walking only) then goes sore again. I can tell because he stops, and he is very lethargic and doesn't want to go faster or further. So I stop riding him for a couple of days.

Should I keep riding him? I should mention when I lunge him he was not lame at the trot, but when I get on him he is.

Basically I would like to know if these sorts of symptoms could be EPSM or are they too mild?

I am not sure if further information is needed as well. Any help or advice would be appreciated

Thank you

Amanda, what you describe could very well be EPSM. As it turns out, unexplained hind limb lameness is actually more common than tying up in EPSM horses. Back soreness is also a sign, and some EPSM horses have shown only back soreness as their issue. Put that together with lack of energy and stumbling and I absolutely agree with diet change. Your diet plan sounds good, just remember it takes about 4 months for horses to fully fat adapt and there can be ups and downs during this time. As much exercise as possible is also important. I try to let the horse be my guide as to how much exercise is too much. If he gets stiff or sore give him a few days off with turnout paddock time and then try again. Any improvement early on, even if it does not last, is a good indication that you are on the right track. If he is improving by 4 months or so he can continue to improve for some time. I certainly hope this will be the case, and please let us know how things go!

Hi Dr Beth
Thank you very much for your response. I will definitely keep on with the diet and what exercise he can tolerate. I have gone back to walking him in hand or on the lunge until he feels better with that.

As he is a quarter horse is there some sort of test my vet could do to determine if he is having EPSM problems. I know there is muscle biopsy, but I don't think I could get this done where I live in Australia (?) and I probably wouldn't go there just yet. What does the hair test that has been mentioned determine?

Thanks once again for your invaluable help and informative website.

This sounds like a good plan. As to testing, there is a genetic test for a change in the GYS1 gene that identifies some, but not all, EPSM horses. It can be performed on DNA extracted from pulled mane hairs sent to Dr. Stephanie Valberg at the Neuromuscular Disease Laboratory at the University of Minnesota Veterinary College (where they call this PSSM - same as EPSM). You could certainly try this but, given his vague/subtle clinical problems, I suspect that, even if he is an EPSM/PSSM horse, this test would be negative. In Quarter horses the test more easily picks up horses with more obvious signs of muscle issues such tying up. It couldn't hurt to try, though. Just remember that a positive test is definitive, but a negative test does not rule it out. But your best approach here may be the diet and exercise therapy trial. Good luck!

Hi Dr Beth
I have just found a new feed product I can get here which is a powdered coconut oil supplement. It says on the label 30% starch (apparently from purified corn starch).
Nutrient Specs:
DE 29.4 mj/kg (3.18 MCal/lb)
Oil: 70% (as coconut oil)
Fatty Acids:
Lauric Acid (C:12): 44.5% (as % oil)
Myristic Acid (C:14): 17.5% (as % oil)
Palmitic (C:16) 8%
Oleic (C:18.1) 6%
Would it be safe to add this to my horses diet as an "extra" to help build some topline? Is it too high in starch?
My horse has been on 500 ml oil now and amazingly is not putting on weight, but actually has lost his "belly" and is looking good except for some lost topline.
His soreness is gradually easing and I am increasing walking out time.
I had some blood tests run recently which were all ok except proteins & globulins were up. Lab report said "horse has mild hyperglobulonaemia suggesting some recent infection, inflammatory focus or other immune stimulation, including parasitism or skin disease." Not sure what this means, but vet said to put him on bute for 5-7 days.
Still not sure if EPSM affected or just a chronic back injury, but diet is doing him wonders, so will stick with it.

I'm so glad to hear that things seem to be improving so early on in diet change. This is a really good sign that you are on the right track! Just don't panic if he has more bad days in the future.

This high fat product sounds OK, but having starch means it is not as good as straight oil, which is 100% fat. If I were you and he keeps eating the oil I'd stick with that for another few months and see how things go. If he starts refusing the oil this product can help, but I'd still want to have some added oil.

I'm not sure what to make of the lab report either, other than to say there are a lot of "blips" that can occur in equine lab work that don't really mean anything. My best advice there is to just repeat this in a few months and see what's up. The normal ranges for lab data include 95% of the population. That means that 5% are normally either above or below that range.

Hi Dr Beth
I have had a few ups and downs since my last post. However he has improved considerably and his hind limb lamenesss is going. I have also had someone do some type of "muscle stretching" for his back and this seems to help as well. However he is now not eating all his speedibeet mixture with the oil (2 1/2 cups per day). What other feeds are suitable to feed other than speedibeet? I have added 2 cups Lupins to try and build his topline again. Can you feed Copra meal? I can get some rice bran feeds but these have molasses in them. would this make it too high in sugar. I could add some Lucerne hay, but I am worried about excess sugar and possible potassium levels. In Australia, we dont have as much choice or brands as you have. Any suggestions would be greatly appreciated.
Thank you.

Well, this is good news about his improvement. So now you'll just have to get creative about getting him to eat right again. Adding a bit of anything that he really likes, even if is is a little "sweet", is fine if it keeps him eating the right amount of oil. A bit of Copra meal, or rice bran, or even a small amount of grain or molasses or apples/applesauce, whatever it takes. Lucerne is even better as it really is low in starch and sugar, and a little bit won't add a lot of potassium (which is only an issue for HYPP horses). He ate the speedibeet and oil before and it is not uncommon for horses to eat well and then suddenly decide you've put a dead rodent in their feed bucket :) Keep at it and I'm sure you'll get him back on track. I hope this helps, and please keep us updated!

Thanks Dr. Beth for confirming what is OK to add to his feed to get him to eat it again. I will do what you suggest. Thank so much.