Tying Up Syndrome

[PegasusFarmsAppaloosas]

My neighbor has a Mountain Pleasure horse that is at Cornell now because he is having problems with tying up. It started with him when he was on a trail ride, he went out fine and then got more and more sluggish. They had a hard time getting him back to the trailer and he wasn’t his usual mischievous self. After a time he seemed to come out of it and seemed fine. After a couple more episodes of this she called the vet. He ran some blood work and said he was anemic, probably from worms. Now I don’t care for their vet and I couldn’t believe Pete could have worms. She and her husband clean manure out of their pastures every morning and night, their fields are more than adequate for the number of horses in them and they de-worm religiously! So they went with what their vet said, put him on a blood building supplement and dewormed him and everyone else on the farm for good measures. Pete was put out to pasture with no riding and he seemed to be getting better. Blood work showed he was getting better and she was told she could start riding him lightly. We went out, sticking to the flat roads and hadn’t gone very far when he started acting lethargic and didn’t want to walk. We immediately took him back to the barn and after a short time he acted normal again. I again insisted there was no way this was worm related. She was told to put him back out to pasture, and keep him on the supplement. About 2 or 3 weeks later he had another episode walking from the field to the barn for feeding time. They had to go down and get him. She finally said enough was enough and loaded him right into the trailer and took him to Cornell. He was quickly diagnosed as tying up and has been having fever spikes and muscle cramps since last weekend. Pete has been a healthy, mischievous, and steady trail gelding for 2 or 3 years now. He’s an easy keeper so he doesn’t get anymore than a couple of handfuls of a 11% sweet feed that they have made specially for their farm. He’s turned out 24/7 and is very laid back, nothing much phases him and he’s been going to parks trail riding since he was 3. He’s not over worked, they trail ride at a leisurely walk or slow gate most of the time. I was hoping someone could give me a good site or information on tying up, and experience with tying up, or what would cause Pete to suddenly start tying up.

[Ryle]

It sounds like the vet that they regularly use isn't very up on equine diseases/conditions because different muscle disorders have been presented repeatedly in all the equine veterinary journals, horse magazines and equine veterinary conferences for the last several years.

From what you describe, the "syndromes" they are probably trying to distinguish between at Cornell are Recurrent E xertional Rhabdomyolosis, Equine Polysaccharide Storage Myopathy or some sort of dietary imbalance.

Rhabdomyolosis (tying up) has been believed for years to be tied to excessive lactic acid buildup in muscles during exercise, but that is not the case. It is now thought that it may be caused by abnormal calcium regulation in muscles. And recurrent Exertional Rhabdomyolosis is associated with episodes of tying up that occur at slow paces.
Management of horses with ER is focused on plenty of turnout and regular work (no days off in between long rides or heavy training) along with slow warm ups with plenty of stretching. A balanced diet that is low in starches or Non-structural Carbs (grains, corn, etc) and high in fat is recommended.

EPSM causes episodes of tying up because of abnormal glycogen storage and glycogen synthesis. Episodes often occur a short time after starting light work (<20 min. of walk/trot), with the hindquarters being the most affected. Management of EPSM also includes regular exercise, including as much free exercise as possible, change in diet and then slow return to work. Dietary recommendations are to feed a low starch, high fat diet, as well as reduction of sugar in diets (so no sweet feeds or sweet treats).

And 1-2% of their body weight in good forage per day is recommended with either condition, though curbing access to lush grass may be recommended.

Diagnosis of the specific muscle disorder is going to be based upon history, serum chemistry analysis and most likely muscle biopsy.

For good information you can check out these websites:
http://www.cvm.umn.edu/umec/lab/RER_new.html
http://www.cvm.umn.edu/umec/lab/PSSM.html

Cindy D.
Registered Veterinary Technician

[PegasusFarmsAppaloosas]

Thank you very much for your reply and your information.

If he was already turned out 24/7 with little grain and free choice forage, then he probably has the EPMS right?

What would cause such a sudden onset or is this the usual age (I believe he's 5) that they begin showing symptoms?

Since his diet is already mostly forage, would they put him on a supplement then?

Does the fact that he was having these episodes even in pasture mean that it's more serious than if it was only when he was being ridden, and if so, how would this affect his future ride ability?

[Ryle]

If it turns out to be either of those (which can show up suddenly later in life), keeping him on pasture with fat and vitamin/mineral supplementation to his diet would probably be recommended. With both of those diseases, getting a higher fat content in the diet is important. So even if he was on a mostly forage diet he could still have episodes because his energy needs weren't being met.

But until the vets run the diagnostics it's going to be impossible to tell if it is just RER or EPMS.

[krysha_n_helga]

i was goin to she a young dressage and the girl told me that it had but only the once.
I don`t know weather to go and have alook or not?
can they just have it the once or will they have it for life ?
Thank you
Krysha

[Ryle]

Krysha,
It depends on what caused the episode. Tying up can be caused by several different things. If they don't have a diagnosis then I would recommend that you get a very good pre-purchase exam on the horse and discuss with the owner what triggered the episode. Still, without having testing done at the time of the episode or having a muscle biopsy done now it's impossible to say if it will ever happen again or not.

[krysha_n_helga]