What To Expect Following Diet Change


Although it is not possible to predict exactly what you might see in your horse following diet change, this will try to give you some ideas. The information below is based on observations we and horse owners have reported in biopsy-confirmed and suspect EPSM horses following diet change.

If your horse has a problem with “tying up”:

As owners of horses that “tie up” are well aware, these episodes can be very unpredictable. It is thought that 2-4 months following diet change are necessary for the muscle metabolism to “adapt”. Some owners have reported improvement in their horses within a few weeks of diet change — this is usually reported as an increase in energy. Some owners report a longer stride and better way of moving within a few months of diet change. An interesting observation is that, in some horses that have “tied up”, somewhere between 1 and 4 months, when the horse has been doing very well, there may be one or more repeat episodes of “tying up”. These episodes are generally described as milder than those prior to diet change. With continued diet therapy these horses have continued to improve, with apparent control of the “tying up” problem, so don’t panic if this happens to your horse. We don’t exactly understand why some horses seem to have to go through this “hump” period.

If your horse has loss of muscle and energy. and/or stiff gait:

These problems seem to improve beginning at 1-4 months following diet change, with steady improvement for many months. Stiff hind limb gait is common in horses with EPSM, and may begin to show improvement within 2-4 months. Generating a proper canter appears to be the most difficult gait problem to correct but, with time and slow steady schooling, EPSM horses can often learn to “carry themselves” at the canter. Horses with “shivers” or “stringhalt” may continue to have some noticeable abnormal hindlimb action, even after long-term diet therapy. Backing may also continue to be difficult for severely affected EPSM horses. If your horse has severe loss of muscle it may take up to a year or more to recover. A small number of horses seem to go through “a bad time” at 2 or 3 months after diet change and, if the disease is severe enough, even diet change may not stop the progression to severe weakness.

Other changes:

Horses that have been previously “back sore” may show increased flexibility with a decrease in signs of back soreness. Attitudes interpreted as “grouchiness” under saddle or during work may improve. Some horses that have been reluctant to hold their feet up for the fartier find it easier to stand for hoof trimming and shoeing.

When do you know if your horse will respond to diet change?

As has been said, this can vary quite a bit. If after 6 months of diet change you see no improvement, it is likely that diet change will not be an effective therapy for your horse.

Dr. Beth A. Valentine
Oregon State University
Corvallis, OR 
Phone: 541 737 3261
Fax: 541 737 6817
e-mail: Beth.Valentine@oregonstate.edu