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Recovering From PSSM

January 28, 2013

Dr. Holly Bedman explains the after-effects of PSSM in horses.


My horse has PSSM. He has been on high fat food since March and is building muscle, but at what seems to be a very slow rate. He sometimes appears to have signs of exercise intolerance. Is it unusual to take such a long time to recover and will symptoms possibly always be present?

For the answer to this question, we conAsk an Expertsulted Dr. Holly Bedman with the American Association of Equine Practitioners.


Luckily, horses’ muscles heal completely, with minimal scarring, following an episode of tying up. The healing process usually takes several months. In cases where muscle mass appeared to be lost following the initial episode, most horses will appear normal within six months if properly managed and no further episodes have occurred. With proper dietary management (high fat, low starch) and a regular exercise program, most horses show improvement in clinical signs and can lead a successful athletic life. Unfortunately, the key here is management, which means that horses with PSSM are never cured of the disease.

Relapses in clinical signs can occur if:

  • fitness levels decrease
  • diet changes are made
  • the horse becomes ill

If you believe your horse is currently

being properly managed for PSSM through a proper diet and regular exercise program, then other causes of poor performance should be ruled out by your veterinarian, such as an underlying lameness or a respiratory condition, such as inflammatory airway disease. Measurement of serum Vitamin E level may also be valuable as some horses deficient in Vitamin E can show signs of muscle wasting and weakness, which could manifest as poor performance. Horses with muscle disorders may benefit from supplemental Vitamin E. Natural source Vitamin E in a water soluble form, fed at 1,000 IU/day has been recommended. Please consult with your veterinarian to determine if your horse could benefit from Vitamin E supplementation. Get more information on PSSM from the University of Minnesota’s College of Veterinary Medicine Neuromuscular Lab.

— Dr. Holly Bedman, member of the American Association of Equine Practitioners