Ask the Vet: Vitamin E & Muscle Disorders

Courtesy of AAEP

Question: My horse has PSSM. He’s 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 intolerence.

Is it unusual to take such a long time to recover and will symptoms possibly always be present?

Answer: Luckily, horse’s muscles heal completely, with minimal scarring, following an episode of tying up. The healing process usually takes several months and in cases where muscle mass appeared to be lost following the initial episode, most horses will appear normal within 6 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 and relapses in clinical signs can occur if fitness levels decrease, diet changes or 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 1000 IU/day has been recommended. Please consult with your veterinarian to determine if your horse could benefit from Vitamin E supplementation.

Question: I have the opportunity to purchase a very nice horse at a favorable price due to shivers. I have read that Vitamin E can help control the problem. What are your suggestions?

Answer: The exact cause of Shivers is unknown, however genetic, traumatic, infectious, myopathic or neurologic factors have been suggested. At the present time, there is no cure for Shivers and few treatments have been found to be effective in controlling this disease. Some cases have reportedly shown improvement in clinical signs following periods of rest, however once exercise resumes clinical signs often return. Dietary modification to a high-fat, low carbohydrate feed along with a regular exercise program and daily turnout may reduce the frequency of muscle spasms in some cases. Additionally, supplementation with a natural source of Vitamin E (1000 IU/day) may improve clinical signs in some horses with Shivers.

Unfortunately, the long term prognosis for athleticism, and in some cases life, for horses with Shivers is poor due to the progressive nature of the disease and lack of effective treatments. Over time, spasms may occur more frequently and worsen in severity. In severe cases, muscle wasting and weakness may also develop necessitating humane euthanasia.

If you are considering purchasing a horse with suspected Shivers, consultation with your veterinarian is recommended. He or she will most likely recommend a thorough evaluation to confirm the diagnosis by ruling out other possible causes of any gait abnormalities that are present.