Three Diseases Related to Vitamin E 

There are 3 diseases seen in horses that all may be related to vitamin E in some way. As vitamin E is a potent antioxidant, it may help prevent and/or relieve symptoms of these diseases. They are in order of how likely you would be to see or hear of them. NOTE – the only one of the three disease involving an infective agent is EPM….the other two do not involve a “bug”.

EPM - Equine protozoal myeloencephalitis
A parasitic disease (protozoal) that affects the brain, spinal cord, and nervous system. It can cause mild signs of incoordination in some horses and can quickly make other horses so unstable they cannot get up. Lowered immunity due to low dietary antioxidant levels (vit. E) may predispose horses to development of EPM when infected and supplementing vitamin E can help recovery.

EMD or EMND – Equine Motor Neuron Disease
A disease that affects the nervous system of horses, specifically those nerves controlling skeletal muscles. This disease resembles human amyotropic lateral sclerosis (ALS -Lou Gehrig's disease). Horses with EMND show a rapid onset of trembling, excessive recumbency, low head carriage, a constant shifting of weight on the rear legs, and muscle atrophy. Horses have low levels of vitamin E in their tissues and blood. The absence of grazing time (also hay without adequate green color) is a predisposing factor in EMND – relating to low vitamin E intake. Mostly occurs in mature horses.

EDM - Equine Degenerative Myeloencephalopathy
Disease of the spinal cord and brain stem. Affected horses show ataxia (incoordination), which occurs early in life and can stabilize or progress to become so severe that the horse must be euthanized. Horses have low levels of vitamin E in their tissues and blood.
Harold Hintz, Ph.D., a respected nutritionist from Cornell University, and others have recommended daily intake levels of:

  • 450 IU/day for maintenance
  • 720 IU/day for late gestation
  • 950 IU/day for lactation
  • 1,000 IU/day for intense work
  • 6,000 – 10,000 IU/day for horses showing signs of neurological disease

In barns where horses are diagnosed with EMND, it is wise to ensure all other horses in the barn be supplemented with vitamin E at the above levels, due to the likelihood of low vitamin E in the feeding program.

The Tribute program, when fed as directed, meets or exceeds these levels in most cases, except for the 6,000 – 10,000 IU/day level. These levels would require added vitamin E as a supplement. We offer straight vitamin E supplements on the price sheets.

many supplements contain SELENIUM and Vitamin E….often, to achieve the desired levels of vitamin E, the level of SELENIUM may become TOXIC. If someone decides to use a supplement, suggest they use one WITHOUT SELENIUM.

D.J. Burke, Ph.D.