Equine Protozoal Myeloencephalitis (EPM) is a disease that affects the central nervous system in horses and is caused by two protozoan organisms. Most commonly Sarcocytis neurona and less commonly Neospora hughesi. Sarcocytis neurona is transmitted by the opossum, while the host of Neospora hughesi is unknown at this time.
 

Many horses are exposed to the protozoa that causes EPM, but only a small percentage will develop clinical symptoms of the disease. Symptoms can vary from hardly noticeable to severe neurological deficits.

EPM is a frustrating disease for researchers because there is still much that is unknown about the disease, despite being a significant research focus for many years, and also for horse owners with afflicted horses.

EPM is treated with anti-protozoal medication, which is often paired with supportive care, such as anti-inflammatories. Your horse’s exact treatment plan will be decided with your veterinarian.

In addition to your horse’s prescribed treatment, there are some nutritional strategies to help support your horse during recovery. The nutrient that is most commonly focused on for horses with EPM is Vitamin E. Supplementation with high levels of natural Vitamin E are often encouraged, as Vitamin E is a potent antioxidant that supports nerve function and the immune system. Levels of 5,000 to 10,000 IU per day are recommended during treatment. Blood Vitamin E levels can be monitored and the rate fed can be adjusted for longer term use at higher levels, if necessary.

Outside of Vitamin E, we also want to focus on a nutritionally balanced diet to meet all of the horse’s other vitamin and mineral needs. Multiple nutrients are involved in supporting the immune system beyond Vitamin E.  In many horses, the level of work they are in will change as a result of a positive EPM diagnosis, and if you are no longer feeding at least the label minimum recommended rate of feed per day, the diet should be evaluated.

Muscle atrophy is a common symptom of EPM. In order to support muscle rebuilding, a focus on high quality protein in the diet is key. Providing quality protein that fills in the gaps from forage is achieved by feeding higher levels of the limiting amino acids lysine, methionine and threonine.

We routinely recommend use of Essential K® or Wholesome Blends™ Balancer to support horses during EPM recovery because both products are highly concentrated in vitamins, minerals and the high-quality amino acids needed for muscle rebuilding.

For the idle, average horse, we recommend 1 lb of Essential K® or Wholesome Blends™ Balancer daily. During EPM recovery, we would add an additional 1 lb (2 lb per day total) on top of this for an extra boost of nutrients. If your horse is on a full intake feed (one designed to be fed at 4+ lb per day), we would add 1 additional lb of Essential K® or Wholesome Blends™ Balancer on top of their regular feed.

Additionally, Natural Remedy™ is a DHA Omega 3 Fatty Acid supplement that can be combined with treatment for its natural inflammatory properties.

After EPM treatment, the focus should remain on providing a balanced diet that meets the horse’s needs for vitamins, minerals and amino acids.

Nicole Rambo, Ph.D.