Root Causes of EPM

Let me start off by saying- THIS IS NOT VETERINARY ADVICE.

I often come across horses with low-grade EPM or who had already been through veterinary treatment only to keep relapsing. As an osteopath, I am not licensed to diagnose; however, we are trained to identify signs of EPM because it is a contraindication to some manual therapy. EPM is a protozoal infection in horses. There’s lots of resources where you can find details on EPM- this article focuses on the osteopathic implications and prevention strategies. In osteopathy, we are always aiming to address root causes, and a protozoal infection may seem like it would be it's own root cause- however there is more to the story. For instance- do you ever wonder why some people tend to attract more mosquito bites than others? Read on to see why!

Why EPM is a contraindication to Manual Therapy

The protozoa like to eat a certain protein that’s found in the spinal tract which causes laxity in the spine-so spinal manipulations could be damaging. EPM also causes wasting of postural muscles- you see poor top lines, poor gluteal muscles, hollow necks, hollowness around the eyes and instability. It’s not that they’re necessarily “neurologic” or ataxic, but they have a proprioceptive deficit: meaning they don’t really know where to their feet are, which makes some dangerous to ride and a potential danger to themselves and others.

Common Factors in Horses with EPM

As an observer, I have identified commonalities in the histories of horses with EPM who have been diagnosed by veterinarians but still struggle to remain symptom free. In my opinion, there are three factors that cause horses be more prone to EPM infections. If we accept the newer research that tells us that it is most likely spread by birds, not just possums, that means that exposure is everywhere. It is also theorized that the protozoa lives in the gut of horses without causing symptoms. So why does one horse at a property show symptoms and not another?

1. Lack of consistent and thorough deworming:

Other parasites, specifically large strongyles, are present and putting a burden on the immune system and allowing the door to open to a more pernicious pathogen, which is the protozoa EPM. They also create the conditions necessary for the protozoa to be able to migrate out of the intestinal tract and cross into the nervous system. Ulcers also create the necessary "holes" in the stomach for the protozoa to cross.

2. Lack of vitamin E supplementation:

Most horses in California are not on pasture and our forage just doesn’t have sufficient amount of vitamin E in it. There’s a body of research out of UC Davis on the topic. If they’re not on pasture: fresh green grass, they need to be on a vitamin E supplement. Natural and liquid is best, you want to avoid soy as a vitamin E source.

3. Stress, Trauma or Body Pain

Stress raises your cortisol levels which has its own cascade of dysfunction. One effect of heightened cortisol is a lowered immune response. Horses that have some type of situational stress and/or body pain (pullback injuries, sacroiliac dysfunction, or any other type of ongoing long-term body pain that has not been sufficiently addressed, teeth, feet imbalances, saddle fit) anything that’s going to cause that horse discomfort is ultimately going to put a strain on the body and on the nervous system. Stress makes the body acidic and leads to the rise in cortisol - which lowers their immune system creating an environment friendly to pathogens.

Prevention Strategies

This is why most anti-protozoal treatments fall short of eradicating EPM- they are missing the other key components of the healing process- supporting the immune system, tackling the other parasites and addressing the sources of stress in that horse's life- for a sufficient enough time for the body to catch up. It is time consuming and expensive to treat EPM- therefore we should focus our efforts on prevention.

Your best defense is a good offense: deworm consistently by weight, sufficient enough to not create resistance, supplement with vitamin E and balanced minerals, forage-based diet, regular work on body, teeth, feet, saddle fittings. This is not a replacement for veterinary medicine, but good horse keeping and management will save you money in the long run by avoiding major illness.

As for those pesky mosquitos- researchers have discovered that people with higher cortisol attract more mosquito bites. As stated above, cortisol- the stress hormone- changes your immune system, pH, liver function, and contributes to insulin resistance among other things. Making you/your animal a prime target for parasites (including worms, fleas, ticks, mosquitos, protozoa, viruses) to thrive. Having a solid plan to help our animals adapt to human conditions and manage stress, inflammation, address body issues, feeding an optimal diet and encouraging natural herd behaviors go a long way.

If you would like to read more about the osteopathic perspective on EPM, I encourage you to visit Dr. LuAnn Groves site and articles. https://thewholehorse.com/treating-equine-protozoal-myeloencephalitis-epm/