My horse has EPM, now what?

What in the world is EPM?

EPM stands for Equine Protozoal Myeloencephalitis. This is a nasty little neurologic disease, but usually very manageable. Depending on the stage the horse is diagnosed, and any other diseases they may have, a horse can recover and have a normal life.

What causes EPM?

The cause of this tricky neurologic disease is a protozoa called Sarcocystis neurona. Occasionally Neospora hughesi, another protozoa will also cause the same clinical signs. Protozoa are large microbes. An example of one that might sound more familiar is Giardia, also a protozoan parasite.

Where so horses come into contact with these protozoa?

We do know for a fact that horses are exposed to these protozoa much more frequently than we actually see them develop disease. The most well researched method of exposure is that of horses exposed to urine or feces of the opossum. While there is speculation that other rodent or even feline types may also serve as intermediate hosts for the EPM protozoa, this has not been definitively proven.

Sometimes this exposure is direct and obvious. Something as crude as a dead opossum in a horse’s water trough would mean definitive exposure. However, sometimes the exposure is vague and undetermined until a later date. Even loads of hay brought in from another state, or drinking contaminated water at a pit stop traveling across the country.

REMEMBER: Exposure does NOT equal disease

What are the clinical signs?

Here is a list – again not all inclusive, and most certainly NOT a diagnosis just because your horse displays these signs. Just a list that I have pout together from my personal experience. Some horses with EPM have all of these signs, some have non of these signs!

  • Ataxia (asymmetrical)
    • Wobbly/ wandering/ abnormal control gait
  • Muscle atrophy
    • Usually a later stage issue
  • Nervousness/ anxious
  • Signs of ulcers
  • Unpredictable behavior
    • Spooking at odd things
    • Setting back when they didn’t use to
    • Bucking when they didn’t use to
  • Stumbling
  • Weakness
  • Sensitivity at the pole
  • Head tilt even (rare in my opinion)
a brown horse and a gray horse grazing on hay

How is EPM diagnosed?

The most definitive diagnosis is made with a paired blood and spinal fluid sample sent to a lab. Often times, especially in a field setting, we will just send in a serum (blood) sample and pair that result with our clinical exam/suspicion. This is something I have fortunately had a lot of experience with. From top level performance horses, to the backyard rescue horse, I have tested them all.

Now that my horse is diagnosed, what do I do now?

I am so glad you asked! This is the million dollar question these days. Every veterinarian seems to have their own treatment formula. I definitely have my favorites, however I try my best to cater the treatment to the goals, and to what is possible for the owner financially, as well as practically administering the treatments. I have seen results with just about every treatment variation out there.

Right now I have had great results taking pieces of the protocols from Dr. Groves in Texas. She has spent a lot of time in Arizona, and is now in Texas. She has a great practice there with LOTS of experience with EPM, also from an integrative medicine perspective. Right up my alley!

Like I said, I have to take several factors into consideration when choosing a treatment plan for each horse. I don’t think I have EVER treated any two horses the same. This is merely because of the individual situations presented in each case. I have however treated over a hundred horses for EPM. I am going to list my protocols here, understand that I do not recommend implementing any of these protocols, prescription or not, without first consulting your veterinarian.

If you would like to schedule a phone consultation to go over your individual horse and situation I am happy to do that as well. However, an in person exam and a blood test would be the most ideal. EPM is NOT the only disease that causes neurologic/ behavior changes in horses.

picture of a brown horse looking over a fence


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MY Favorite – No Limitations Treatment Option

  • Panacur Powerpac
    • Not applicable in all cases!
    • Makes sure that the immune system is not fighting a heavy parasite load concurrently
  • Sefacon treatment
    • 10 day treatment
  • Epic Liquid – 4 months minimum
  • Karbo Pellets – 4 months minimum
  • Vitamin E supplementation (must be the natural d-α-tocopherol)
    • I like the Elevate or the HealthE
      • Follow instructions for maintenance on tubs
    • I also really like ExcelEq Camelina Oil for vitamin E as well as Omega anti-inflammatory support, but there is really not enough Vitamin E in this supplement if your horse needs extra nervous system support
  • Nervous system anti-inflammatory/ support
    • My absolute favorite hands down is Spine and Nerve from
    • Follow instructions on the tub
    • If you would like a little discount and send a small commission my way (at no additional cost to you!) use my code LVS at checkout
  • Ozone therapy (either administered at home or by myself or another ozone therapy trained individual)
    • A series of 3 treatments week 1, 2 treatments week 2, and then 1 treatment a week for 2 weeks in a row and then 1 treatment once a month thereafter/ as needed
  • Equiscope therapy
    • Again this is something I provide or there are others that also do a good job, just call us for references.
    • I have seen and heard from others that the fastest recovery from neurologic signs (abnormal gain) have occurred after several treatments of Equiscope in conjunction with other treatments
    • A series of 3 treatments week 1, 2 treatments week 2, and then 1 treatment a week for 2 weeks in a row and then 1 treatment once a month thereafter/ as needed

The Marquis Standard Treatment #1

The Protazil Standard Treatment #2

The ReBalance Standard Treatment #3

Compounded Medication Option (Mix and Match supportive therapies but different anti-protozoal)

Orogin Anti-Protozoal Option

What are some other things you can do for your neurologic horse?

Doesn’t every one love a little physical therapy? A little PT can go a long way. Strengthening and training the muscles to help support the horse can help to offset the neurologic deficits.

Lateral tail pulls are a great exercise for the hind end. I recommend these for all kinds of horses with varying issues. They are great for supporting the stifles as well as overall hind end strength in our older horses.

I prescribe this protocol: 10 times 10 seconds on both sides, 3 times a week

Backing is also a great hind end exercise. Whether under saddle or on the ground, back your horse for several strides every day. Variations of this are also helpful. Backing up and down small hills, backing over logs, backing in an arc/ circle. Please keep in mind you will do all of these depending on your horse’s own ability. I ALWAYS caution owners about riding a neurologic horse. There is a fine line between still safe, and definitely not safe. Ultimately this is at the owners discretion.

The last exercise I like to recommend for strengthening the hind end is leg lifts. They are exactly what they sound like. Taking care to get yourself in a strong position, lift your horses hind foot as if to clean it out. Then, supporting yourself and your horse’s limb, gently lean into your horse. This forces that same contraction and balance in the opposite limb that we witnessed in the tail pulls.

I hope this was helpful!

For more information/ scientific papers on EPM look at these links below:


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