Horse Health Q&A: EPM - Symptoms, Prevention Tips & Natural Support Solutions

Horse Health Q&A: EPM - Symptoms, Prevention Tips & Natural Support Solutions
For the horse owner, EPM or Equine Protozoal Myeloencephalitis is one of the most frightening diseases. There are medical treatments, but there is no vaccine for prevention. Unless EPM is caught in the very early stages, the chances of a full recovery are not good - and the disease can be fatal. Read on to learn more about prevention, natural support, and signs and symptoms.

What is EPM?

EPM - or Equine Protozoal Myeloencephalitis - is a devastating disease caused by protozoa that create or leave lesions on the spinal column all the way to the brain. The lesions cause neurological damage, which can leave horses severely disabled and may result in death. It is this neurological damage that can cause the various symptoms of EPM. 

EPM can affect horses, donkeys, mules and minis. It is not contagious from one horse to another like a virus is. Once they have it, they are the end host to the protoza.

The diagnoses of EPM can be difficult at best because the symptoms of EPM can look like other neurological diseases - such as Herpes, West Nile, Viral Encephalitis, and Wobblers. Symptoms can start with something as 'insignificant' as:

  • Stumbling
  • Sweating
  • Mild laminitis
Too often, the symptoms can be blamed on other problems/health issues and a proper diagnosis is missed.

How Do Horses Get EPM? Is there Another Way Besides Ingesting Opossum Feces?

When a horse comes in contact with - or ingests - the feces/manure from a “vector”, usually a opossum, that horse is now a carrier of the protozoa for EPM. The feces of opossums can/may contain sporocysts – which are cysts that contain spores that can reproduce asexually. Horses can ingest these sporocysts with feed, hay, grass or water contaminated with opossum feces.

Some have thought that raccoons, sea otters (who comes in contact with sea otters?), and other small animals may have the protozoa, but that has in fact never been proven. As of now, it has only been a theory.

EPM Signs & Symptoms – What Should I Look For?

One of the difficulties with diagnosing EPM is that it can look like many other neurological diseases. Symptoms vary between horses so not all horses will have all the symptoms. Some symptoms may include:

  • Loss of coordination
  • Muscle atrophy on the body, especially over the hind end and even in the muscles in the face
  • Difficulty swallowing and sometimes chewing
  • Sore back
  • Stumbling
  • Locking of the stifle joint, lameness issue up to laminitis
  • Weakness, lack of energy
  • Drooping eyelid
  • Head tilt or head shaking
  • Unexplained sweating
(The above is only an example of the most common symptoms, but there can be others.)
Video - EPM Basics for Owners

What Are the Effects I Might Notice at Onset?

If a horse is mildly affected you may only notice:

  • Weakness
  • Stumbling
  • Slight lameness
  • A stifle issue
  • That your horse has no energy
If left untreated the horse may be unable to stand or swallow (which can be confused with Wobblers) and death can occur.

What Age Group of Horses Are Most Susceptible?

Horses of any age, sex or breed can develop EPM. However younger horses, between the ages of 1 and 5 and horses who are transported frequently seem to be at greater risk. Risk is thought to be greater in the autumn months than at other times of the year.

This may be because opossums are looking for warm winter homes in and around stables as cooler weather approaches. But a horse can contract EPM any time of the year.

Could My Horse Get EPM?

Any horse living in an area that has a lot of opossums - or any horse that may eat hay brought in from an area known to have a large population of opossums - can get EPM.

I know firsthand. My horse, Destinee Rose, got EPM in the early 2000s - from a load of hay out of Colorado. Back then, no one knew what she had. There were no real tests, no meds to speak of - just a knowledgeable holistic/homeopathic vet and myself treating her.   It’s a journey back to health for your horse, especially if caught early and provided with the best nutrition. 

There is so much more known now, and although there are vet meds these days they are very expensive and only 45-50% effective.  It was Destinee's journey with EPM that sparked my research into alternative support options - and the result is our EPM protocol that has proven successful for many. If you would like to read Destinee's EPM story, see: Destinee’s Journey.

What Can I Do to Help Prevent EPM?

  • Keep your horse's immune system boosted - I feel this is one of the most important things you can do. Feed probiotics, vitamin C and supplements and/or herbs to boost the immune system regularly. Give EPM Nosodes monthly as well.
  • Make your stable area unattractive to opossums - They carry the organism that causes this disease so it is important to make your stable area unattractive to these animals. Opossums will eat almost anything including dead animals (road kill), dog and cat food, or horse feed (bag feed, grains, oats, and even treats).
  • Keep food stores secure & clean spilled feed promptly - Keep grains in barrels with tight lids and bury any animal carcasses promptly. Humanely trap and remove opossums on your property - If opossums live on your property they should be humanely trapped and removed to help protect your horses from contamination. Fencing has been designed to prevent entrance of these animals and should be considered if opossums are a nuisance. Styles like diamond mesh wire link fence can make it difficult for opossums to climb, keeping them out of your pastures.
  • Dissuade opossums from living in your hay storage areas - If you rake up loose hay throw it out because you risk contaminating your horses hay with feces you may not see.

Will Chemical Wormers Kill the Protozoa?

Because of where the protozoa live, I do not believe that any of the chemical wormers on the market can treat or prevent EPM.

What About Treatment Options?

Because EPM can look like many other neurological disorders, a thorough veterinary examination is necessary. With quick diagnoses and proper medication most horses will recover from EPM; however, some permanent damage may exist.

Your vet will examine gait and movement, also any lameness issues, draw blood - and in some cases spinal fluid samples (if warranted and suspected). These samples will be sent to labs and examined for the protozoa.

Veterinary treatment includes antiprotozoal, antimicrobial and anti-inflammatory drugs, which in some cases must be administered by your veterinarian. Treatment may be lengthy and expensive and may be unsuccessful if the protozoa have left the spinal cord and brain stem badly damaged. High doses of Vitamin E have been used to help prevent the damage to the nerves.

Are there Alternative Therapies for My Horse if He/She Gets EPM?

Yes. There are alternative options for supporting a horse with EPM and helping to prevent EPM:

  • Homeopathic treatments are available and are easy to administer. They are a more natural approach to stopping the infestation and killing off the protozoa. Most horses do well with these and may need more than one treatment if it is a more advanced case i.e. muscle wasting, sweating et al.
  • Herbal support alternatives exist - which may not be as effective as the homeopathics - but offer good support at the onset and can be given in the fall to help prevent re-infestation of the protozoa. There are also herbal immune boosters to specifically support an overworked immune system.
  • EPM Nosodes can be given monthly to help prevent EPM.
  • Vitamin E in high doses can help prevent damage to the nerves.
Listen now to Jessica Lynn of Earth Song Ranch on Fox's Horse Talk Show with Louisa Barton discuss EPM in Horses - Holistic Options to Support Treatment & Build Immune System.
Earth Song Ranch's EPM support products were featured on Fox's The Horse Talk Show.

Natural EPM Support Kits

Earth Song Ranch, along with a holistic veterinarian, formulated an affordable natural homeopathic and herbal alternative to allopathic treatments to support horses that have been diagnosed with - or are suspected to have - EPM. We offer the Support Kit with and without an Immune Booster and Vitamins E & C, as many horse owners may already have Vitamin E & C on hand. All products are available for purchase separately as well.

Our EPM Support Kit includes:
  • EPM Homeopathic Kit - formulated by Dr. Gerald Wessner, DVM
  • EPM Herbal Support

EPM Complete Support Kit + Immune & Vitamins E & C includes the items above, along with:
  • Natural Vitamin E
  • Pure Vitamin C
  • Organic Herbal Immune Booster
The EPM Support Kit + Immune & Vitamins E & C provides the specific EPM support products we recommend to our clients - all at a $34.45 savings over purchasing individually. Although we cannot make claims, the synergistic effect of these products has produced great results for many horses - some showing visible signs of improvement in under 10 days.


The information provided here is for informational purposes only and is not intended as a substitute for advice from a veterinarian or other health care professional, and should not be used for diagnosis or treatment of any health problem or for prescription of any medication or other treatment. A health care professional should be consulted before starting any diet or supplementation program, before administering any medication, alternative, herbal blends et al or if your horse has a health problem. Do not discontinue any other medical treatments without first consulting your health care professional. © Copyright 2023. Earth Song Ranch. All rights reserved.

Questions? We're Here to Help

We know choosing the right natural supplement for your horse can seem daunting. Earth Song Ranch is dedicated to educating our customers because we want you to make the best choice for your horse and your unique needs.

You'll find a variety of information in our published articles and archived newsletters here on our site. But sometimes, you just need to talk a situation out. For those times, we offer private phone consultations.

EPM Prevention & Diet Consultations

We offer diet and nutritional consulting for those of you supporting or suspecting a horse with EPM - or looking to prevent EPM. Consultations are available in the following increments.

  • 30 minutes - $75
  • 60 minutes - $125

Go here to purchase a phone consultation.

Recommended Products

Natural EPM Support Kit for Horses with Homeopathics & Herbs

EPM Support Kit for Horses

Natural EPM Support for Horses with Homeopathics & Herbs

EPM Support Kit + Immune & Vitamins E & C

An Affordable, Complete EPM Approach with Homeopathics, Herbs, Immune Booster & Natural Vitamin E & Vitamin C
Complete EPM Approach with Homeopathics, Herbs, Immune Booster & Natural Vitamin E & Vitamin C for Horses

Customer Feedback

My experience with Earth Song started in 2020 with a two year old gelding that got infected with EPM. We started him on two months of medication with the standard EPM protocol from the vet. After two months, he was better but not a 100%, still not able to return to training.

We were referred to Earth Song Ranch and the herbal protocol for EPM that Jessica offers by our Equine Body Worker. We had no options at that point, so we decided to try the EPM protocol available from Earth Song Ranch, and the gelding started improving immediately. He is now back in training and has just got home from his first show! We are thrilled with the results and highly recommend Earth Song Ranch products.

—   Liz Remphrey, Remphrey Quarter Horses
"I just received my final box of the EPM supplement. I was talking to one of my friends who has used your company several times and she was explaining what an amazing person and company you have. EPM is such a scary disease and I’m so thankful for people like you and your company. In this crazy world, full of particularly grumpy people lately, I hope you know how much we value the service."
– Joanna
"I live in West Virginia and all seven of my horses came down with EPM. When the vet gave us the bad news, in the fall of 2016, well I phoned Jessica and we got them on the EPM kit right away and everyone seemed to resolve at their own pace, some quicker than others and they were all pretty much back to work and riding within just a couple of months. Then I had one that seemed to relapse and we decided to put them all on the Organic Immune Boost. I can tell you they have all been doing great, this has now been a years time, all are symptom free and we could not be happier to know there are natural alternatives for this horrible disease to turn to."
– PN, WV
"Two horses came to board with me, both with severe cases of EPM. One ended up passing away, the other we put on the EPM kit once we found out about it and the EPM Support herbs, in the beginning of September 2017. Within a week’s time this horse showed amazing signs of improvement, and continues to improve every day. We had amazing results for this gelding and we now know he will make it!"
– DM, OR
"Both of my horses came down with EPM in the summer of 2017, one was in training the other at home. We do not know how they came in contact with this, but I found the Earth Song Ranch website and sent for two EPM kits immediately. Each of the horses showed signs of improvement very quickly. The one at home seemed to take longer so we put that one on the EPM Herbal Support and he is now being ridden, at a walk, and seems to be doing better each day. Every fall I will make sure my horses are on the EPM Herbal Support to prevent this happening to them again, and I have also put them on the EPM Nosode to also prevent this horrible disease.

 - KM, MN
"My mare Ballis developed EPM last fall and with the guidance and help of Jessica – she recovered and I am back riding her. I truly believe the products I purchased and guidance Jessica gave me made it possible. Her kindness and vast knowledge of natural treatments is priceless! Thank you Jessica!"

 - Dawn L.

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About the Author

Jessica Lynn writes articles for various national and international horse publications. She is the owner of Earth Song Ranch, an herbal feed additive, pre/probiotic & herbal supplement manufacturer based in Southern California. As a life-long equestrian and professional animal nutritionist, homeopath, herbalist and animal intuitive, Jessica uses her knowledge to formulate herbal blends, probiotics and digestive enzymes for equine immune health. She has been involved in alternative health care, herbs, homeopathy, osteopathy and nutrition for animals and humans for over 6 decades.