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Horses and Equine Protozoal Myeloencephalitis (EPM)

Dr. Gray, if a horse is treated for a mild case of EPM, and the treatment is “successful”, can the horse make a full recovery or will it always be in their systems to where a possible recurrence could happen in the future. Thank you M.L.S.

Dear M.L.S.,

Equine Protozoal Myeloencephalitis (EPM) is a serious and potentially fatal neurologic disease of horses. It is also a disease near and dear to my heart, as two horses that I owned both developed it. My thoroughbred was treated, made a near 100% recovery, and hasn’t had a single relapse. My quarter horse/app was treated, did not quite recover his ability to canter, and relapsed so many times I lost count. So your question—full recovery or possible recurrence—is a good one.

According to Dr. Stephen Reed formerly of The Ohio State University College of Veterinary Medicine, the prognosis for horses with EPM seems to be similar regardless of the treatment used: 60 – 75% of horses improve on standard therapy. Unfortunately, less than 25% of affected horses return to their original function. While a number of medications have come on and off the market—and many continue to use the combination of trimethoprim/sulfa—there are currently only two FDA-approved medications for the treatment of EPM :Ponazuril (Marquis® and Diclazuril (Protazil).

The main concern, however, is the percentage of horses that relapse days, weeks or even months after treatment. Exactly why horses relapse is unclear, but there are three possible reasons: 1) the parasite that causes the disease, Sarcocystis neurona, came out of a form of hibernation within the horse’s body, 2) a small but persistent focus of infection was never completely killed off, or 3) the horse was re-exposed to the parasite.

To ensure your horse’s chances for success, I recommend a three-pronged approach. First, in addition to prescription medication listed above, work with your veterinarian to determine if anti-inflammatories such as phenylbutazone (“bute”) or flunixin meglumine (“Banamine”) should be used, if antioxidants such as Vitamin E, Selenium and others might support nervous tissue, and if the B-vitamin folic acid may prevent the deficiency sometimes created with treatment. Also consider natural ingredients that support the immune system and a healthy inflammatory response such as Omega 3 fatty acids and MSM.

Second, continue treatment for as long as your veterinarian advises or until tests on CSF (cerebrospinal fluid) come back negative. With your veterinarian’s recommendation, include physical therapy such as massage, hand walking, and specific stretches or exercises designed to strengthen and support affected parts of the body.

Third, follow the currently recommended suggestions for preventing EPM in your horse, such as keeping the primary host (the opossum) off your property, minimizing contamination of feed, water and grazing areas from intermediate hosts (cats, raccoons, skunks and armadillos), and reducing stress in your horse.

Lydia F. Gray, DVM, MA SmartPak Staff Veterinarian and Medical Director Dr. Lydia Gray has earned a Bachelor of Science in agriculture, a Doctor of Veterinary Medicine (DVM), and a Master of Arts focusing on interpersonal and organizational communication. After “retiring” from private practice, she put her experience and education to work as the American Association of Equine Practitioner’s first-ever Director of Owner Education. Dr. Gray continues to provide health and nutrition information to horse owners through her position at SmartPak, through publication in more than a dozen general and trade publications, and through presentations around the country. She is the very proud owner of a Trakehner named Newman that she actively competes with in dressage and combined driving. In addition to memberships in the USDF and USEF, Dr. Gray is also a member of the Illinois Dressage and Combined Training Association (IDCTA). She is a USDF “L” Program Graduate and is currently working on her Bronze Medal. Find Dr. Gray on Google+

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59 comments on “Horses and Equine Protozoal Myeloencephalitis (EPM)
  1. Lauren says: I started a blog about my horse and her fight with EPM. I plan to document before, during and after treatments… including images and videos. <3

  2. Hannah says:

    I took in a horse last year with EPM. He couldn’t walk straight and fell down almost once a day. The vet said he had probably had it for years after doing the appropriate tests. We went the non-traditional route of using herbal medicine (Qing Hao San) and within a month he was walking better. 4 months of treatment and we retested him to find no traces of EPM. He is now back to running around the pasture, bucking, rolling and is even under saddle. We go through the appropriate tests every few months and so far, so good. We even went on a 7 mile trail ride a few weeks ago. Perhaps these alternative ‘medicines’ should be looked into and talked about more.

    • Eileen says:

      Interesting treatment Hannah. Do you have more information as to dosages, etc? And where do you get Qing Hao San? Thanks!

      • Jess says:

        I’ve also had success with the Qing Hao, it’s also happens to be inexpensive. You can get it through most holistic vetrinary centers.

    • BETTY OTT says:


    • rika says:

      Where can I buy the herbal medicine (Qing Hao San) .My Horse got a relapse dueto my vet who didn’t give him further medication.He was fine till I didn’t give him his meds anymore.

    • Jenna says:

      Has anyone found out where to get Qing Hao San?

    • Tawny says:

      I know your post on EPM treatment is old but I was hoping you could tell me where you got the Qing Hao San from? I have asked several vets about it and none of them have ever heard of it or were of any assistance in knowing where I could get some. Also what dose were you giving? Thank you, Tawny

  3. Claire says:

    My horse had epm. He was treated, and the vets said he made a full recovery, and 6 months after the all clear to go back to work he fell down again. My vet recommend I never ride him again for our safety and he’s been a permanent pasture pet since he was 9. I had my new vet look at him when he got his shots and she said he had no signs of neurological issues and he was perfectly fine(he’s 14 now). This new diagnosis confuses me, along with how come he fell after they said he was fine?

    • Nathalie says:

      EPM isn’t a disease that just goes away forever. In fact, most horses have already been exposed to the cause – the protazoa. Horses who have been diagnosed with EPM are subject to recurrences of this disease – so it may come and go. As the owner, you have to be totally in tune with your horse – what’s normal or not for him, particularly his gait. Horses with EPM are often recommended to never be ridden because you can never really know when you’re going to get them past the point of being neurologically sound. Remember, dead nerves never ever grow back; nerves around them try to take up the slack. So for your horse, if you see anything funky, retest him. A test from Florida costs 38 dollars to do. We just paid less than 200 dollars for our test, results, vet visit, and a coggins – things are better now. He probably fell because he had a relapse of EPM. Be sure to keep his immune system strong. vitamin E supplementation helps, as do immune supplements. smart-Pak has tons of them – very affordable.

      • Nathalie says:

        By the way, even though a veterinarian cannot necessarily recommend a horse be ridden again, with care and rehabilitation and very VERY special attention paid to warning signs of recurrent EPM, many horses are able to go back to productive riding. Some don’t, but in our case we were lucky. My cutting horse I will never really trust to work in cutting again in competition, but he can be ridden working cattle, some light cutting, etc.

  4. Cynthia R Skidmore says:

    i have had two horses with epm. the 1st had to be put down due to the disease progressed to seizures and unable to move hindquarters and blindness. i am now in my 2nd battle with the best horse i have ever had the priviledge to own. we are on our 3rd relapse since 10/11. trying to support him with vitamin e and microlactin. also have been doing at home rehab and chiropractic and massage therapy. would like to donate him to a program studying this horrible disease for research. any suggestions? thank you for your response.

    • Nathalie says:

      Where are you located? Are you near Florida? Have you talked to your veterinarian about donation? With what are you treating?

  5. Karen says:

    My horse was just diagnosed with EPM. My vet believes we caught it early so I’m hoping for the best. Currently she’s being treated with Oroquin-10 and 2 bute for the duration of the treatment. I’m now giving her some vitamin E and Selenium with her vitamins. Can you recommend any specific supplements, vitamins, etc that I should keep her on after the 10 day treatment is over? I want to do anything I can to keep her healthy.

  6. Katie says:

    My first show horse who is now 13 was diagnosed with EPM about three months ago, he is currently on Marquis and lots of different vitamins to help with his immune system. He has no sense of where his front right leg is and is constantly dragging it around. We do turn him out and so far he is fine but is there anything else you would suggest? He was on marquis for the first month then switched to another medication which made him worse so we then switched back.

    • SmartPak SmartPak says:

      Hi Katie, our first recommendation is to make sure you continue working with your vet to monitor your horse’s progress and condition. In addition to the medication your vet is prescribing, you may want to ask him or her about adding Vitamin E to your horse’s diet. Many veterinarians suggest horses undergoing treatment for EPM be supplemented with Vitamin E to support their muscle and nervous tissue. We’ve included a link to our Natural Vitamin E below. Best of luck!

      Natural Vitamin E:

      • Linda D Lightfoot says:

        Is EPM contagious from one horse to anothe

        • SmartPak SmartPak says:

          Hi Linda, thanks for asking! EPM is not transferred from one horse to another. The organism that causes EPM is a protozoa called Sarcocystis neurona, and horses can be exposed to it when they come into contact with opossum feces, often when grazing. If you’re looking for additional information about EPM, check out the EPM section of our Equine Health Library: – Dr. Lydia Gray

  7. Guy French says:

    I have a 3 year old bucking horse stallion that came down with EPM. He went down today and can get him back up but only for about 5 minutes. He has no clue where his hindend is. I’m starting him on Marquis tomorrow. He is eating and drinking great. What are his chances for survival?

  8. Joanna says:

    I have four rescues and I often donate money food and computers to a local rescue. I just found out Joey my paint I have got at Christmas from a rescue has EPM, early stages the meds are between 700-1000 and I just don’t have it. I normally do pretty well but its been a tough 2012. I was told sometimes rescues will help. Please help me save Joey.

    • Cheri Barker says:

      I have a 25 year old TB that relapsed after 60 days and 90 days on SMZs.

      She was then treated with Oroquin 10 and is doing well. The Oroquon 10 in less than $200 and is a 10 day treatment. It was easier on her body then the SMZs as well. Good luck and best wishes to you and Joey.

    • Cayln says:

      Ask your vet about payment options. Most of the time your vet will work with you on the bills, as long as you pay them some money each month they should be willing to help you out. I was $7000 in and quite a few wrong diagnoses before one of my vets figured out that it was EPM causing my horse’s problems. Trust me when I say they’ll work with you.

  9. We have a beautiful saddle horse mare that we believe to have EPM. We are a rescue taking care of anywhere from 25 to 35 horses at any given time. She, Rabbit, was an owner surrender and very malnourished when we got her. She has the classic symptoms of falling down (when she first came in), very weak hind end with difficulty standing for farrier. She was evaluated by a vet 3 months ago and he suggested getting her back to health and very light round pen work to see if we could build up her hind end. She is looking a lot better and she hasn’t fallen in over 4 to 5 months. However, her hind in still isn’t right. He did not recommend the test since it’s about $250 and he said it’s not 100% anyway. His recommendation is to let her be a pasture ornament and use the $500 to $700 Marquis treatment which is what he recommended for her to be used to save other horses. I have always treated our rescues as if they were my own. If Rabbit were mine, I wouldn’t hesitate to do the treatment. However, there are so many unknowns with EPM. My question is this, if we decide not to do the treatment, will she get progressively worse? I’m trying to research this but there doesn’t seem to be any clear cut answers. Any help and advice you can give us will be greatly appreciated. Right now, she has quality of life and euthanasia isn’t an option. I just worry about letting her be a pasture pet and what the new owner will be facing.

    • SmartPak SmartPak says:

      Kudos for rescuing what sounds like a wonderful horse! Unfortunately, if EPM is actually the cause of your mare’s weakness, the longer it is left untreated the more likely she is to develop permanent, irreversible damage to her nervous system, which may prevent her from ever being safely adopted out. While watching and waiting is appropriate in some situations, getting a diagnosis and knowing for sure what you are dealing with is a better way to go in other situations. Fingers crossed for you, Dr. Lydia Gray.

    • Karen Olek says:

      Started conventional treatment on my horse, he was so ‘out of it’, I decided to try natural. Website, ‘for the love of the horse’, ordered their Chinese herbs for the immune system and Neurological issues. CJ was on it about 3 weeks when we noticed a beginning of improvement. Right side muscles slowly returning. Left side was much worse, leg hind leg turned out, CJ didn’t know he had this leg, dragged it. Just this past week he is walking a little better on it, putting weight on it. There were some days he was so bad, it was heartbreaking. But I knew it would get worse when the parasites were being cleared, then better. I plan on using TTouch to rehab him.

  10. Debra says:

    I have a 28 year old gelding that has been on protazil for 3 weeks he started to act normal after about 13 days ,even trotted to the barn to get his feed. Now this past Monday he is back to walking sideways and leaning to one side ,could he be having a relapse while on the medication?

    • SmartPak SmartPak says:

      Thanks for sharing your experience. We strongly encourage you to contact your veterinarian as soon as possible about this latest development, so that he or she can adjust the treatment regimen if necessary. With a condition as serious as EPM, it’s important to keep the treating vet apprised right away of all changes, good or bad, so that the most appropriate program for healing is prescribed. We’ve got our fingers crossed for you! – Dr. Lydia Gray

  11. Tenley Keller says:

    What are your thoughts on doing a follow up with Oroquin-10 after the 28 day Marquis treatment? My horse just finsished his 28 days and we want to know what to do next.

    • SmartPak SmartPak says:

      Thanks for your question. Oroquin-10 is not currently FDA-approved, although horses have been reported to improve with this treatment. We recommend working with your veterinarian to develop a continued treatment, physical therapy, and follow-up plan. – Dr. Lydia Gray

  12. Lyndie Carter says:

    We have an 8 year old Tb stallion with rear limb ataxia (left worse than right). He falls frequently but is able to get up with great difficulty. Our vet saw him 4 days ago and drew blood to send off. I assume for a western blot, he then went to a conference. These symptoms have worsened since he saw him. He didn’t want to start txt with rebalance until the test comes back Wednesday, but the horse may soon not be able to stand. I don’t know if he’s so far gone that tx is futile? He’s deteriorated so fast but he still eats and drinks. We’re also giving him bute 2 gms per day. What is your opinion?

    • SmartPak SmartPak says:

      We’re so sorry to hear that your horse is not doing well. We were just at this very same equine veterinary conference, the AAEP Convention, and there were some excellent educational presentations on EPM. Hopefully your veterinarian will be in touch soon with some treatment advice from some of the best minds in the country! – Dr. Lydia Gray

  13. Mary says:

    I have a horse that was diagnosed with EPM by the walking and pulling the tail method. Other than being off balance while doing this (crossing his legs in the back), and sometimes cross-cantering, behind…he has not shown any other signs of EPM. We now have him on a 30 day course of Oroquin. I will start him on the above suggested Vitamin E, sillinium & MSM. Do you think there is a good chance my horse will return to normal functioning work?

    • SmartPak SmartPak says:

      Hi Mary, thank you for your question. EPM is unique in that it can impact every horse differently. The truth is that the horse’s prognosis is dependent on a variety of factors, all of which your horse’s veterinarian will be able to evaluate. Your best bet is to sit down with your veterinarian and discuss your horse’s unique situation and what your horse’s career might look like based on his medical history. – Dr. Lydia Gray

  14. Sue Davis says:

    Hi Dr. Gray, I have a 7 y.o. Irish T.B.. He got very grumpy, sour, and started tripping a lot, especially behind. He’d catch his toe and then the hind end would sort of collapse. At first I thought it was stifles and did the whole estrone thing, then had my vet XRay/evaluate and injected his hocks. He improved slightly and then started to decline again. I had him tested for Lyme (positive titer) and also did the blood test for EPM (worthless I now know) and of course he has been exposed (1:1000). I’ve been treating him with Doxy for about 3 weeks now and the tripping has improved 70%, but the canter is not what it used to be and he still catches behind some. The canter used to be like a rocking horse and now it feels disunited somewhat, worse to the left. We’ve done some neurological testing and he’s not bad – just a coulple of little things that could/could not mean something. I don’t feel like this is the athletic bouncing ball that I bought 7 months ago, but I don’t want to treat for EPM unwarranted. I know the spinal tap is the answer, but I don’t think I can do that without the hospital runnning up quite a bill with lameness evaluations/blocks/neuro exams first. It would be more cost effective to just treat him. It’s convoluted with the positive Lyme titer too. Suggestions, opinions, ideas? Thanks for your help.
    Best Regards,
    Sue Davis

  15. Dee says:

    Hi Dr Gray, I have a triple registered 9 yr old mare who has been off and on short stepping behind since I bought her. We thought she just needed her hocks injected due to a previous injury and the fact she had been shown all over the country, Top 5 Pinto World and Top 10 at Congress in showmanship. Had her hock injected, no change, tried Prevacox, no change, Bute some change, not consistent. In Sept 14 under saddle all of a sudden she could hardly carry weight. Called local vet thinking Chiro adjustment only to have her do a Neuro exam and blood tests, came back positive for EPM. Whoa…did 30 days of Rebalance had a 95% change in her gaits (better) decided to do another 30 days to be sure, meanwhile I had a second vet do a 2nd opinion. Had her retested only to find the Rebalance is not actually killing the Protozoa. Started her on Origon yesterday for 10 days with recheck in 6 weeks. The test indicates she hasn’t had the infection long. I talked to Dr Ellison who said I should be able to start her back under saddle at day 5and she should be greatly improved. Other then the short stepping behind have not had the major neurological issues so many have had, no falling down,etc but I’m just a little leary of riding her now, just in case. Any thoughts?

  16. Elaine Appel says:

    I have a 6yo diagnosed with EPM 1:640 titer count…very little symptom….one episode of ataxia/depression. I did the 28 day Protazil. Last day of treatment was Jan 11. I started him on Vit E in form of Wheat Germ Oil from Health Food store. He is on 24/7 pasture turn-out. During winter months, I fed him some high quality compressed timothy/alfalfa/grass hay. He seems to be very normal with no symptoms. Planning to take to vet for re-check next week. 2 questions: is it possible for him to test negative?
    do I need to feed selenium for the vitamin E absorption?
    Thank you.

    • Carolyn says:

      Elaine Appel,
      really interested in your treatment, would you explain more about the episode of ataxia/depression you mentioned? My horse is also 6 and I’m midway through a treatment of Marquis. The vet gave him a 3/4 score (0-5 scale) for his symptoms and his titer count was 1:76. He was never falling down, just uncoordinated and wobbly looking from behind. He seems to be doing well, but I wonder what will happen next? Currently giving Vit E along with the Marquis.

  17. Debbie says:

    I have a 12 year old QH mare and an 18 year old QH gelding. Last summer, the mare tested positive for Lyme disease- not a titred test, but the pos or neg one. We treated her for Lyme with oxytetracyline IV for 2 weeks and also for an ulcer. Her original symptoms were headshaking and irritability. After treating for Lyme and the ulcer, she was fine. This summer, she was doing fine. Both horses were. Very light work, some trail riding for the mare.
    On August 6, 2015 I noticed the mare seemed to be ‘slipping her stifle’ on corners or turns, especially in deeper sand in the arena. She needed a trim anyway and when I brought her in, she seemed uncomfortable, shifting weight from side to side. I thought perhaps return to work was aggravating her hocks a bit and planned on giving her a few days off. The very next day, both horses developed a strange sweat pattern on their toplines. They were not sweating on chests or loins, just along the top of the neck, some under the mane, down the spine with some dry patches in it, looked like the top of both rumps had been sprinkled with water, and a very saturated area of sweat at the base of the tail on both horses.. wet enough to drip sweat onto tail hairs. This was present in both horses.
    I had just gotten new hay for the year, had moved hay around to make room for it, and after waiting a week or two, started mixing old hay with the new hay for the transition to prevent shocking them. We haven’t seen a possum on our property in 12 years, no raccoons, haven’t had cats in a few years now. Of course I keep all feed in varmint proof containers and never leave feed out, but we do have small turnouts with grass.
    I called the vet to come see my horses. There were no obvious neurological symptoms in either horse other than the strange sweating pattern especially if it was a hot day. They would sweat there even if not sweating in normal areas.
    Both horses were tested for EPM and Lyme. Here is where it gets weird.
    The gelding had no sign of EPM other than the sweating. He had a high test result- over 1200. The mare tested negative. Then the Lyme tests- neither horse tested in the percentiles the vets said they normally treat for. Just showing they’d had Lyme at some time.
    The vet said she was almost 100 % sure the mare had EPM and that if we sent more blood, it would probably be positive. The lab felt that the mare was a false negative and suggested a CSF test- I couldn’t afford all this if I was going to treat for EPM. We didn’t test for Lyme until we got the EPM results…
    Both horses were started on Tucoprim- the sulfa med- each at 4 scoops a day until the EPM results came in and the Marquis arrived. Treatment on Tucoprim was concurrent with Marquis for about 4 days to finish the supply. I purchased Smart Pak’s worming bridle to make sure we got all the Marquis into both horses each time.
    I am near the end of the first month of treatment on Marquis. The gelding is playing in the arena, looks great, and there are no noticable neurological symptoms at all. The sweating abated but so did our summer heat- and that’s what always brought it on. The mare is no longer slipping her stifle in hand in either direction, both horses brace against tail pull, no atrophy, no stumbling or anything else. The only problem the mare had was a very very occasional stumble we weren’t even sure was caused by anything but the uneven terrain of the ring, and the slipping stifles. The gelding had nothing. Both had the sweating. The mare still sweats on occasion, not the gelding.
    The mare is going to continue for another month on the Marquis. Actually, both will get Marquis for one extra week of the box, and then the mare will get the rest. I am about to begin very light groundwork with the mare. The gelding is retired anyway due to a healed fracture- sound on it thankfully, but not taking chances because it was in the fetlock and he does get sore if he plays too hard on it.
    Both horses have been getting Vitamin E and Selenium since the beginning, by the way. Also on pre and probiotics by Dynamite, free choice trace minerals, extruded feed with low starch- Senior Sentinal, we cleaned the barn out, couldn’t find any trace of possums, mowed the pastures, removed the clippings, raked off the arena, hay is fed from bags. I don’t know what else to do.
    We are going to discuss the prophylactic phase next and also whether or not the mare can be ridden again.
    My vet bill thus far has been substantial. And then there is the outside chance of Lyme disease with this being a very bad year for it here in CT. We can’t treat Lyme while treating for EPM because of possibility of laminitis or other reaction. Any thoughts, Dr Gray?

    • Debbie says:

      I wanted to clarify that I said above that nearing the end of the first mohth of treatment on Marquis the mare was no longer slipping her stifles in hand. I wanted to make clear that the only other thing we noted on the mare BEFORE diagnosis was a very occasional and slight stumble in the arena at the lope, something we didn’t associate with a problem, more to do with the terrain of the ring, or needing a trim. She hasn’t stumbled since we stopped all work and hasn’t had one episode of unsteady gait or staggering ever. I just wasn’t sure if Id been quite clear about that. Sorry if any confusion. Debbie.

    • SmartPak SmartPak says:

      Dear Debbie,
      It sounds like you and your horses have been through a lot! A second opinion is always a good idea and in complicated cases like these, you may want to ask your veterinarian to refer you to the nearest teaching hospital or referral center so that a board-certified specialist in internal medicine handles your case. They have additional training and expertise in getting to the bottom of tricky situations like you describe – that’s the route I would go with my own horse so that any money spent from here on out goes toward the correct diagnosis and treatment. Good luck in getting to the bottom of all this, Dr. Lydia Gray

  18. karen says:

    the ingredients in ivermectrin will also kill your horses and kills nerve endings resulting in some symptoms like epm.
    I am now using organic, herbs and other nutritional products with all my animals as well as myself, you need to wake up to the truth of the chemicals we r constantly being exposed to, our environment is dying and the parasites and other diseases have gain due to direct causes of unhealthy world!

  19. Blair says:

    My horse was diagnosed with EPM late last fall and responded really well to Protazil but it seems like he may be relapsing (pulled blood Wednesday so am waiting for the results).

    My question is if there is any maintenance medication/dose to keep him on to avoid relapsing again. He’s already on 8000IU/daily of Vitamin E (he also has shivers).

    • Joanne Boyd says:

      I have a shivers horse that has just been diagnosed with EPM. Can you tell me more about your experience with this situation. It is hard to tell what is shivers, what is EPM and what is caused for an injury.

    • Dana says:

      You might try Chinese herbal called Qing Hau San. Vets into holistic medicine carry it.

  20. Melissa West says:

    I have a mare who has EPM. She has been treated with the full dose of marquis and now the vet is trying good old standby Doxy. No improvement. He comes again this week and we are trying steroids at this point. She still can’t come out of her stall. It is heartbreaking. The steroids are pretty much the last option. Pretty sure she had it a long time without symptoms evolving. It is heartbreaking to say the least…Anything new out there anyone is aware of? Thanks..

    • Dotty says:

      I recommend talking with your vet about decoquinate. You can get a three-months supply in powder form from a compounding pharmacy for about $100. (It’s the same thing that’s in the Orogin product that some people in this thread talked about.) It’s an anti-protozoal that isn’t “approved” for EPM, but it works.

      I recommend testing for Lyme too. The more I learn, the more I find EPM and Lyme often go hand and hand. My horse keeps relapsing, so I’m just keeping him on the decoquinate indefinitely. At this point, what can it hurt?

      You can combine decoquinate with a drug called levimasole, which is also cheaper from a compounding pharmacy.

      Also recommend asking your vet about DMSO. If your horse will take it through an NG tube, it’s cheap and fights inflammation really well. Mine has to get it IV because he won’t take the NG tube, so it’s more expensive because it takes more time to administer. (You can try to give it orally but it tastes terrible.) Much safer than steroids.

      Also, there are some vets out there making that case that one or two months of Marquis or Ponazuril are just not enough—and it’s why so many horses relapse. If I ever have another horse diagnosed with EPM, I’ll be keeping him on meds for many months before I retest. And I would probably just keep the horse on decoquinate for the rest of its life. I think the vets need to seriously start looking at this like a chronic condition that requires life-long treatment.

  21. hannah says:

    I am looking to buy a horse that previously had EPM but is seeming to be better now. The ladies vet claims that it does not have a cure and his back leg feels like its always asleep. Apparently he is fine for trail riding for a rider under 200lbs. I way 110lbs. So i’m looking for opinions.

    • Dotty says:

      Based on my EPM nightmare from the last year, one where my horse’s symptoms are constantly recurring, I personally would not buy a horse whose “leg is constantly asleep.” I would also recommend asking yourself what you’d be willing to spend if you buy the horse and its EPM symptoms get worse. It is very expensive to treat. If you’ve ever seen full-blown EPM, the horse stumbles and leans, almost like it’s drunk. Also, if the horse you are considering is subtly favoring its other three legs because of the “numbness,” it could get supporting limb laminitis. That’s another topic not getting enough attention in chronic EPM horses.

  22. Dana says:

    My 24 yr old QH diagnosed with EPM in July. First signs in May. Mild hind end lameness, toe dragging 2/6 lameness scale. Slight atrophy on one side over hip and rump. Did two 28 day courses of Marquis. Plus bute, 10k IU vitamin E and Cosequin with MSM. Had balance issues but never fell over. In late October have started light Work under saddle. Have continued Vit e, Cosequin, and added QIng Hao San (3 weeks on this) which vet recommended and purchased from him. So far so good. If anyone wants info on this herbal I can put in touch with my vets office. Not sure it is working, but my boy is doing great right now.

    • Dana says:

      Update – my horse relapsed. Noticed signs of ataxia coming back in Dec. I contacted Pathogenes. Tested blood and they recommended Orogin (name has changed) $200 for 10 days treatment. Will keep you posted on results. He does have some muscle atrophy over left side of rump. My vet would like to do electroacupuncture. 4 sessions about 2-3 weeks apart. It is about $300 per session so I am reluctant as I am over $2K in expenses already for an aging horse. He my baby though so want to do best for him. Thoughts appreciated.

      • Mom2Four says:

        Dana, any update on your horse’s condition after doing the Orogin treatment? Also, did he eat the pills without issue or did you have to dose him or try another way to hide the taste?

        • Dana says:

          Unfortunately my horse did not improve with Orogin. Dr. Ellison thinks he that he likely has an immunity issue where the immune system attacks the nerves. He had done 2 rounds of Marquis prior and relapsed. He is on Dexametasone (a steroid) and Levamisole which are supposed to help boost his immune system. Also Vitamin E, Cosequin with MSM and Simply Flax. Not improving. We did one session of electroacupuncture about 3 weeks ago. I am not sure what to do next. I am just trying to keep my horse comfortable as I do not expect to ever ride him again. I cannot keep spending thousands of dollars on him though. My other horse is an aging pony with Cushings and other issues so between the two of them my vet and mediation/supplement bills are insane. If anyone has tried Novelle Research supplements let me know as that might be what I try next.

          • Dana says:

            Sorry forgot to answer the pill question. I crush all pill medications with a morter and pestle mix with some simply flax and water and use a syringe to give to my horse and pony. Both are experts at not eating meds so this works best for me.

  23. Shelly Moffatt says:

    Is EPM contagious from one horse to another? Should a stall be sterilized before using with another horse?

    • SmartPak SmartPak says:

      Hi Shelly,

      EPM is transmitted from horse to horse via opossums and other animals and not from direct contact from one horse to another. It’s important to keep wild animals away from your horse’s food and water sources to help reduce the risk of infection, however horses who are infected generally do not need to be quarantined. Of course, if you have any questions about an individual horse or situation, we’d recommend checking in with your veterinarian. Here’s another article on the topic that you may find helpful:

      – Dr. Lydia Gray

  24. shusaflyin says:

    I lost battle with my beauty in June … found hip atrophy in January but being in Colorado no one thouht of EPM … treated him for metabolic syndrome .. changed diet … atrophy continued .. found mild impingements in his neck but vet didn’t think that would get a neuro going … finally tested for EPM .. 76 % positive by US Davis .. did Marquis for 5 weeks .. kept thinking he would bounce back … left side worse . .. was dragging hin leg and when he stopped it would curl up behind other hind leg … awfull! .. he never bounced … on 6/14 I got up to find him frightened to death as he was loosing control of his hind hind .. his hips would just ‘fall over’ .. then he would trot off to try and stay up .. I called it ..I’ve cried for 4 weeks … 7 yr old QH .. the beauty of the world with world class training … so insidious .. this horse was never out of Arizona or Colorado .. so where did he get it

  25. shusaflyin says:

    I did find one vet ( holistic) that thinks there can be herpes issues with these EPM horses too … from the RHINO vacc .. too many … the protozoa was discovered 100 yrs ago … why in the last 15 to 20 years is the horse industry experiencing this burst of EPM …. I think their immune systems are being compromised … God only knows … Round up .. all Pesticdes .. too many vaccs … our poor horses are in these pastures and eating poison from our Ag Dept … you would think someone would wake up

  26. Sharon says:

    I have a 17 month old Arabian..that was healthy and playful one day and went down with no warning! She kept falling down, vet came out gave her shots checked her reflexes ,she lasted another day and a half and passed away ….I never left her and kept bathing her to kill the fever and kept giving her water! Still waiting for blood work on her, he is saying most likely West Nile! I’m wondering if it was EPM! Very concerned because I have eleven more horses! They got their shots but her because she would not let the vet near her so we put it off for a later date! Will never forgive myself if it was due to her not getting the shot!

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