EPM- Equine Protozoal Myeloencephalitis

[JaiteraMiniatures]

A vet in our area has "diagnosed" three horses with EPM. A friend of mine's horse was one of those three diagnosed. After talking to her I found out the vet only did a physical examination basically (tail pull, pressure points, and lameness exam). From what I've read about the disease it's rather rare, and VERY hard to diagnose (even with a blood test and spinal fluid test). Y'all are very knowledgable horse people and I'm just hoping to get more insight on this disease. My friend was told the only way to know for sure if a horse has it is to treat for it and see if it works...this just seems silly to me (not saying she's to blame obviously). I'm just wondering why other things weren't knocked out, because this horse showed NO major signs. And on the other side, if what I've read is wrong, and it is easy to diagnose, then why aren't more horses tested for it? It's potentially deadly, unpreventable, and the symptoms are hard to see in most horses.

PLEASE tell me all you know, and what you think about this situation (btw these are full sized horses I am refering to, incase anyone was wondering!) haha. THANKS!

 

[Sandy B]

I can tell you it has ended a lot of performance horse's careers. I know that it is supposedly carried by opossums, in their droppings and it gets in to the horse's water source and thats how they get it. It is a parasite that gets in the spine. There are some tests that vets do by physical exam and blood & spinal tests as you mention. I did think that those lab tests were pretty accurate though??? It is treated with a Marquis (sp?) and its a long treatment, one that is expensive and frequently needs to be repeated. Once a horse gets better I have heard of relapses. Many horses have dies due to failed treatment. I am sure by googling you can come up with more accurate info.

 

[Riverrose28]

I had a welsh/arab mare that I had to put down due to EPM, because it affected her spine and rear legs, and even with traction she couldn't support herself. From what I know it can mimic several other nurological deases,(Excuse the misspelled words). When my mare first exhibited symptoms it was as if she was drunk. This was several years ago just about the same time that west nile virus was discovered. Vet told me the same thing, no test available at that time, so we started treatment the medicine was liquid and It started with a p, can't remember the name. We treated her for seven days but she went downhill. Necropsy was performed and that is how I found out it was indeed EPM.

 

[markadoodle]

It is a neurological disease, I have had quite a few experiences with it... not good.

If left untreated the horse may be unable to stand or swallow and death can occur.

I'll reply later to edit this and put on all the info I know, I have pages and pages on it.. Here is a short bit.

Symptoms:

One of the difficulties with diagnosing EPM is that it can look like many other neurological diseases. Symptoms vary between horses. Some symptoms may include:

• loss of coordination
• muscle atrophy
• difficultly swallowing
• sore back
• stumbling
• roaring
• locking of the stifle
• weakness
• drooping eyelid
• head tilt

Careful examination, blood or spinal fluid tests must be done to rule out diseases like West Nile or rabies.

 

​

 

[targetsmom]

I knew a horse in a boarding barn several years ago that got it and died from it. The first sign (that I know of, because I saw it) was some pawing. Not sure how it was diagnosed or treated, but it was felt to come from contamination of the feed from a animal (opossum maybe). But ALL he horses in the barn got the same feed (which was in a feed cart and could have easily gotten contaminated) and only one got EPM. Very, very, scary....

I agree with Sandy - I would Google it for more info!

 

[kaykay]

My friend is dealing with this now and maybe she will come post.

I did read there is a new test that is very accurate

epm test

Im not a fan of not testing and treating. The thing is that it mimics so many other diseases. If the vet is wrong, you treated for the wrong disease for months. You cannot go back and test once you treat them.

I know she was also saying (and i have read before) that a horse can carry EPM for years and not break out with it until something stresses them. I do think treatments are getting better and more effective so that is a great thing

 

[JaiteraMiniatures]

I read up a lot on it last night since this is the third horse, and it apparently being a rather uncommon disease. From what I've read a horse can eat contaminated hay, feed, or water (it comes from a protoza in opossum poo, and somewhere it said birds too). It's unprevtable and there is no vaccine at this time. A horse can be contaminated with what CAUSES EPM but NOT have EPM. Only when the it crosses the blood-brain barrier does it become EPM. A horse can carry it for its whole life and never actually get EPM. Usually some sort of stressor causes the disease to be set off. I've read several websites saying only 0.05% of horses actually have the disease...it is VERY often misdiagnosed, because it's very simular in symptoms to other neorological diseases. A blood test can be taken, but a lot of times a horse tests postitive, because they CARRY the protoza but DO NOT have EPM. Most places say a spinal fluid exam is more effective, but it is still NOT perfect. A blodd exam is about 50% accurate and a spinal fluid exam is about 80% accurate. There are some other more complicated tests, but I'm not sure how to explain them.

From what I understand they are more accurate, but you have to take your horse to a special place for them to be done and they're probably rather expensive.

I also DO NOT agree with the test and see philosphy. That's spending time treating something the horse may not have. I also think that treating a horse for something they may not have builds up a resistance to drugs. I hope my friends horse shows improvement, but even the vet told her his was so slight she would probably not see any major changes (he's only getting one treatment and then some sort of supplement in his feed).

My MAIN consern is he did not do a blood test. That could have knocked EPM right out, if he didn't have it in his blood there's no way he has the disease. He could have also knocked out West Nile, Rabies, and other diseases that are accurately tested.

This disease is a little scary, but I'm just not sure what approach I would take. I think if my horse was having some slight neorlogical symptoms I would test for the other testable diseases and if he didn't have those, tested positive on a blood test for EPM, then I think I'd go ahead and treat for EPM and see if it works. I just think it would be hard for me to treat my horse for something I wasn't POSITIVE he had. Only after knocking out other possibilites could I even begin to think of treating it...basically a last resort NOT a first.

What do you guys think?

 

[OhHorsePee]

My mare has EPM. For ease I will paste what I posted on another site below. Even though the new test is better there are no tests that are 100% accurate. The below statement was taken from Blood Horse

"The newest test, the SAG-1 ELISA, has shown mixed results, depending on the study and population tested. The test looks for the presence of a particular surface protein of S. neurona, as its name implies, but not all strains express this particular protein. Thus, the test might be effective in detecting strains that express the SAG-1 protein, but it misses strains that do not. Therefore, false negative results (misdiagnosing horses that truly have EPM as being free of the disease) are common."

The trouble with the tests are there are false negatives AND false positives.

A lot of people that I have spoken with automatically start to blame the hay that was being fed. Hay can be one of the culprits as opossums and coons like to bed in them and defecate on the hay but there are other ways your horses/ponies are exposed to the parasite. We have a fence line that is the farmer's behind us (whom actually says it is ok for us to tear out) that has heavy brush, weeds, old hay bales and trees. A creek is only feet away from there. Places critters like to inhabit. If a coon or opossum climbs the fence and gets in your pasture and defecates your horses/ponies can graze in the effected area and pick up the parasite. If you are at a show and stalled where a opossum or coon who is infected with the parasite has defecated and not cleaned out your horse or pony can pick up the parasite. If you bed with straw or shavings that has been defecated on by an infected coon or opossum and your horse or pony eats the BM... well, I think you get the idea. Fact is life isn't cut and dry. Sometimes you need to step back and consider the whole picture.

On December 31st Baby started to act as though she had injured her right hip. I called the vet and he examined her. Nothing else was off about her. He even commented on how nice she looked. Since we had snow and ice on the ground it was assumed by all that she had hurt it. She had no fever or other signs that would make you go hmmm. We gave her Banamine for a couple of days and she was doing great. Then, after a while, Baby started being off on her gait. Called out the farrier. She did have a small bruise on her hoof but even her ambulation was perfect by the time he got here. No one else was seeing what I was. Baby would have a change and then she would be ok by the time someone else saw her. She had more good days than off days and sometimes she would be off for just a few minutes or an hour. It was just weird. At one point I may have even considered founder was a part of this but something kept telling me that this was something more. I kept thinking that every symptom came from a bigger picture. Vet came back out. Baby looked great and was playing out in the field. Strutting her stuff. These type of episodes kept happening since December 31st. Baby had her worse episode a couple of weeks ago. Her gait was way off, she was favoring her right hip and her hooves seemed like they grew at an astronomical rate in just a couple of weeks. Baby was also off with her grub. The vet was going to come out and my farrier was coming also. My farrier could not believe what he saw. In just a few weeks Baby had an inch of growth on her hooves. I asked about founder and he said no way. He showed me the rings in her hooves and said he thought something else was going on and even mentioned EPM. By the time the vet got here Baby was even holding her head in the corner and acting way off. At that time she was so classic EPM with her symptoms it was the first thing the vet said. She just breaks my heart! She had a hard time getting up this morning. Baby has started her medicine and we are all hopeful for her. The vets are giving her a good prognosis. She may just end up with a small drag on her right hoof. Please think good thoughts for Baby! I can't begin to explain what Baby means to me. I just love her!

 

[Michelle@wescofarms]

We had a horse in ICU with 'EPM' type symptoms. The vets were sure that was what it was, but tested for other things (spinal and blood test). His symptoms were loss of coordination of his back legs and flaccid tail. He never lost his front end, no fever, great appetite, he actually got lose one day while they were cleaning his stall and went in search of mares (28" stallion).

The tests confirmed it was WNV, he just didn't have the 'classic' WNV symptoms.

Definitely get a test before treating.

 

[JaiteraMiniatures]

My mare has EPM. For ease I will paste what I posted on another site below. Even though the new test is better there are no tests that are 100% accurate. The below statement was taken from Blood Horse

"The newest test, the SAG-1 ELISA, has shown mixed results, depending on the study and population tested. The test looks for the presence of a particular surface protein of S. neurona, as its name implies, but not all strains express this particular protein. Thus, the test might be effective in detecting strains that express the SAG-1 protein, but it misses strains that do not. Therefore, false negative results (misdiagnosing horses that truly have EPM as being free of the disease) are common."

The trouble with the tests are there are false negatives AND false positives.

A lot of people that I have spoken with automatically start to blame the hay that was being fed. Hay can be one of the culprits as opossums and coons like to bed in them and defecate on the hay but there are other ways your horses/ponies are exposed to the parasite. We have a fence line that is the farmer's behind us (whom actually says it is ok for us to tear out) that has heavy brush, weeds, old hay bales and trees. A creek is only feet away from there. Places critters like to inhabit. If a coon or opossum climbs the fence and gets in your pasture and defecates your horses/ponies can graze in the effected area and pick up the parasite. If you are at a show and stalled where a opossum or coon who is infected with the parasite has defecated and not cleaned out your horse or pony can pick up the parasite. If you bed with straw or shavings that has been defecated on by an infected coon or opossum and your horse or pony eats the BM... well, I think you get the idea. Fact is life isn't cut and dry. Sometimes you need to step back and consider the whole picture.

On December 31st Baby started to act as though she had injured her right hip. I called the vet and he examined her. Nothing else was off about her. He even commented on how nice she looked. Since we had snow and ice on the ground it was assumed by all that she had hurt it. She had no fever or other signs that would make you go hmmm. We gave her Banamine for a couple of days and she was doing great. Then, after a while, Baby started being off on her gait. Called out the farrier. She did have a small bruise on her hoof but even her ambulation was perfect by the time he got here. No one else was seeing what I was. Baby would have a change and then she would be ok by the time someone else saw her. She had more good days than off days and sometimes she would be off for just a few minutes or an hour. It was just weird. At one point I may have even considered founder was a part of this but something kept telling me that this was something more. I kept thinking that every symptom came from a bigger picture. Vet came back out. Baby looked great and was playing out in the field. Strutting her stuff. These type of episodes kept happening since December 31st. Baby had her worse episode a couple of weeks ago. Her gait was way off, she was favoring her right hip and her hooves seemed like they grew at an astronomical rate in just a couple of weeks. Baby was also off with her grub. The vet was going to come out and my farrier was coming also. My farrier could not believe what he saw. In just a few weeks Baby had an inch of growth on her hooves. I asked about founder and he said no way. He showed me the rings in her hooves and said he thought something else was going on and even mentioned EPM. By the time the vet got here Baby was even holding her head in the corner and acting way off. At that time she was so classic EPM with her symptoms it was the first thing the vet said. She just breaks my heart! She had a hard time getting up this morning. Baby has started her medicine and we are all hopeful for her. The vets are giving her a good prognosis. She may just end up with a small drag on her right hoof. Please think good thoughts for Baby! I can't begin to explain what Baby means to me. I just love her!

I am so very sorry for your mare! A gelding at my barn (a different horse) was having wacky personalitiy changes and some coordnation problems and the vet diagnosed him with EPM. He was treated for about a month or two and he's doing GREAT!! You can see the muscle atrophy in his butt when you stand behind him, but he's doing wonderfully

He's being ridden and he's only got one personality now instead of 5 LOL xD I hope the same happens for your mare.

Thanks for the info too!

 

[JaiteraMiniatures]

We had a horse in ICU with 'EPM' type symptoms. The vets were sure that was what it was, but tested for other things (spinal and blood test). His symptoms were loss of coordination of his back legs and flaccid tail. He never lost his front end, no fever, great appetite, he actually got lose one day while they were cleaning his stall and went in search of mares (28" stallion).

The tests confirmed it was WNV, he just didn't have the 'classic' WNV symptoms.

Definitely get a test before treating.

Wow, thanks for saying this. I'll definitely keep this in mind.

 

[Jean_B]

I had a mare that had EPM which was likely from eating some grass that an oppossum or armadillo had peed on. Within 3 days she went from a robust, healthy animal to one that was dropping weight like crazy, and very uncoordinated and wobbly...almost falling over sideways at times. At first I thought maybe she had rabies because she especially has trouble controlling her rear legs, but she did not have any personality change and was her usual friendly self.

The vets agreed that the best course of action was to immediately put her on the generic treatment for EPM - and that if she responded to it, that was my diagnosis (sorry, can't remember the product name but I can tell you that the generic cost about 1/3 as much as the name brand stuff). It was a powder that I mixed with pancake syrup that I syringed into her mouth. She LOVED that! She did immediately respond, but I had to keep her on the treatment 2 times a day for 6 months before she totally got her coordination back. The tests are VERY expensive and take about a week to get a diagnosis. The vet said that if I had waited another day or two she would have died, and as poorly as she looked, I'm sure she would have, so I'm glad I immediately put her on the EPM medicine.

She has fully recovered and has produced 3 NICE foals since then.

 

[JaiteraMiniatures]

I had a mare that had EPM which was likely from eating some grass that an oppossum or armadillo had peed on. Within 3 days she went from a robust, healthy animal to one that was dropping weight like crazy, and very uncoordinated and wobbly...almost falling over sideways at times. At first I thought maybe she had rabies because she especially has trouble controlling her rear legs, but she did not have any personality change and was her usual friendly self.

The vets agreed that the best course of action was to immediately put her on the generic treatment for EPM - and that if she responded to it, that was my diagnosis (sorry, can't remember the product name but I can tell you that the generic cost about 1/3 as much as the name brand stuff). It was a powder that I mixed with pancake syrup that I syringed into her mouth. She LOVED that! She did immediately respond, but I had to keep her on the treatment 2 times a day for 6 months before she totally got her coordination back. The tests are VERY expensive and take about a week to get a diagnosis. The vet said that if I had waited another day or two she would have died, and as poorly as she looked, I'm sure she would have, so I'm glad I immediately put her on the EPM medicine.

She has fully recovered and has produced 3 NICE foals since then.

That's crazy how quickly your mare showed major symptoms. I guess every horse reacts differently...none of the horses I know personally have had such serious symptoms. It's a good thing you treated it as quickly as you did. I'm glad your mare is happy and healthy now

 

[Riverrose28]

I read in Equess magizine that there is a test for EPM now, but since a horse can be exposed but not have syptoms it is not realiable. It can give a false positive. Also on the subject of rabies, I worked for a small animal vet for over 20 years, but did retire in 2001, unless they have developed some thing new the only way to test for this is to put the animal down and necropsy the brain to confirm rabies. Of course times have changed, maybe there is a new test. If someone knows of one please let me know.

 

[JaiteraMiniatures]

I read in Equess magizine that there is a test for EPM now, but since a horse can be exposed but not have syptoms it is not realiable. It can give a false positive. Also on the subject of rabies, I worked for a small animal vet for over 20 years, but did retire in 2001, unless they have developed some thing new the only way to test for this is to put the animal down and necropsy the brain to confirm rabies. Of course times have changed, maybe there is a new test. If someone knows of one please let me know.

Im pretty sure you're right about the rabies. I don't know why I didn't think about that before I wrote it down. haha. You can test for WNV and EHM which can show simular signs as EPM...sorry aout that xD

 

[Matt73]

I'm pretty sure it's only the feces of possums (and other animals such as raccoons) that can pass EPM (not the urine). Someone on here was happily feeding possums on her property and I alerted her to this danger. It's not that rare. We have the odd possum come on the property and I find its feces on the driveway. Hence, I keep my barn (and all food that would tempt the nasty things) locked up at night.

 

[Nathan Luszcz]

Takes a spinal tap to definitively diagnose. The blood test is good (well, one of the two available is good) but only shows EXPOSURE, not actual illness. My QH had a EPM scare last year and it was horrible. If you have any doubt, and can afford it, just go ahead and do the treatment. Its about $750 for a big horse.