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  Discussion on Horse "recovered" from EPM
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Member:
Mkuchta

Posted on Sunday, Nov 30, 2003 - 11:54 pm:

My horse was diagnosed with EPM 3 years ago. At the time it was uncommon and it took ~ 5 months before we got a correct diagnosis. He was treated and has recovered to a large enough degree to make him OK for riding. He is what my vet calls "sticky" behind. He seems to grow more sound and steady when he is ridden regularly 3-4 times a week. When this is not possible he occasionally "hops" behind at the trot. This looks like he is trying to canter for one stride then goes back to a trot.
Anyway, here's my question. This horse grows a thick shaggy winter coat everywhere except his right hindquarters (radiating out from his stifle). This hair grows shorter and looks different from the rest of his coat and from his other side. Can this be a sign of nerve damage? Can you think of any reason why this has happened? It looks sort of strange in the winter and he has had it the last few years. Can you think of any other reason for this hopping? Thanks.

Maureen Kuchta
Moderator:
DrO

Posted on Monday, Dec 1, 2003 - 6:24 am:

Is the initial episode of this hair coat pattern closely associated with the EPM episode? Without seeing the hop it is difficult to attribute a cause but you might check the article on Upward Fixation of the Patella: a common cause of intermittent "hopping".
DrO
Member:
Mkuchta

Posted on Monday, Dec 1, 2003 - 12:16 pm:

I do not know if the hair coat pattern is closely associated with the EPM episode. His hair looks normal in the summer but for the last 2 years there has been no growth in this area during the winter. I can't say for sure if this occured at the same time as the EPM, so it's probably unreasonable to ask you for an opinion about it :-).

Concerning the upward fixation of the patella, I never considered that this might be the problem. He has been examined by two area vets and neither mentioned this but I'll bring this up with my vet next time she is here. The hopping does improve when he is more fit and the hesitation only lasts for a fraction of a second. Is it possible that it only catches slightly?

Also, before a ride he tends to turn his right hind outwards and he doesn't track under himself as much on the right until he warms up. The more often he is ridden the less he toes out. Also he almost always stands in the stall with his right hind extended behind him. He almost never stands with both feet even with each other or the left foot behind him. He bends his left hind under and rests it but he never, ever rests his right hind. I took it as an indication that his right hind was stronger but now I wonder if he just isn't comfortable bringing it underneath himself. I took this horse to Cornell 4 years ago and they were unable to come up with anything. They missed the EPM (My vet caught it later.) and wrote it off as "Standardbred gaits". At the time they examined him he hopped occasionally at the trot and was also intermittently lame during the examination. To be fair, the lameness was hard to pin down, but no mention of neurological issues was ever brought up. Anyway, I have never been able to get a real explanation for the hopping which he has always done.

Moderator:
DrO

Posted on Monday, Dec 1, 2003 - 7:17 pm:

Right, since the hair problem is uncertain lets just call this cosmetic. What do the professional folks who have seen the hop call it? There are three possiblilities, whose differentiation is based on the appearance of the hop, that each have a different set of diagnostic rule outs:
  • Pain on weight bearing?
  • Incoordination or weakness?
  • Biomechanical interferance?
Once we know which it is we can list likely causes.
DrO
Member:
Mkuchta

Posted on Monday, Dec 1, 2003 - 9:57 pm:

Well, the vet at Cornell called it "Standardbred gaits" and did not have an answer. My vet who has seen this horse before, during and after the EPM seems to feel that the horse is "not in any discomfort".
He does not appear to be favoring his leg. He seems to be using this hopping to get himself going. If you push him to trot faster, he will hop less. He will hop sometimes when he is asked to go from a walk into a trot or when he is trotting and is asked to make a smaller circle or change directions. He does this more when anything slows him down. He has had this hopping thing since I have know him (6 years) .

During the EPM this horse tended to forge a lot, however he rarely does this now. I would say my vet does not think he is any pain but that it is incoordination or weakness. She has never brought up any biomechanical interferance.
Moderator:
DrO

Posted on Tuesday, Dec 2, 2003 - 6:09 am:

I don't know, in your first post the vet called the leg "sticky", this sort of suggests biomechanical interference, perhaps upward patellar fixation.

Chronic weakness and incoordination following a episode of EPM is almost for sure residual effects of the disease. If you are interested in other causes of hind limb weakness see the spinal cord and peripheral disease sections of the article » Equine Diseases » Nervous System » Diagnosing Diseases of the Nervous System.
DrO
Member:
4merri

Posted on Wednesday, Oct 20, 2004 - 9:48 am:

Hello:

I have recently acquired a 9 year old TB gelding. He is extremely passive. Upon Vet pre-purchase he was cleared, except for mild arthritic changes in his knees found by xray. History of the horse as it was given to me included western showmanship, hunt seat equitation and some hunter/jumper, then turned out for occational riding over a 3 year period. Previous owner claimed the horse was sound but out of shape. When I rode him to try him out he felt sound, a little rusty through transitions and off balance going, but I attributed this to not being ridden regularly for those few years, not being trained in dressage and my expectations were high and/or the footing was particularly deep.

I have had him about 3 weeks now. After working him only via lunging on a 30 ft.line for the first couple of weeks, I have noticed that he really seems akward especially as he gets a little momentum underneath him. When he gets a good working trot going he falls forward, then at the canter he bunny hops! and falls forward. At the same time he throws his whole rear end outward as is if he is doing a shoulder-in on a circle. I didn't feel this when I rode him. I have also noticed that he prefers to stand with both of his back legs slightly camped under him when at rest and his front legs crossed. He is easily able to uncross the front legs-I thought he was just limber and talented. I have never seen him romp and play in the pasture. He was on bute 1 gr. BID for his arthritis-"long term" but I took him off and kept him off of any meds for about two weeks just to see what his baseline "bad" days would be like. I saw no difference in his movement or behavior. Then by recommendation of an joint specialist at our University I put him on straight MSM.

In the mean time, about 2 1/2 weeks after obtaining him I got wind from a friend of a friend that this horse at one time, about 2 years ago was diagnosed with EPM. This was information the previous owner did not divulge. When confronted she admitted that he had, and was "with the best of medicines" for two months and was then cleared "WNL neurogically" by the vet. His diagnosis was made by a blood draw not the spinal fluid. I called the vet and he told me that the spinal fluid was no better at a diagnosis than the regular blood anibody test.

My question is this:Is it likely that the EPM has caused this resulting extreme passivity behavior, bunny hopping and falling forward at increased speeds? I am concerned as now that I know his true history some little behaviors that I shrugged off to not being in condition may actually be a long term affect of the EPM.

Comments? Help. thanks. Cynthia }
Member:
Ryle

Posted on Wednesday, Oct 20, 2004 - 10:45 am:

Cynthia,
I talk EPM every day with a group of owners who have been dealing with it, some for as long as 10 years. Some of their horses have recovered completely, but others do have residual neurological deficits from the damage done by the S. neurona. However, many of the horses treated for EPM also contract it again if they are put in situations of stress, especially long hauls and changing farms.
As for being diagnosed solely on the basis of a blood test, 50% of the horses in the US will test positive on a blood test (and as high as 90% in some areas of the country) for exposure to S. neurona, but far fewer will ever actually show neurological symptoms caused by the parasite reaching the central nervous system. A blood test is just a starting point for diagnosing EPM, but should be followed up with tests to ruleout the other diseases that can cause the same sort of neurological symptoms. A spinal tap gives you a much more accurate diagnosis as it tests for the presence of the protozoa in the central nervous system.
I would ask for a copy of his medical records from the previous owner's vet to begin with so that you will know what other testing was done when he had the neurological symptoms 2 years ago and what medication he was on. And talk to the previous owner and find out if he had been having any of these problems prior to your purchasing him and moving him. If he had not been having an issue prior to the move, then I would have the vet out and have him do a full neurological and lameness exam as this could be a recurrance of EPM or he could have some other issue.
If your vet is not very familiar with EPM (often the case), then you can suggest that he consult with one of the university researchers that study EPM.
If you are interested in getting in contact with other horse owners who have dealt with EPM, join the yahoo email list at https://groups.yahoo.com/group/EPM the people there are very supportive.

Good luck,
Cindy D.
Moderator:
DrO

Posted on Wednesday, Oct 20, 2004 - 10:57 am:

CynthiaS,
You are asking the wrong question. The question should be, "Is this horse suitable for your intended use?". The only people who know if the problems you are seeing at this time are due to the neurological disease are those who knew the horse well before and after the disease. It is possible but what does this mean? More to the point, if the horse is not suitable, the withheld information does give you a reason to question the sale.
DrO
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