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  Discussion on Assymetrical muscle loss a sign of EPM?
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Member:
cmatexas

Posted on Monday, Oct 31, 2011 - 2:12 pm:

My daughter's 11 year old barrel horse is a very large, well muscled mare. She suddenly developed muscle loss around her withers on one side only. She has not appeared to have fever, lameness, or stumbling. Vet cannot come out for several days, but suggested over the phone EPM. Needless to say, this has struck terror in my daughter, who has the mare with her at college. I have not seen her in person. She is going to take pics of mare, and put her in round pen to get video of her movement, but says the mare seems otherwise fine. She did report that she was pretty "hot" the last few times she rode her, but it is a new barn and the turnout is different, and the arena is new, so she attributed it to "normal" things. I trust the vet, but waiting for several days will be unbearable for the 19 year old!!
Member:
vickiann

Posted on Tuesday, Nov 1, 2011 - 10:36 am:

Michelle,

Dr. O will have to weigh in here but it seems to me that many things could cause this to happen.

It seems a stretch to me that your Vet would suggest EPM based on so little evidence of that.

A horse of mine developed this kind of irregular muscling problem when a drill team that I was on kept working in one direction all of the time.

He became a very strongly left-handed horse.

In part I think that my horse became this way to protect his right rear leg that has always been slightly crooked and sustained a ligament injury many years ago.

Most horses will prefer one side as dominant to some degree but some horses are extreme about it. From what I have read, more are right-handed than left.

On which side does your daughter's horse have this muscle loss?

When your daughter is riding does she notice any tendency for her to end of twisting slightly to one side more than the other while underway and thereby putting more of her weight in one side of the saddle than the other? This is something that happens with a horse that is more one-sided.

Saddle fit issues can enter into the picture too.

A certified saddle fitter told me that a lot of mounting and dismounting always on one side may cause that side to become more muscled than the other as well, especially for those of us who do not use a mounting block. For this reason (and due to knee issues), I mount on the left and dismount on the right.

I have had some good results with using Len Brown's CorrecTOR pad on my left-handed horse. Mr. Brown helped me to figure out about my horse's left hand preference and explained how to use the shims accordingly.

It would be very interesting to compare the bottoms of all of your daughter's horse's feet as that can tell a lot about a horse's way of going.

Tell your daughter not to panic -- especially since her horse has not shown signs of being ill.
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 1:26 pm:

Muscle loss occurred over less than 4 days. Excellent farrier, fresh shoes, custom saddle, well balanced riding. This was a dramatic, noticeable change that happened very fast.
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 1:33 pm:

She sent me pics. Working on the post.
Member:
vickiann

Posted on Tuesday, Nov 1, 2011 - 2:17 pm:

That is certainly very frightening, and of concern that you can get no veterinary attention for "several days."

I would be afraid of some permanent damage due to a lack of treatment in some cases, such as with head injury.

Hope that you get some answers soon and that the problem can be dealt with.
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 3:41 pm:

Normal Left Shoulder
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 3:46 pm:

Right Shoulder Top View
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 3:49 pm:

Right Shoulder Side View
Member:
cmatexas

Posted on Tuesday, Nov 1, 2011 - 3:56 pm:

My daughter sent pics to vet. He said that the muscle loss appeared to be significant and shouldn't wait. She is hauling to another client's house in the morning for him to see mare. Yesterday in the round pen my daughter saw no evidence of lameness, and moved well at all 3 gates in both directions. Mare is not sore around area with muscle loss with normal palpation (by a teenager). McKenzie said it looks like someone scooped all the flesh out around one side of her withers. What in the world could cause this!!!
Member:
twhgirl

Posted on Tuesday, Nov 1, 2011 - 5:10 pm:

I don't have any answers but just wanted to say I am sorry you are going through this and I hope you find answers soon. I certainly hope it's not EPM. Please keep us posted.
Member:
vickiann

Posted on Wednesday, Nov 2, 2011 - 9:53 am:

Brown recluse spider bites can cause cratering, but in that instance one would expect to have some heat/infection/inflammation.

Have seen long-standing cratering of unknown origin on horses, which usually seems to be written off as an old injury due to a kick from another horse.

Let us know what you learn in this strange circumstance.

Wishing you a good outcome.
Member:
cmatexas

Posted on Wednesday, Nov 2, 2011 - 3:25 pm:

Vet said muscle had deteriorated on right side almost totally, and to some extent on left side. Most likely from trauma, but given no history of injury that we know of, then there is no way to really tell. Best guess was saddle pad.

Anyway, loaded her with steroids. Plan is to work her like we do the halter horses - interval training alternating long trotting and loping in both directions for 3 weeks, then some riding with LOTS of padding, again in both directions. Vet will see her again in 6 weeks if no other complications arise. By that time we should know if the muscles can be regained.

Anyone ever see this before? Any additional suggestions would be really appreciated. Dr. O - should I move post to another strand?
Moderator:
DrO

Posted on Wednesday, Nov 2, 2011 - 3:32 pm:

Hello Michele,
I think trauma is a far more likely cause to muscle atrophy over the shoulder than is EPM. But both work through the same mechanism: not damage directly to the tissue but damaging the lower motor nerve resulting in neurogenic atrophy. This may either be a mild, early, or unusual manifestation of a condition known as "Sweeny". For more on this condition see HorseAdvice.com » Diseases of Horses » Nervous System » Neurological Conditions Not Covered Above » Shoulder Sweeny. If you have questions after reading the article bring them back here and if this is indeed what you think is going on I will move the discussion to there.
DrO
Member:
cmatexas

Posted on Wednesday, Nov 2, 2011 - 3:37 pm:

No sign of neurological issues. No fever or other illness.
Member:
cmatexas

Posted on Wednesday, Nov 2, 2011 - 4:25 pm:

Dr. O - I looked at the other pictures. The muscle atrophy is not is the same location. It is the muscle attached to the withers. I texted the vet and asked if he thought it is shoulder sweeney. He said no, wrong nerve.

Questions:

1. If no trauma or injury was ever seen, could a saddle pad produce the type of trauma required? The saddle is a high quality saddle. The pad is older, but not noticeably degraded, and we always pull pads up off withers before cinching. If we caused this injury, I don't want to repeat it with other horses.

2. Is all muscle atrophy caused by nerve damage treated the same way? (i.e. stall rest) Or should we be working to rebuild the muscle as suggested?

I am not second guessing my vet - he is EXCELLENT. He's a lameness specialist from A&M (whoop) and the best we could hope for. I am just a science nerd (teach AP Chem and Physics), so I need to truly understand the mechanisms at play here. He is young, so I am hoping there is someone with experience out there that can give me a long-term prognosis.
Member:
vickiann

Posted on Wednesday, Nov 2, 2011 - 5:22 pm:

Michelle,

In my experience if a saddle does not fit a lot of extra padding makes things worse, not better.

You want the horse to round their back up under the saddle and use it properly rather than DrOpping away from the saddle.

You don't indicate that the mare palpates as having any back pain but one of mine had back pain along with muscle loss at one point in time.

I had the head of holistic medicine for the University of Florida Veterinary School come out and he did an acupuncture treatment and electrified the needles that he had placed in my horse's back.

In the case of my horse, he had to be given a few months off (as ordered by Vet) before we could go forward again, but his back was very sore.

My horse had saddle fit issues and had also taken a full fall under saddle when he tripped over a dog on the trail one day.

You might benefit from a conversation or E-mail exchange with Len Brown, inventor of the CorrecTOR pad.

He helped me out with some serious padding issues and I have met other horses/riders who he has helped as well.

I hope that you will have success in rehabilitating your daughter's mare.
Member:
cmatexas

Posted on Thursday, Nov 3, 2011 - 1:35 pm:

We know it is not a saddle "fit" issue. This is a custom saddle that has been well cared for and used without incident. Nor is she over padded. She rode a high quality pad with a wool show pad over it. The bottom pad was getting older (6 years) and was starting to look ratty. We wondered if it was in worse shape inside than we thought.

Anyway, after further discussion with vet, 3 things are being tossed around:

1. Because mare shows no sign of pain or discomfort during palpation, he does not think this injury happened recently. We leased this mare to another competitor about a year ago, and have speculated that it may have happened then. Looking back, there were other signs that may have indicated a wreck.

2. We are sending my daughter's saddle to be xrayed to check for breaks or stresses in the tree just in case. But, since we are not seeing any other sign of pain, this is a long shot.

3. We will never know what caused this!

Everything I've read says that nerves can regenerate, meaning the muscle can be rebuilt. But I do not know if best thing is to rest the mare or work her.
Member:
cmatexas

Posted on Thursday, Nov 3, 2011 - 1:40 pm:

Vet also said no chiro or acupuncture right now since we do not know cause of injury.

And thanks so much to everyone for kind words! This mare is my daughter's dream horse. McKenzie bought her with her own money and has taken her to college. She has money, time, effort, and love invested that simply can't be replaced!
Member:
vickiann

Posted on Thursday, Nov 3, 2011 - 3:35 pm:

The items that you have enumerated all seem to make some good sense.

Should tell you though, that I have a $3000 custom made saddle for my horse and when the certified saddle fitter who built it came back for a recheck about a year after making it, my horse's back had changed and it was no longer suitable for him.

Saddle fitter had me switch over to using a cheaper Big Horn saddle that I had in the barn for my horse.

Eventually that didn't fit either and after all kinds of trial and error finally found a good solution with the CorrecTOR pad.

Nerves can and do regenerate and I guess that I can prove that personally because I had nerve damage and parasthesia in my face (nerves were cut through)after a riding wreck, and most of them did come back to functioning. One side of my face had actually DrOpped but it repaired.

Hope that your daughter's mare will come around for her.

There's nothing like the special partnership that we can develop with horses that we love.

You can do a lot with rebuilding muscles through exercising and stretching.
Moderator:
DrO

Posted on Sunday, Nov 6, 2011 - 9:22 am:

We cross posted (my 3:32 did not see your 3:25 until after it was posted) above Michelle but before I replied further I wanted to do a bit of research on the anatomy and innervation of the shoulder. At first look I thought the infra and supraspinatus muscles may be atrophying. However this may be the trapezius or even underlying rhomboideus muscles, in which case he is right: a different set of nerves innervate these muscle groups.

Has the atrophy proceeded down the shoulder? Which muscles or tissues does your veterinarian believe is having trouble with atrophy? Do you still believe the problems is bilateral affecting both sides?
DrO
Member:
cmatexas

Posted on Sunday, Nov 6, 2011 - 1:21 pm:

Dr. O, the muscle atrophy is limited to the original muscle(s) closest to the withers. It does not appear to have spread "down" the shoulder, but it did seem to spread to the corresponding muscle on the other side, although not to the same extent. Dr. Lee did not mention which specific muscles were involved, but I will ask him. As of last night the atrophy was unchanged. She was lunged in both directions, still no sign of lameness.
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