Causes of hip/thigh twitching other than PSSM/HYPP

[BackintheSaddle2]

My Paint’s hip/thigh area started twitching about a month and a half ago, and I am still working with the vet to determine the cause. A few notes:

1. The twitching affects both sides and occurs at rest; exercise doesn’t play a role.
2. The muscle enzyme levels in the blood work are in the normal range, even after exercise.
3. She has been on vitamin E for about a month, just in case it was a deficiency issue, but there hasn’t been any difference.
4. Lyme is rare in the area, so it’s unlikely Lyme disease.
5. Chiropractor said her hips were out of alignment and said that could cause twitching, but the twitching didn’t stop after the adjustment.
6. She isn’t showing any weakness in her back legs.
7. She doesn’t have Impressive bloodlines.

I do intend to do the genetic testing to confirm it’s not PSSM, but I wanted to see if anyone has had a similar experience and if it turned out to be something other than a muscle disorder.

[JB]

I have NO idea if twitching can be a symptom of this, but maybe worth testing for anyway
https://www.vgl.ucdavis.edu/services/horse/IMM.php

What’s the whole diet? Have you tested selenium, or tried supplementing electrolytes for a bit?

[Postandrails]

Some extra magnesium would be another one to try, and if a deficiency was the cause then results would be quick.

[BackintheSaddle2]

Thanks, JB!

When she started twitching, her diet consisted of eight flakes of grass hay a day, so any deficiency would have made sense.

Since the twitching started, I have transitioned her to:

1. 6 flakes grass, 2 flakes alfalfa
2. 1 scoop platinum performance
3. 2 cups of Purina Outlast (she started acting girthy–this seems to have helped)
4. 2 cups of Triple Crown 30% ration balancer
5. 4000 IU of Elevate (vitamin E)–total Vitamin E is about 5000 IU with the TC and platinum performance

In addition to testing for muscle enzyme levels, we did check for sodium, calcium, potassium, phosphorous, etc. that all came back in the normal range. I had asked the vet about selenium, and he said that we live in a very high selenium area (and the hay does comes from this general area), so likely not a selenium deficiency.

I could try supplementing for electrolytes in general if that isn’t properly covered in what I have added to her diet above.

Edit: Thanks, Postandrails! I could try adding magnesium. If a deficiency would resolve the twitching, it wouldn’t hurt to try for a few weeks and see how it goes.

The vet says that her case is interesting because most horses that have twitching flanks have very significant other health issues, and my horse seems to be otherwise healthy. It’s why I am reaching out to see if anyone had a similar experience and came to a diagnosis/treatment.

[Postandrails]

If it’s due to a magnesium deficiency you would probably know within a week.

As someone who has previously had a severe magnesium deficiency myself, I can confirm that I had lots of involuntary twitching going on (among other things). Once I started taking magnesium everything changed within a couple of days.

It’s definitely worth trying.

[Mouse_amp_Bay]

Any issues picking up a back hoof or backing up? Typically not found in mares but I’d be putting shivers on the differential list as well.

Hopefully your diet tweets will improve things. I personally would spend the money to get a vitamin e and selenium baseline before you supplement. Not because it would be harmful (well, maybe the selenium but your vet doesn’t seem concerned) but because I would want a comparison after a few months of supplementation.

[JB]

@BackintheSaddle2

Thanks, JB!

When she started twitching, her diet consisted of eight flakes of grass hay a day, so any deficiency would have made sense.

Since the twitching started, I have transitioned her to:

1. 6 flakes grass, 2 flakes alfalfa
2. 1 scoop platinum performance
3. 2 cups of Purina Outlast (she started acting girthy–this seems to have helped)
4. 2 cups of Triple Crown 30% ration balancer
5. 4000 IU of Elevate (vitamin E)–total Vitamin E is about 5000 IU with the TC and platinum performance

Given that a lot of hay is high in iron, and therefore low(er) in copper and/or zinc, given that PP provides a very unbalanced ratio of those 3 (lots of iron, way too little cu and zn in relation), and that you’re under-feeding the TC 30 (which is more like 3c/lb, with a minimum 1lb feeding for adult horses), a suggestion would be to drop the PP and increase the TC30 to at least 1lb. Even then, copper and zinc may still be too low, but without a forage analysis there’s no way to know by how much.

I could try supplementing for electrolytes in general if that isn’t properly covered in what I have added to her diet above.

Edit: Thanks, Postandrails! I could try adding magnesium. If a deficiency would resolve the twitching, it wouldn’t hurt to try for a few weeks and see how it goes.

Electrolytes may work faster than Mg, as depending on the form of Mg, and how much you feed, it could take several weeks to a month or so before levels rise enough to make whatever difference they’re going to make. So IMHO, I’d start with a good e-lyte paste or powder, doesn’t matter, and see what happens. If nothing, then move to Mg.

[BackintheSaddle2]

Mouse&Bay: Thank you! She doesn’t have a problem lifting her back feet, and I don’t recall any issues when I back her up. I will keep a close eye today to make sure and into the future as well, but I think she is ok. I agree on the Vitamin E/Selenium baseline, though I suppose it would only be a baseline between how she is now and what she will be in the future. I missed the opportunity to do a true baseline blood test before I started supplementing.

JB: Great advice! I have been transitioning her to the ration balancer and will add the last cup to her diet next week. Her diet has definitely changed over the last month (for the better!), and I am trying to do it slowly. I will start with a good electrolyte powder as well.

At the very least, her nutrition will be closer to where it needs to be after all of this, and hopefully the twitching will resolve as well.

All this is very helpful advice to discuss with the vet. I may also have the chiropractor out again to make sure there isn’t any obvious unresolved back/hip pain after her last adjustment.

[BackintheSaddle2]

So–a quick follow-up to this conversation. I have been under the assumption that I should be looking for other alternatives to PSSM because her muscle enzyme levels are in the normal ranges and her twitching in the flanks is constant.

Is it correct to assume that those two pieces of data make it unlikely that she has PSSM?

[Bluey]

Over 50 years ago, so before we knew that much or how to test for it, we had one of our school horses, that we also used in endurance rides, have some odd time twitching of his back end.

We immediately started watching him for what at that time was called tying up.
That went on and off for some months.
He never had any soreness or not wanting to move, no lameness, no dark urine.
We had him on a very strict management for tying up, in case that is what it was.

Then, one time, after a long trail ride, he did clearly tied up, still lightly, but clearly that was his problem.

My point with this story, seems that for some horses, they don’t quite tie up but minimally, at least when it starts affecting them.
That means, some may have some of those metabolic disorders not quite show up as more than occasional twitching.

My advice, he may be compensating enough not to have any more than those twitches, but with what we know and can measure today, keep looking, it would be easier to manage if you know what is going on.

[Fillabeana]

So, while your mare doesn’t have Impressive bloodlines on her papers, since she is a stock breed you might do well to test for HYPP anyway.

While it’s not likely, it is possible that an ancestor was recorded in registration papers that wasn’t accurate. Before so much shipped semen, AI breeding, and DNA testing became common, unintentional mistakes wouldn’t be identified.

So theoretically, a breeder could have had two stallions in two different pastures…a mare could have gotten out of her pasture, and put back in with the other stallion…and the paperwork might have the wrong stallion on it.

It’s a long shot. But you’re already going to test for PSSM. And she’s showing symptoms that look like they might be HYPP. My two cents…you shouldn’t firmly rule HYPP out because there’s no Impressive ancestry on the papers without a genetic test.

[BackintheSaddle2]

Thank you, Bluey and Fillabeana!

Bluey, I agree–something is not right, and I should figure it out now while it’s still in its early stages.

Fillabeana–Yes, I think I will just do the whole 5-panel test, which will rule out a few disorders that have been mentioned here: HYPP, IMM, (which JB mentioned above) and PSSM 1.

[bugsynskeeter]

IMM is not a part of the 5 Panel. 5 Panel technically means: HYPP, GBED, HERDA, PSSM, and MH. What is now being referred to as an AQHA 6-Panel includes IMM. APHA 6-Panel includes LWO, not IMM.

What is her pedigree?