Mane falling out

[CanteringCarrot]

I have a horse that has a long mane, and within the last month or so his hair has begun to fall out. It comes out very easily when I run my fingers through it. If I actually brush it, a lot more comes out in the brush than it used to. It also just feels thinner. His tail may be a bit thinner too, but hard to tell. Nothing has changed with his diet or environment. His work level decreased for a bit, but that’s about it.

His coat and skin looks good. The vet ran some blood tests and whatnot for mineral levels, but all were within normal range and appropriate ratios. Otherwise he is healthy. I think I may actually have to cut his mane because it is looking kind of stringy at the ends. I was considering it anyway, but since he is a “hair breed” as I call them, I was really trying to preserve that long mane, and did so with no issue for about 2 years. There are no signs of rubbing either. I have tried braiding and leaving it down, same result either way. It comes out straight from the root so no breakage or something like that.

What could cause this?

[beowulf]

No sign of rubbing? What’s his deworming schedule? Do you have a hayhut or some other round bale feeder? Those can make horse manes thin.

My gelding’s previously thick tail was thinning out drastically, and he just tested positive for lyme last month. We test every fall and he has never had it before.

[CanteringCarrot]

@beowulf

No sign of rubbing? What’s his deworming schedule? Do you have a hayhut or some other round bale feeder? Those can make horse manes thin.

My gelding’s previously thick tail was thinning out drastically, and he just tested positive for lyme last month. We test every fall and he has never had it before.

I just double dosed Ivermectin about 2 weeks ago. Prior to that he was dewormed a few months ago (beginning of May), but I cannot recall with what, I’d have to look. He has no hayhut or anything this year. He rubbed in his last year a bit. This year he is grazing on grass and eating loose hay or hay from his slow feeder net in his stall. There’s really nothing in his pasture, paddock, or stall. His stall leads to his paddock but no signs of rubbing on the doorframe or something.

Lyme is extremely rare to virtually non existent here. So there is a very small chance, but I don’t know that I could get my vet(s) to test for it based off of one symptom of losing mane.

It has been a very hot summer at times, especially for here, so it could be heat related? The hair on his face is quite thin or balding in spots, but he always gets that when he wears any fly mask 24/7. So not sure that is related.

[Baboo]

Is it possible he spiked a fever at some point several weeks back? I have a mare that lost her mane and about 90 percent of her tail post-fever.

[candyappy]

If you look along his neck under the mane is there any signs of bites or crustiness from bugs or gnats biting him there?