Scratches only in the summer

My 19 y/o clyde/QH gelding has developed a persistant case of scratches each summer for the past 3 years, getting worse and starting earlier in the season each year. This year I’ve started to notice scabs climbing up his legs above the pastern.

He has 4 high white socks, and the scratches clear up like clockwork in the fall once we get frost again. Even through the muddy/wet fall and spring seasons his heels look great.

I’ve tried basically any and all medicated ointments, scrubbing with antiseptic washes, zinc ointments, topicals, etc. but this stuff won’t stop cropping up. It’s driving me nuts, and even though it’s pretty minor and never causes infection or soundness issues.

Has anyone ever heard of scratches only occurring in summer heat? I’m not sure if this is bug related or maybe some kind of UV or humidity sensitivity.

What’s the Summer diet, and what’s the Winter diet?

Grass, hay, feed (and how much), all of it

What kind of soil do you have?

IME MOST of the time this is a dietary issue, often resolving once sufficient copper and zinc are added. Sometimes it needs extra Vit A.

Often I see horses develop a variety of skin issues in early Spring, after a Winter of no supplemental Vit E and depleting their stores, but that usually goes away once they’ve been on grass long enough.

I have a thin skinned chestnut (no chrome) that gets scratches every summer. He has a great diet and I have tried several different things but have not seen diet make a difference for him. Our area is hot and humid and the grass gets very wet overnight, so I think that is the issue.

I have found that putting Shoo Fly Leggins on him keeps him from getting scratches. I don’t know whether it is the lack of bug bites or the fact that the Leggins keep the back of his foot dry but for whatever reason it works for him. Might be worth a try.

Diet in winter is mostly grass hay, maybe 5% alfalfa. Summer is muzzled grass for 12 hr and netted hay overnight in a dry lot. I have 3 of the easiest keepers ever, and it is a fight to keep them from being obese. They get purina vit/min supplement each evening as a bribe to get them in the dry lot. eta soil around here is clay but mostly dry in the summer.

The scratches seem to persist throughout the summer into late in the season. It seems the heat/humidity is the aggravating factor but I can’t figure out why it’s so late in his life he’s developing it. It must be some immune system factor but he’s never had any other chronic health issues that would be an indicator of something gone wrong.

Do the shoo fly leggings protect the heel? That seems to be the most vulnerable spot for the scratches on him and the pictures I’ve seen of those leggings it seems that they don’t drop down to protect the heel, just the back of the pasterns.

What is the purina vitamin/mineral supplement?? I’ll bet money the amount of copper and zinc in it is not sufficient.

Copper/zinc and flax has pretty much eliminated scratches/skin funk in all of mine.


On this horse the Leggins do drop down and cover the heel. That is the problem area for my horse as well.

How long is the grass? Is it still wet with dew when he’s out?
What plants are out there? Anything that could be contributing to photosensitivity/photodermatitis? Liver dysfunction can also contribute.

In another direction.
My 12yo gelding started developing rain rot and scratches every fall that required antibiotics. Last fall he also started have respiratory episodes. I took him for allergy testing this spring and it turns out he’s very allergic to a couple weeds that release their pollen in the fall, as well as a couple types of flies, and to top it off he’s very reactive to staph bacteria. It looks like it’s been creating this perfect storm and his immune system couldn’t sort it out.
He was already being supplemented with copper/zinc and Omega 3’s (DHA and EPA), which didn’t appear to help.

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Yup, same here, although I sure did have to play around with the amount for one of them–she needs FAR more than I would expect, and I also have to bump her up in July/Aug when she’s dumping summer coat and building winter coat.

No idea why she’s so different, but… horses :woman_shrugging:


It sounds like a photo sensitivity…you just need to find out what he is reacting to.

My friend had that happen with her gelding. Only white legs (3) were affected. For him, alfalfa was the culprit. His would start in July and August and it would take her until February or March to get them cleared up, only for them to start again in the sunny summer. She had done all manner of different goops, clipping, bandaging and antibiotics. Finally another vet saw him and gave her a mix of dexamethasone in DMSO gel and viola…”scratches” gone. He wanted her to remove the alfalfa from his diet. Once that was done, they did not recur.

I had a red headed mare that started to get this scurfy, scabby spot on one front leg and I tried her dex/DMSO stuff and it worked wonders. Also removed alfalfa from her diet.

The fly leggings would help by decreasing the sun on those sensitive areas (usually pink skin).


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The pasture is usually mowed to about 6", it’s definitely dewy when they go out but they go out in 1000x wetter conditions in the fall/winter and never had an issue. Pasture is mostly grass with patches of birdsfoot trefoil, it’s only about 3 acres so easy enough to spot weed patches and get them under control. I thought it may be buttercups so taken care of any of those I find.

Liver dysfunction, he has no other symptoms. No lethargy, loss of appetite, no photosensitivity on other white areas (large blaze, and white chin), no other skin sensitivities on the rest of the body. He’s generally a happy go lucky gelding type, consistent under saddle.

What did allergy testing entail for you GoodTimes?

I took him to a specialist for intradermal testing. We dropped him off at 8am, they sedated and injected the allergens, read it at 30 minutes and again at 4hrs. The vet called me for a quick consult and we picked him up around 1pm.
He just got his second allergy shot today. It can take a few months for them to kick in, I’m hoping he’ll have built up some tolerance by the fall.

They emailed me a very comprehensive report, along with some resources. They also suggested bathing him once a week with Prohex 4 (shampoo with 4% chlorohexadine) since he was so reactive to staph.


Shorter grass and thicker leg hair in Winter.