Horse sensitive to bug bites

I have a new horse that is getting large welts/hives from biting flies that just started a few days ago. I had her in full fly gear but she’s just pacing and sweating when turned out to graze.

Anyone had any luck feeding garlic or any supplements that will keep off biting flies? The only spray that works is human OFF (I’ve always used on trail rides and never had an issue). My other horses are doing fine in the fly sheets and even one without and they have no welts on them so I know it’s some kind of allergic reaction.

Ive never had a horse with such a sensitivity to bug bites! Any advice from this that have dealt with this is appreciated! Thanks!

I’ve noticed that every time I have a new horse—one now—here in south central TX that they react to bug bites. They seem to eventually move past it (short of hornet stings) so not sure if they build up an immunity to local bugs? Somehow they learn not to lie down in a fire ant pile? I also have full fly gear but when it’s upper 90s-low 100s, it’s just too dang hot. I’m wiping on 13% permethrin now with fly masks for their eyes. But I’ve also never seen such a bad year for bugs as this year. Bar none in 21 years here. THey’re invading my house too and tonight I was literally attacked by giant mosquitos and they generally don’t bother me. WTH??

My husband’s gelding has horrible reactions to gnats and other bug bites. A regular fly sheet wasn’t enough but the Rambo Hoody made a huge difference for him.

I put him in his fly sheet weeks before anyone else and he’s also the first to get fly boots and mask on. We also use the Rambo riding fly sheets when the bugs are bad on the trails.