Large Horse Flies Biting Very Back Part of Sheath Between Legs

I always thought my pony had sweet itch as he is forever walking over baby trees to scratch his sheath. But upon closer inspection his sheath was fine, but way back behind the sheath (in his crotch, so to speak) were big horse flies (nasty ones with the green heads) biting his crotch bloody. Very hard to see whats going on. Basically need to stick my head way under his sheath with a flashlight. My friend gave me her alpha shield, but I’m a little intimidated to put it on. I’ve just been putting swat up in there every other day. But it doesn’t last more than 2 days in there. I think it just drips into his tail. Anyone else see this kind of thing?

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The horse flies here like to land right in the “entrance” of the sheath. Poor horses go crazy trying to dislodge them. In my area, the horse flies are most active in the early evening. I keep the horses in the barn during that time as much as possible as that seems to be the only real relief.

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I have just accepted that I will continue to be amazed by my fella’s unbelievable tolerance of Mom climbing around between his legs and coating his man-bits with Swat.


This was a timely discussion. I’ve been dealing with my horse’s allergies and just figured all the rear leg action was because of those. Took a closer look the other day when he was kicking out and sure enough there was a horse fly up there making trouble. Got me some Swat and hope that will help. They come flying into the grooming stall even. Jeeeeesh! If it’s not one thing, it’s another.

The really weird thing is that they don’t bother my gray horse at all. ???

I just use swat for my guy. I’ve also set up an h-trap to catch flies and that, combined with keeping the grass short, has really cut down on flies.

I use Vasaline, creamy in a tube, for that area. The white creamy type has added Vit E, seems to not get as runny, stays protective, about 2 days. I also rub it on chests, midline, armpits, thickly. Then just a slick wipe with my thumb inside ears for any scabs there,

Swat works too, just doesn’t seem to last any longer for protection than the Dollar Tree vasaline. Swat cost more, not always available locally. Doing 9 horses every other day, price matters!

Color of horses does seem to attract more or less flies! Some here always have more bites than others will. Ours are inside all day hours because biting bugs and flies are awful, keep the horses moving all the time.


Thinking about changing from swat to diaper cream or vaseline. Do these work as well as swat? I’m going through way too much.

Don’t the green heads and horse flies hunt by sight, so repellents don’t work?

I don’t have any suggestions but want to say, poor guy. That’s gotta HURT.

I spoke too soon. Went to ride yesterday and the gray has fly bites, but on his chest. Sheath is still fine. So he got some Swat too. Sigh!

Horse flies are attracted to movement and dark colors. So maybe that’s why he mostly escapes!

My guy was swishing his tail madly the other day while I was riding. I hopped off and there was one on his sheath…felt so sorry for him…but also grateful that he didn’t buck me off!

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I mix Swat 50-50 with neem oil for this. It seems to work a bit better than either one alone. My horse is victimized by these awful bugs and he is sooooooo itchyyyyyy.

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I have been using bag balm (green can) on my mare’s udder with good success. I also put it in her ears. I always have to let her get a good sniff before applying. Bonus that it is also good for my hands.

One day I realized it was probably the first time I had used bag balm on a bag (minus a few times I helped in milking parlor, but that wasn’t the green tin stuff). It was a revelation