I have one with sweet itch and he would rub or bite himself raw and bloody, as you describe. He’s with me now for the 3rd summer and greatly improved. I think a number of factors contributed to the improvement. I’ve just tried things, one at a time, over time and each increment has been better than the last. Here are some things I have done over the last 3 years.
- Fly sheet with belly band, boots,and face mask when turned out.Put him on MSM to quiet the inflammation.
- Keep him inside during dawn and dust when gnats are most active.
- Added ground flax to his diet.
- Keep him super clean. He likes to sleep in his wet spot every night (ugh, I know). I ended up putting a breathable rain sheet on him in the stall overnight and that helped immensely. The flies are not nearly as drawn to him anymore. (Sweet itch is an allergy to gnats, but once that flares up he seems more susceptible to other fly bites as well.) Of everything I've doen, I think this has made the biggest difference.
- Treat the itchy spots/fly bites with aloe gel, vitamin E oil, or zinc oxide at first appearance. All of these have helped and also seem to act as a bit of a temporary barrier to flies irritating the already sore areas.
- During the summer fly season, he also gets spirulina. I usually start feeding that a month or tow before the start of fly season (so March/April).
- It has been part of my management long before I got him to keep my barn and pastures very clean, no excess standing water, use fly predators, and take what ever measures I need to to keep the fly population as low as possible. If this is not being done, I doubt the other measures will be of much help.
Benadryl, as recommended by my vet has been quite effective in breaking the itch cycle and slowing/stopping the rubbing. Ask your vet to recommend an appropriate dose. My horse has never shown any hives, just the oozing and crusting of the very itchy bites. Knock wood, so far this summer I have not had to use Benadryl at all. He is doing amazingly well compared to how he was when I first got him.
Also, have you had him checked for insulin resistance and low thyroid level? My other horse itched (and sweat) incessantly one summer. The vet wrote it off to unusually hot weather we had that year. When he continued to itch and sweat into the winter, I was sure something was amiss. I insisted we do some testing. Sure enough; he is IR and had low thyroid levels. Now that we’ve taken measures to manage that (Thyro-L and Heiro supplement), he is doing very well - only sweating or itching at times and in ways that I would consider “normal.”