It seems to me that the rate of sweetitch has gone through the roof and that it fits exactly with the number of fat horses around now.
I took on a horse with very severe sweet itch three years ago. I sorted out his diet, got him a lot thinner and fitter and guess what - the sweet itch disappeared. This was a horse who had had to be rugged head to foot even in the stable.
If anyone has a horse with sweet itch that's also fat (be honest!!!!!) try getting the weight off and maybe you can stop spending money on wrapping your poor itchy horse up in rugs all summer.
Please don't jump down my throat anyone who has a thin horse with sweet itch. Yes, pure midge bite allergy does exist. But so does midge bite allergy that is only present when the horse also has an overworked liver.