My pony's tail is just growing back now.... I don't know if she had ~that~, but she does rub her tail out every summer, and just seems to itch too much all over. All gone now, but she is a scratchy pony in July.
Grace has all the classic symptoms. The skin in the affected areas is thickened and scaley, especially the root of her tail and mane. It looks like the Michelin man, all ribby and hard-feeling. Her belly looks wrinkley too and has crusty sores all over it, and her legs look all bumpy. I just hope she gets some relief this winter and it goes away for a little while. I didn't know what it was earlier this year in time to make sure she's sprayed with a repellant all the time. That website that I posted earlier has a 98% DEET spray that I may look into. They also recommend applying heavy oils on those areas that the midges like to feed on because they don't like to get stuck in them. But the best prevention is a sheet like this...
It's breathable, stretchable, acts as a sunscreen and there's a hood that can be worn with it to protect their face. Maybe that's what she needs. They sure are expensive, but that may be what it takes. Either that or she needs to go live with Duchess in Nevada where it's too dry for culicoides. ;o)