Interesting (not sure if it's true or not): "To rule out rain rot, get a black light (you can find them in some of the discount catalogs for under $20) and take into the barn at night and turn it on. It could be many things from scratching from no-seeums to rain rot to sunburn. If areas of the non hair parts fluoresce, then it's probably rain rot or a fungus."
Judy http://icehorses.net http://clickryder.com
