What causes baby foals to lose fur?

Currently I am helping take care of a 23 day old filly that my friend bought at an auction. She is about 3 weeks plus a few days and her hair loss is on her and on her muzzle. She did rub her raw and we treated that, skin grew back and all, but the fur loss spread from there. There was a auction sticker super glued above her tail (!!!>:() and before my friend had any say Bobby pulled it off with the fur... that however is the smallest hair loss on her. Not only has the fur not grown back where she rubbed it but seems to have spread to encase the space between tail and above hock. Right now the only thing were using is MTG or Mane-Tail-Groom that smells a lot like bacon bits.