Skinny chicken question

[wehrlegirlskid]

I'm really quite lost as to what to do... I've currently got a chicken who has been recovering well after quite literally loosing the skin off her back when our puppy decided to "have fun" with her. All wounds have been closed up since a long time ago, she's religiously sprayed with anti-itch stuff so that as her lovely skin grows back, she'll be less inclined to create new wounds (and so far, no new wounds have popped up). She's got food, and water galore in separate no-spill containers, has lots of straw and is happily cooped up in a pretty spacious dog-crate at nights with another chicken who was in a similar (though less severe) predicament... though I've made sure these two are kept in separate crates. In the day she usually gets to wander around our horse barn as she pleases, unless the horses are staying in for weather-related reasons.

However, I've been noticing for the last several days that this chicken has been rapidly dropping weight, where the chicken she's been cooped up with is in perfect weight. Her comb is nice and red, she seems to be eating/drinking okay, she's not very old and I can't think of where she would get any parasites. I've been keeping her in to watch her and make sure she's eating, with a fan propped up next to her crate. I would love to keep her, as she's one of my favorites, but I'm not too sure what's going on...

Another thing is that she hasn't been laying eggs recently, and isn't currently on any worming meds...