help me figure out what's wrong?

[Leah S]

I have a black australorp about 1 year. Noticed about a month ago- ish she was loosing some feathers on her back, by the base of her tail. Assumed it was a molt as some of her buddies are molting too. She has become less peppy, lagging at the back of the flock when they come to see me. She is eating, drinking and pooping fine. I looked her over for bugs, and found none, but a HUGE bald spot on her tummy. The feathers that I thought she was loosing are actually broken off and some stripped going all the way up her back. It seems like it could be mites, but cannot find one on her.
Would it be harmful to dust her, and her friends and the coop if it's not needed? If it's not mites, what could it be?
thanks!
Leah S

 

[BuffOrpington88]

I don't think it would harm them to dust them. Some chickens take longer than others.
Good luck!