Our chicken's bum has been sagging for quite some time now. She stopped laying eggs. She had a build up of poop on her and my husband put on a glove and washed her off but it just came back. She also lost her feathers there and walks with a waddle because it sags so much. We have a mix of different kind of chickens and none of them have a problem, until today I noticed a young one that should have started to lay a month ago(same kind as other one) is starting to do the same thing. We have dusted for mites regularly all over and on chickens themselves. I have no idea what to do now. Please, any advice would be great! Oh, she is fluffy on the cheeks and fatter than our other chickens and lays green eggs...not sure what kind that is. Thank you!