I'll keep an eye on her inside. Do you have any idea what this could be? I'd think it was pulling out feathers except that when I feel the normal chickens they feel boney. Maybe I'll soak her in a warm bath this morning. I appreciate everyone's guidance.
I've been at work and just got home. It's warm, but not red. It is soft to the touch. I did check her for impacted eggs and it was empty. Later she laid an egg! There was an unusually huge poop in her cage. A friend looked at her and said she thought she had just plucked out her feathers...
Also when I just took her out of the box to transfer to an isolation cage there was a normal poop in the box so I don't think it could be anything like constipation.
This picture is of her rear end. Tail is at the top of the photo. The dark patch looks almost like a small dark purple bruise. She has a couple of these in this bare area and it seems swollen. Otherwise seems alert and fine.
I really don't know. She's one of 22. I let them out when I got home from work and she was grazing normally. I just noticed bare skin. Will get picture and send it in a minute. Thanks so much for answering.
I noticed that one of my chickens didn't have the fluffy feathers under her tail and when I picked her up, her abdomen was totally featherless and looked swollen. I felt around in case this meant that she had an egg stuck inside, but didn't feel anything. She perky otherwise. Is something bad...