Skin abrasions and plucked feathers

[aligoody]

I'm a new chicken mom to 3 - 24 week old hens. I've had them since they were about 8 weeks old. All has been well and they just started laying last week. Today I noticed my Australorp's feathers looked a little odd. When I checked, she has two sores on either side of her hind quarters under her wings (one side worse than the other) that have scabbed over. She is also missing a lot of feathers and her skin is red and irritated. I did observe that the other two were pecking at her and she kept trying to get away from them. I immediately isolated her and she is eating, drinking, and acting fine. We cleaned the area with peroxide and applied triple antibiotic ointment. No sign of mites or lice at all...everything looks clean around her vent. I have purchased Microcyn Poultry Care spray and "Pick No More" cover up lotion. Any ideas on what could have caused it? How long should I keep her isolated?

I took the photo just after applying peroxide. It does not appear to be infected at all. Thanks for any advice to calm my nerves!! I feel like a terrible chicken momma!

 

[aligoody]

wanted to update in case anyone finds this post in the future and has similar issues:

Lorelei has healed nicely! We kept her in a dog crate (in the house) for 5 days. She even lay two eggs for us! At least twice a day, we sprayed her wounds with MicrocynAH Poultry Care (from Tractor Supply). Today we applied Blu-Kote (also TS) to her sides because we plan to reintroduce her to the others. For now, she is in the crate beside the run so the other two can get used to the idea of having her back.

We carefully checked all 3 for mites and lice but they all looked clean. We sprinkled Garden and Poultry Dust with Permethrin in and around the run just in case there was anything bothering them...we did see a few fire ants. We still aren't sure about what caused Lorelei's wounds. We are hoping it wasn't just a case of bullying, but we will watch them closely and try to determine the bully and move her out for a few days to change the pecking order.