I have 9 chickens ranging from .4 to 1.5 years old. The 2 BA are having a problem with feathers. Around their necks and a small way down their chest is naked. I see no sighs of lice or mites. I did a great job cleaning the coop 5 weeks ago and with the new wood chips put 1/2 5 gallon bucked of DE mixed well. The inflammation went away but it is to early for the feathers to return. All the birds sleep together in close quarters but none of them have this problem. I keep reading the Chicken Health hand book but nothing even close. What could this be? Laying everyday, active, eating well, bright eyes. I supply fresh water and feed every day. I clean regularly so I just can't figure it out. With the dry weather we have lots of flies everywhere but this all came along months before. What should I do. Could this be in the breed? I would hate to have to put them down but I am beginning to wander if that is what I should do. Please help me fix the issue. John