KauaiChickenMama
Songster
Hmm, to me, it sounds like your efforts DID work as you said they seem happy, egg laying is where it should be, and the chickens with lots of missing feathers have gotten a lot better. All positive. That’s half the battle right there. You did everything you could to address the problem by first doing a thorough cleaning. Your efforts were awesome and most likely prevented this issue from getting any worse. The missing feathers will grow back in time and extra protein can help with that. 
Have you continued to use the poultry dust on the problem areas as well as the Poultry Protector since you started this thread in April? I’ve heard good things about both of them. I just picked up some poultry dust yesterday. How do you like the Poultry Protector? I’m on Kauai and just had two young hens go broody back to back so I’m dealing with an active case of mites right now, myself. I see that you are in Florida so for both of us, our warmer temperatures and humidity are favorable by mites. Cleaning and staying on top of the dusting and sprays as a preventative should solve the issue eventually...or at least bring it down significantly. But the thing that strikes me as odd here is that you haven’t actually SEEN any mites during this whole adventure, is that right?? In my case, I’ve definitely seen them. They are very tiny though, and light in color. Some are so tiny that I could not feel them crawling or even see them on my own arm without the help of reading glasses.
Do you see your girls scratching a lot or reaching back to those bald areas on their backs? And you said you’ve never seen any of them peck at one another’s back, right? Do you happen to have parallel roosting bars? If so, they could possibly be pulling feathers of the hen in front of them upon settling down for the night. They can get pretty nasty as they jockey for sleeping positions.

Have you continued to use the poultry dust on the problem areas as well as the Poultry Protector since you started this thread in April? I’ve heard good things about both of them. I just picked up some poultry dust yesterday. How do you like the Poultry Protector? I’m on Kauai and just had two young hens go broody back to back so I’m dealing with an active case of mites right now, myself. I see that you are in Florida so for both of us, our warmer temperatures and humidity are favorable by mites. Cleaning and staying on top of the dusting and sprays as a preventative should solve the issue eventually...or at least bring it down significantly. But the thing that strikes me as odd here is that you haven’t actually SEEN any mites during this whole adventure, is that right?? In my case, I’ve definitely seen them. They are very tiny though, and light in color. Some are so tiny that I could not feel them crawling or even see them on my own arm without the help of reading glasses.
Do you see your girls scratching a lot or reaching back to those bald areas on their backs? And you said you’ve never seen any of them peck at one another’s back, right? Do you happen to have parallel roosting bars? If so, they could possibly be pulling feathers of the hen in front of them upon settling down for the night. They can get pretty nasty as they jockey for sleeping positions.