Flock losing feathers at top of tail with red irritated skin- 2 exceptions Araucana & Rooster

[HagmanCoop]

We are new to caring for chickens and having a coop. We discovered that our hens were losing their feathers which started in a triangled area at the top near their tail. Some looked raw and I would see them sometimes pecking that area. Apart from that they are still happy and laying eggs as usual. We checked each one out and did not see any mites, we rubbed food grade organic diamethateous earth (DE) all over. We even applied tea tree oil to the area. We expanded their coop which we keep clean regularly. Several weeks later it still continues with the areas now growing bigger. One of the hens is no longer red and irritated but still missing the feathers in a larger area then before. Today we applied oregano oil to those areas and will reapply DE this afternoon. We are starting them solely on Feather Fixer feed with supplements and higher protein content and we are feeding them cat food once a day.

QUESTIONS:
1. Does anyone know what this is? Skin disease maybe?
2. How often can we apply DE to the hens?
3. Should we try oxytetracyline? If we do, how long do we add it to the water? Do we add 400mg or 800mg dose? How long do we wait after stopping the antibiotic before we can start eating the eggs again?
4. Why wasn't the Araucana and rooster affected?














Your help would be greatly appreciated!

 

[Eggcessive]

Welcome to BYC. That appears to be damage from the rooster overmating them, and is common with a young rooster, especially when there are not enough hens. Your Auracan may not be interested in him, or he in her. Hens will also peck these areas. Unfortunately, the feathers may not grow back in until the next full molt. I would put some hen saddles or aprons on them. I made some out of polarfleece that worked well. Here is a link with images of hen saddles: https://www.google.com/search?q=hen...v&sa=X&ei=w-I8VfD8EMmjgwSHnoDADA&ved=0CFQQsAQ

 

[HagmanCoop]

Thanks so much! That sounds very probable. There are 9 hens and he is the same age as the hens, 1 year old. He is always chasing the hens to mate with them. They try to avoid him but he gets them nonetheless. In addition, he hardly mates the Araucana because she has no interest in him and is the fastest of all the hens so is successful in staying away from him. I will checkout the link. Thanks again!