:| I have sveral New Hampshire Red hens and a Wyandotte as well as a Black hen. 2 red ones lost the feathers on their back and the skin is red. The Wyandotte is ok, the black is ragged and the other reds are a little ragged. I cant see mites or anything on them. I have used DE and dusted them, no results. I have 5 hens and get 3-4 eggs everyday. Their droppings look normal. I feed them laying mash and Oyster shell and they get table scraps and free range. I thought they were molting at first, but no feathers have grew back in the patches on their backs. I had been giving them vinegar in the water, but stopped several months back. Last year I had Plymoth Rocks that were fine....so what could be wrong with these? Help!!