They used to lay every day - out of 5 hens, we'd get 4 eggs a day usually. Then, about 6 weeks ago, they got red mite. We treated it, scrubbed everything & got rid of the mites but the hens stopped laying & haven't started again. They're all about 2 years old (3 hybrids & 2 ex-battery). They all look in a bit of a sorry state & have lost weigh. One of them seems to be losing all the feathers on her head. What could that be?
I've tried giving them extra greenery, grit, cider vinegar, treats, like corn and cake & have wormed them. Will they recover?