I have 6 hens. One is 2 years old, the others are 1. One of them has been lethargic, not laying, has feather loss above her tail feathers, under her wings and on her chest, and is separating herself from the flock, so there is obviously a problem. Because egg production has been a bit lower over the past few weeks and a couple of other girls were missing feathers, I assumed lice or mites. I checked each girl (I saw nothing), then sprayed each with a garlic, lavender essential oil, and water mixture and sprinkled each with DE. I cleaned out the coop and sprinkled with DE, paying special attention to the cracks and roosts. She didn't seem to improve. Her crop is fine. She isn't prolapsed or egg bound. She is breathing fine. Her eyes are clear. She has had some diarrhea, so that I've had to bathe her and clean her vent feathers. She has lost quite a bit of weight. Her comb is a bit discolored and has some darkish areas. I can't tell if they are scabs from the rest of the girls running her off or pox. I'm open to suggestions!