Hello, I am new at keeping chickens. My chicken is sick. I am not sure what type she is (red with a little black on her tail). Her name is Marge. I have seven chickens and we let them free range all day and we lock them in the coop at night. They love being outside all day. Two weeks ago I noticed them all to have dirty butts, on closer inspection they were coved in lice (all seven of them). I cleaned out the coop and sprinkled sevin through the coop and one by one I placed each chicken in a pillow case and powdered them good. Eight days later I repeated this whole process. The other 6 chickens look and act fine. But the one is not so good. She has been isolating herself from the group and closing her eyes and resting most days, she even tucks her head under her wing. She is not eating as much as the others. Every once in a while she makes a weird respiratory noise. She shakes her head a few times a day (mostly after eating) she opens her mouth frequently. She does perk up if I bring out a treat. Yesterday, I looked down her throat and it was normal (I was looking for the gape worm that I had convinced myself she had). Today I put 30 cc Wazine-17 in one gallon of water for them (I don't think any of them have ever been wormed) she wont drink it. So I decided to really give her a once over this morning. She is missing feathers on her neck and near her vent. I did not see any lice or other bugs on her but she does still have egg clusters near her vent (they are now dark brown) The last time she went to the bathroom it was a small dropping of white with a little water. When I tried to look down her mouth today her beak was slimy and she had not had a drink because I was watching her. She is only 18 months old, and I don't know what to do. I feed them Gold Seal feed, grit, oyster shells, scraps, and they get to eat all the grass and bugs they want.