I also have a little one that appears to have cocci. She is aprox. 5 wks old. Her mother and sister were killed by a predator in the chicken house when she was aprox 3 wks old, and she escaped. I put her in the dog carrier and she stayed in the house with me alone, until I went to the feed store about a wk later and got 6 more chicks to put with her. She did well until about 4 days later started looking fluffed up. Now she's still fluffed up and not active like the rest and although she was bigger than the rest when I got them, she is now the smallest. She is a Bantham and the others are 3-EE's and 3-Cinnamon Queen. They are probably bigger breeds I imagine, but she's just not right. I think she probably has cocci. I was wondering if it would hurt the others that don't have it, if I put the Corid in the water for all of them. I don't want to separate her from the others because they may not accept her when I try to reintroduce her after treatment, so I would like to just keep them all together and just put the stuff in the water for all of them. Also, can I dust them with poultry dust for mites that young. They are all about 5 wks old or so. I would really like to keep them all together since they all get along well now.