We have been fighting pasty butt with one of our chicks and don't seem to be having a lot of success. Yesterday morning she looked much fatter than the others and her feathers in back look kind of wet. Now she keeps going off in the corner and sleeping. Is there anything I can do for her? We have never had chicks before, and the other four seem fine. We think she and two others are four weeks old, and the other two are three weeks. Please help!