I have a red sex link hen hatched earlier this year, about March April ish. She is having a hard time breathing. Her comb is dark and her tail feathers are down. No other symptoms. I looked in her mouth looks normal. She eats, I haven’t seen her drink. I can’t feel any mass around her crop area or anywhere on her neck. I also felt to see if she was egg bound and didn’t feel anything there. She still runs from me and got away after my video I took. No runny nose eyes look good. I’m not sure exactly what is going on.