My young (17 weeks) recently acquired RI hybrid hen went more or less overnight from being lively and happy to being hunched up and sad looking, frequently standing on one leg and then the other. This has been going on for 3 days. She is still feeding well but small comb is very pale. I am new to hen keeping so a bit worried. Vet fees will be a problem so am hoping for some suggestions. Thanks, Roofey