One of my 10-day old Orpingtons is not doing well. She's really quiet, looks hunched & puffy. I think this started yesterday, at least she seemed less active to me when I had them outside in the afternoon. Weight gain has been good up until now, but she hasn't gained in the last 24 hours (we homeschool, kids are weighing daily - gotta make this a science project ;-). She has been our biggest and most outgoing chick so the difference is striking. Stools don't appear appreciably different than the others. No obvious nasal or ocular discharge. Possibly somewhat increased respiratory effort & rate, but hard for me to tell. We introduced 3 new chicks on Thursday evening (they are 3 days old, different breeds). All of the new chicks as well as the other 2 older ones look fine, getting along fine, extremely active, eating & drinking tons. They're in a re-purposed guinea pig cage under a heat lamp, eating medicated chick starter & treats (oatmeal this morning, also egg yolk, dried meal worms, whatever they scrounge from the yard at playtime), grit, on newspaper bedding changed daily. She is still eating and drinking, although when I tried to feed her this afternoon, I noticed her picking up and dropping the food, not swallowing.
I've read the forums about offering things like Poly-vi-sol (no iron), Save-a-Chick, various antibiotics. . . Anything sound appropriate for this girl or just watch and wait?