Hello all, I have four little 3 wk old chicks and they have been on probiotics a couple of days as one of them, the smallest, has had a cough. Also one of them is kind of a runt and is very slow to grow, not many feathers yet. My question is the others are starting to pick at it's back and shoulders. Is there any advice as to what to put on him before the others possibly draw blood? I don't want to separate him unless nothing else is possible he would just be to lonely. Thank you so much!