I agree with quarantine - better safe than sorry. Also, I do not guarantee this will not have adverse affects, but I have put gobs of Vicks Vap-o-rub under the wings of chickens with breathing trouble and gotten good results. It started with some turkey poults I was given that were just a few days old: we tried everything - drugs, vitamins, cod liver oil, weird concoctions - and we were going to give up. I called my husband in tears, and he was going to put them out of their misery when he came home from work. In desperation, I slathered the Vicks under their tiny wings, and shut the door to their room, fully expecting them to be dead by morning. Rob woke me up when he came home: the little rascals were running around like they'd never been sick! This winter, I had a silkie with bubbly eye and sneezing, later PBR's coughing, another time wheezing BA's and mixed chicks - one treatment with Vick's and they could breathe clear. In some cases, I also gave a round of antibiotics just to be sure - Vicks is for a symptom, not a disease. I did switch to using Baby Vick's on chicks(figured it was less likely to be toxic), just in case.
If you get desperate, I would consider trying it, but again, although I have had no problems with it, I do not guarantee that it is completely chicken safe. Good luck!
