I have recently acquired two year-old hens that have been separated from the rest of the younger flock except for one quick instance of "escape and mingle." One of the new hens is now showing cold-like symptoms (sneezing, shaking head, snot bubbles on nostrils). I am treating the whole flock with antibiotics and VetRX, just in case. Do I get rid of the sick hen, get rid both of the new hens, or is the damage already done and I should integrate them once the course of antibiotics is through and everybody seems to be feeling better? I am willing to have the sick bird tested for MG if necessary.