My little pullet has been through a round of Tylan-50, and a round of Duramycin-10, and still seems to be gasping for air, and making gurlging sounds once in a while (I believe it's when she breaths through her nose). She still has black around her nostrils (I think it's dried snot). Otherwise, her eyes are bright, she's eating and drinking great. Seems to be in great spirits. Is there something more I can do for her? Or is this just the remnants of an upper respiratory infection?