I have a FBC Maran pullet that is approximately 4 - 5 months old that had a respiratory infection--she was making a "wet" rattling sound when breathing, had somewhat labored breathing (she would stretch her neck out a little when trying to inhale), and had a sharp cough that was so forceful it actually made her stumble a few times; I also noticed she had a decreased appetite and general listlessness. I brought her inside and gave her Tylan 50 injectable (.5ml injected into breast) twice a day for 3 days and she seemed cured/completely recovered by the end of the treatment. Several more of my birds also seemed to have runny noses and some sneezing during the same time I was treating my FBCM. However, their symptoms were milder and they all were eating, drinking, and behaving normally, so the rest of the flock was treated with Tylan soluble powder in the water for 5 days. It has been 6 days since she finished the injections, and the rattled breathing and cough are back and as bad as ever. Was the Tylan dosage or frequency wrong? Is there anything else I can do? I have a tiny "flock" of 12 and this pullet has been my favorite since Day One.