I have had birds of all sorts since I was little and NEVER heard one cough. I've heard plenty of sneezing but my new Cochin Goldlaced Banty Rooster makes a noise like a cough. He seems fine, healthy. Eating, mating, clucking, crowing flapping, strutting. His crow is nice and loud and robust (for a banty) but he also makes this noise that sounds like someone with bronchitis coughing. He seems to do it mostly when I am putting them up for the night. Their coop is not finished so every night I pick them all up and put them in a secure hutch. The hens go in a little travel box but I carry the rooster and he will often cough. I don't know if anyone has ever heard anything like this.