I have a hen two hens that are breathing heavily and you can hear them almost gurgling when breathing. There is no discharge of nose or eye and no swelling. They act normal and eat normal, but i know something is not right. I understand the breathing heavy and panting because of the consecutive days of 100+ temps.. But the sound they are making when they breath is what worries me. One was doing it first then another. I have them and the entire flock on Duramycin-10 currently and one is somewhat pale in the face but her breathing is better and seems to be slowly recovering. However the other shows no improvement so far. Any idea of which respiratory disease I am dealing with here???