i have a year old cornish game hen that i keep around for eggs, who recently had the same thing, in conjunction with "coughing/wheezing" and regurgitating her water about once every 3 times or so, i want that worried bout it until one of my DOM's started showing the same coughing symptoms. i just got done hitting my whole grown flock with tylan 50 1/2 cc for LF 1/4 cc for the hens, i didnt inject i gave it orally down the throat with a syringe. anyways, along with no longer coughing/wheezing, her poopy butt has cleared up amazingly. dont know if you want to go that route, but just a experience.