My family has a 6 year old Chantecler rooster who came down with an unidentified respiratory problem this winter. Though Chanteclers are generally tough, he is from a very inbred strain, which might be contributing to the problem. He was lethargic, sniffling and short of breath (i.e. his face would get purple when he exerted himself), his sinuses were swollen and his eyes were bubbly. His crow and his regular voice were sounding croaky. The two hens with him seemed to have mild sniffles, but nothing else. We first tried putting VetRx on his nostrils hoping that it would help, but to no avail. Then we tried putting high doses of Vitamin C in their water. This helped to relieve the shortness of breath and the lethargy; the hens' sniffles also abated. But still he was not fully recovered- I worried that he was being put off by the sour taste of the ascorbic acid (Vitamin C). So we stopped the C and began administering a mild antibiotic in the water, along with an electrolyte, for two weeks. The hens totally recovered, and he continued to improve, but still his crow sounds like a creaky door and his eyes are bubbly. The swelling has gone down but I'm not sure its completely gone. I have read that Tylan 50 works well, but I am not able to find a definitive dosage and\or a definitive injection site. Do you have any suggestions?