I have a flock of 6 laying hens. 2 of them are showing signs of a respiratory condition. One is mouthbreathing and making little cheeping sounds. She has been like this for a couple of weeks. Thought at first it might be the heat. She is active and eats well, poop is ok, no nasal discharge but some head shaking occasionally. Last night another chicken was making loud breathing noises. So I'm sure they have a respiratory illness. After reading a lot of posts here on the forum, it seems that Tylan is one of the preferred treatments. My local Ag supply does not carry it, but I can order it on line. It comes as an injectable and as a soluble powder. Is the powder as effective as the injections? The injectable does not mention use in chickens, but the powder says not to use in laying chickens. In posts discussing the use of Terramycin, it was suggested that you not eat the eggs for 7 days after treatment. Is it the same with the Tylan? I would appreciate any advice. I have purchased Tetracycline and am using it in the water until I can find something better, unless this clears it up.