I have a 4 month old EE pullet that us all fluffed up and weak. I first noticed her acting a little off on Sunday. I don't see anything specifically wrong, no sneezing, no discharge or swelling, I haven't noticed any unusual poop. I isolated her yesterday and have been treating her with VetRX but am not seeing any improvement. I did put some duramycin powder in her water this morning. The reason I am treating her with VetRX is one of my Cochin hens had a respiratory /wheezing /sneezing thing 2 weeks ago. She started showing improvement within a day from the VetRX and is fine now. I'm afraid a new pullet I brought into my flock 3 weeks ago is the cause. She is fine and has never shown any signs of illness, but I think she is a carrier of something. I just don't know what the most likely illness is and how I should treat it. Should I worm her while she's sick? I have never seen any signs of mites or lice in my flock. Any suggestions as to which disease she could have and the best way to treat it? I have some tylan injectable but it's expired and don't know if it would be any good. I'm also thinking I should treat the whole flock, too.