I have a hen that is wheezing and breathing through her mouth. She has been picked on and her tail feathers have been pulled out. She has been pretty healthy but I pulled her out of the flock and put her in a crate outside the coop. I gave her olive oil and water but no changes. She does not leave the coop nor do any other chickens. She has clear eyes and clear nose no swelling of face. She coughed a few times that I know of. I have never had a sick chicken before.. she is still fysty.