I have a 2 1/2 year old production/polish cross chicken that is sounding strange when she breathes. When she breathes out, and sometimes in, she makes a "brrr" noise, similar to a trolling chicken, but it doesn't seem normal. When she makes this noise and sometimes when she isn't she breathes hard enough you can hear her. Occasionally she sneezes, but there doesn't appear to be discharge from her nose. What do I do? What do you think she has, if anything?I have two injured chicks indoors and a flock of chickens down at the barn so I can't think of another place to put her.