Bard rock Hen. Have had her 2 months not sure of her age. No recent flock additions. No Previous signs of Illness. I observe chickens daily. This is first symptom I have seen. coop cleaned yesterday as it is weekly, new hay placed down. This morning slow to get off the roost, picking but seems listless. Has a cough. has a wheeze when you listen to her breathing. No signs or symptoms in any of the others. Have a total flock of 12 hens and a Rooster. Big-ish coop, 40' x 40' open air yard.. so over crowding is not an issue. Well fed.. I make them oat meal for breakfast every morning. Really hate to have to cull her out.. has a name and everything. Anyone have a suggestion? Update.. Have put her in isolation.. appears to have hemoptasis (coughing blood) Barred Rock (Priss) is still hanging in there eating a little and not coughing as much, now a second hen, a Golden Comet ( Eggs) is having raspy breathing but no coughing. Treating the whole flock with tetracycline. If a second one is showing s/s of a resp. infection, thinking the whole coop has been exposed. The sick one and one who might be getting, sick came from the same farm. They were purchased as adults as this is our first foray into the chicken farming thing. They were supposed to be test/learning chickens but have quickly become loved pets.. with little wonderous orb benefits. No signs of any problems over the previous 2 months that we have had them. No exposure to any other poultry either. Is it just coincidence that the respiratory ailment started with our first really cold nights? Coop is not drafty but has ventilation. Could this be something that they carry? Is it common for resp. problems with the change of the season? Am trying to research. All I am finding is talking about vaccinations. I am looking more for treatments.