I had a smouldering coop fire yesterday with mostly smoke. It was caused by a heat lamp. My chickens are between 3-4 weeks old. About half of them are still having breathing problems 30 hours later. They sound like someone having an asthma attack. They do appear to be eating and drinking normally. Do you think they have permanent lung damage? I'm hoping they'll get past this. These are our first chickens. Thank you!