I have had 3 birds on quarantine and have been practicing good biosecurity they have been outside across the property completely separate from all others. If has been over 30 days and I was just thinking maybe all was ok when today I saw that 2 out of three have yellow mucus running from their nostrils but no other symptoms at all not even sneezing . I have read all the treads and links I can find and will not treat with antibiotics but have a few questions still. Are all forms of these "colds" ones that carry forever in the chicken? and is is so wide spread that culling these would make no difference because wild birds can bring it in as well? Or is it my duty to cull them to try to keep a lid on it. Should I just keep them away from all other chickens their whole lives even when they are "better" My flock has never shown any signs of this and I don't want them to. Would it be irresponsible to sell hatching eggs from them? this is of course if they got better with no antibiotics just supplemental support. UPDATE: Ok so I went out to check today and both are fine, could it be that food had gotten built up there when it rained and some got wet and that caused a blockage, that when I wiped it off they had a runny nose for a bit? All I gave them was yogurt and now they are perfectly fine, no snot anywhere clean as can be.