Common mistake: NOT checking the chicken's nostrils in that they are clear and open.
Fix: Blocked Nare.
My favorite senior bantam hen had a blocked nare, nostril, from debris that built up and caused a hardened plug. The nostril appeared as a raised bump and I noticed her breathing through...
My small flock of bantams lives in a city garden coop. They are a delight to have here and I love them everyday. I, too, have put it off for years, then I decided that one cannot gain time back. So, until I get my acreage for farm animals, these chickens fulfill my agricultural aspirations...