They are eating & behaving pretty normally, a little less active though. No discharges, normal poop. They are 6 years old. Yesterday I brought them in to the house to keep warm, & am giving erythromycin + vitamins & electrolytes for birds dissolved in their water. I can't tell for sure, one might sound a little better today. I am trying to figure out what's wrong but it's hard with only one real symptom. I gave up taking chickens to the vet a long time ago. They would order expensive lab tests & then say they didn't know what the results meant because they didn't study chickens in school. Thanks for any help.