Hi! I have a 6 year old barred rock hen. Just this morning, I noticed she is sneezing every now and again and sounds like she has mucous in her throat (not just the normal sneezing from dust). Other than this, she seems to be okay. Eating, drinking, red comb/wattles, no discharge from eyes/nose. She even laid an egg today. She's already not very active, she has had a limp for the past few years which slows her down. We introduced 6 pullets to our flock last week after they were in quarantine for awhile. They all appear to be healthy. Does anyone have any ideas?