Where are you located? Has ther been any outbreaks of Newcastles disease or avian flu in your area? Have you wormed your chickens recently? If not I would give SafeGuard liquid goat wormer 1.25 ml orally for. 5 consecutive days. That treats gapeworms. Viruses can sometimes cause gasping. I would start a new thread of your own, so that others can offer help.My hen is doing the same exact thing.