My chick, possibly 5 wks old, barred rock/americauna mix. Went outside for 1st time for 15 minutes today. 8 hrs later she is twitching her head..stretching her neck while opening her mouth wide. Shortly before that she was laying down funny and seemed like she counldnt stand for long. She was bought at a pet store along with another..they have been caged together at both places. He is showing no signs like her. They are on the medicated food which she is eating as well as drinking so I am lost? Any advice will be great. This is my 1st pair of chickens..and I have 4 more in a different area of the house which have never been around her. They came from a local certified farmer not the pet store. Thanks.