Hi. Found a 3 month old chicken(one of a group of 14--all 3 month olds) very lethargic this morning when I went to change water and refill feed. Brought her inside to warm her up and keep her out of the footpath of the rest of the youngsters. She didn't seem to have and injuries or blockage but 2 hours later vomited yellow non stinky stuff and died. Any thoughts? should I be concerned about the rest of the flock?