One of my chicks hast started sneezing and acting weird. I had first noticed her acting different maybe like 3 days ago and yesterday I heard a sneeze but I wasn't sure who it came from until right now that I just saw her sneeze. She is a American game chick 8 1/2 weeks old. She is currently in with 2 other chickens (wellsummers her same age) should i separate them or should I might as well treat all of them? The wellsummers are acting just fine the only one who seems quite a bit "off" is the American game. What I have currently are tylan 50 and some medicine I brought from Mexico that's for respiratory diseases as well. Any help is appreciated. Thanks!!