We have a chick struggling. It breaths faster than normal, has droopy wings, and less desire to walk/run. One foot has crooked toes. Not sure if the toe thing is new or we missed it. It is about two weeks old. It eats, drinks, and poops normally. It isolates some, and goes with the flock some. It does not perch, and vocalizes very softly. We purchased six of its breed (Dominique), three died in the first week. Two deaths were unexpected in seemingly healthy birds, and the third had (lethargy/no eat/isolation/panting) for a few hours before death. A fourth developed impacted crop in the first week, but we were able to remedy it and its looking healthy again. The fifth is looking sick, which is the subject of this post. Of the six Dominiques, only one has really looked healthy the whole time. However, we purchased 9 other chicks of different breeds at the same time. They are raised in same environment and none of them have had any health problems and all look healthy. Three days ago, we started the water with antibiotics and "chicken gatorade", you know the vitamin electrolyte mixture. The amounts are carefully measured and are correct. This action followed the three deaths and the fourth chick having signs of sickness. Pictures can be sent if needed. What else can be done? what is wrong?