When cooped up, chickens or any birds need shade. They can and do have heat strokes and die.
I got a Dominique rooster for free from a woman in Screven,GA because she did not want it no more because it kept (Humping) everything. I started to notice that he has been throwing up and has runny stool and panting like a dog. I give my chickens fresh water daily and feed them scraps from the table and cracked corn. I don't know how to worm a chicken if that's what I need to do. I now have a fan and shade in my chicken coop and they seem to enjoy it. Could it been to hot from him? (My first thought). I do not have any records on the rooster since I had him. What could be wrong with him? I heard it was because of sour crop... What do I do for sour crop?! HELP!!!!