He's been sick for a few days now. He hangs his head toward the ground, his tail is nearly dragging on the ground and his feathers are always ruffled. Moves very slowly and hangs around the coop while his hens range all over. His comb seems darker than normal, I haven't noticed any diarrhea or discharge from his nostrils. He seems to have lost his appetite, but he will eat out of my hand (normally he would not let me that close). One potential cause is that my wife used weed killer in the area, but you would think that other chickens would be effected as well. I have a relatively new set up (last October), and the chickens free range over a four-acre area. Anyone have any ideas? This if the first time in 25 years that I have owned chickens, I use to raise them as a teenager and I've never had any diseases in my flocks.