We recently got 2, day old guinea chicks that were kind of inactive( probably from birth). Anyways, we got them from a friends father who owns several free range guineas. when we got them, we decided to put a little heat lamp to keep them warm. The next day, I looked into their little pen, they both were laying sideways and silently opening their mouth and "crowing". I lifted one of them up and the body was completely limp. They had food and water in case if they needed it, but this has happened to one of our silver laced Wyandotte hen. My silver laced Wyandotte had boogers and eye crust and smelled pretty bad, but it kept moving with the herd. I noticed what is was doing, so I put it in a cage and gave it Titracyphene( I think I spelled it right) and hoped it got better. The next day, it was dead with a grayish film over its eyes. I don't know what could cause this, but I have never seen anything like this. The Birds both had clean food, water, bedding, and there were no unhealthy chickens.