I just went out to my coop and my 9 month old blr wy. was dead. This is the 3rd "healthy" chicken I have had die in the last 2 months that I have no idea why. I spend more time with my chickens than most people think is normal! Everyday I hold, pet, inspect for nose, eye, strange poop, I really love and keep an eye on these guys. They are more pets to me than anything. I have now had a blue cochin, black langshan, my wy. and a couple of oeb die for no apparent reason. What could I be missing? I just cleaned the coop on Monday, plenty of vents, no ammonia smell at all. Any ideas??