OK. So this morning my husband goes outside to let the birds out and finds our Red Ranger pullet (born 7/7/14) named Beep laying in the middle of the coop on her stomach with her head to the litter. She was still alive then, looked up at him when he came in, but he could tell by her heavily labored breathing that she was about to expire. Sure enough a couple of minutes later she went into her death throws and collapsed fairly quickly. He also found just a little bit of blood along the wall and when he lifted her body, a bit more came out. I haven't seen any blood myself. Rest in Peace, Beep. She was a lovely little chicken. Funny and sweet and a really good layer. I'm glad she's not suffering anymore. Anyway, now I'm trying to figure out what happened. This is what I know: She was just fine yesterday. Eagerly running up to me for treats, pecking about, eating, and acting normal. Didn't notice any odd behavior from her. Feathers in excellent condition, no parasites. No evidence of outside injury but comb and wattles were blue. So no oxygen. Opened her up and started from the top down. Beak had a bit of mucus around the mouth. She seems to have spit up a bit. Trachea were pink and healthy, no signs of parasites. Crop partially full with food, same with the gizzard. Muscles blue. Black fluid in body cavity. Clearly she's not had proper oxygen to her organs and muscles and the inside smells unbelievably foul. That's as far as I could get. This is my first chicken necropsy and the rest is just too black for me to study and figure out the origins of the problem. I don't see anything obvious beyond this foul blackness. Any ideas?