This morning I checked on the chickens and my one-year-old gamefowl mix, Myrtle ran out to greet me as always. She then proceeded to eat and drink. She seemed to have no symptoms at the time whatsoever. I then left the house for two hours, leaving the chickens cooped up, and when I returned, she was dead on the coop floor. She had no bites/cuts/missing feathers etc., the only symptom was that her facial skin was very dark purple, so that might indicate a heart/respiratory problem. No predators could have got into the coop and there was no sign of predators anyways. I will include a photo of her down below but be warned-it’s graphic. Anything helps, thank y’all!