i went into the coop to check on my hens and found one of my buff orphington girls dead. She looks like she exploded. her head was laying in a pool of black foamy stuff coming from her nostrils and beak. There was blood on her abdomen and her vent looks like it had blown out and was covered in a diarrhea looking mess. she smelled horrible. She was cold and limp. I'm heartbroken as she was one of my original girls when I started keeping hens about four years ago. The rest of the girls seem okay but I am not sure what I should be watching for to keep this from happening again.