I recently lost 2 chickens this week to a bobcat within 2 days. I have kept the girls in the coop since the incident, leaving 4 hens. Today I come home from work, and find one of my hens laying half in and half out of the coop and run entrance. I was able to move her easily, but she began to vomit. She has since passed, but I'm wondering why she died. I now have 2 red rocks, and 1 white leghorn left. None of the chickens looked sick or ill. I'm not sure, but someone told me she could of had a heart attack. It has been extremely hot outside, but there is plenty of room and shade for the chickens to get out of the sun, and water always available. Any ideas?