This morning I noticed 2 of my best layers were missing. One was never found, not a feather or drop of blood anywhere. The second was laying on her side. I saw no bite marks or signs of struggle, but her intestine were hanging out of what looked like her hatch. She had recently died. There were a few feathers around her, and what seemed to be a small amount of thick bloody mucous. I keep my hens in a free range area fenced off from the area my dogs are in. Beside us and behind us are fenced yards with dogs. We live in the Mojave Desert, with lots of sand, but their area has several trees for shade and roosting. Their nesting boxes are kept against a small storage shed to protect from wind. I have not seen any predators, nor have I had any problems before. Do you have any idea what could have killed my chickens?