Yesterday two of my dogs killed one of my sweet Light Brahma hens. We put the dogs in the garage but when my mom let them out to go to the bathroom they went after another Light Brahma hen. I had just gotten out of the shower when I saw the dogs run down to the coop. So I chased after them in 29 degree weather. I saved the hen just in time. Why all the sudden are the dogs going after them? We've had one of the dogs around chickens her whole life and the other is a huge german shepherd puppy...did they start cause of her? What can I do about this? I have to let my chickens free range. How do I get the dogs to stop?