My viewpoint is that I do not agree with killing a dog if it's attacking my chickens, BUT I will do anything else besides that to get that dog away such as hurling rocks at it and hitting it with a stick and screaming at it. Sounds intense and dramatic but hey, anything other than k*lling a dog. But if it's a dog that is attacking me, that's a different story. If it's any animal that's hurting my chickens, I will not kill it. I will try to prevent the animal from getting to my chickens in the first place....If your coop is already not predator proof, then you are already setting animals up for failure. If it gets to your chickens consider it YOUR fault (and I'm not focusing this to the thread starter, I'm just saying you as in anyone who is reading this

.) Maybe you could have prevented it by burying chicken wire or something similar underneath the perimeter of the coop, or maybe if you care about your chickens that much you should even go to the extent of surrounding your yard in electric fencing. Again, not focused to anyone specific, just stating my thoughts and views to everyone.