Jennifer, I'm sorry that this happened to you. I think you were within your rights of killing the dog and I probably would have done the same thing. If it had just been scaring them or gotten just one chicken, it would be different for me, but considering the damage that it did you may have saved many future animals (including human children). Once a dog does something like this it is likely to do it again. Big HUG from your neighbor in Florida! Take your time and find the right sweet chickens to soothe your soul again.