In the great white north, you are allowed to protect your livestock.
also the laws around dogs are very simple up here. My dog is not friendly to other dogs, so by default I have had to learn the rules. when my dog is "confined" to my property, and a stray animal comes to visit.... its not my problem. If my dog gets loose, and attacks another animal it is my problem. if I take my dog for a walk, I am responsible to keep my dog under control, however if a loose dog approaches us, and I try to prevent an altercation... then still not my problem.
I love dogs, but i would not hesitate to protect my livestock from a dog that repeatably terrorizes.
ask a few neighbors... tell them your story... if they cant be bothered to tie up they're dogs... then oh well.