Exo. 21:35-36: If the ox gores another ox, the value of each is divided between the two owners, the dead ox for its hide, and the live ox for full value. If, however, the ox was notorious, then the owner is liable. He has to pay the full value of the dead animal to its owner, but gets to keep the hide for himself. If the law in your town reads that dogs are to be penned or leashed, then your dog is assumed to be notorious because the law said to keep it restrained. If your dog escapes and kills the neighbor's prize winning cat, then you owe the neighbor for the full value of the cat, whatever your neighbor might have gotten on the open market if he had sold the cat alive. But if there is no ordinance requiring dogs to be penned or leashed; then your dog is not assumed to be notorious unless it has a personal history of viciousness. In that case, however, you do not get off scot free, because you lose your dog. The dog must be sold, if it can be, and the money divided with the neighbor whose cat was killed. Thus, you still have some incentive to act responsibly, even if your dog or ox is not notorious.