Laws differ from county to county & country to country. Here in Panama, a chicken killing dog (or any other livestock killing dog) is a dead dog. Period. Folks 'round these parts won't put up with a dog like steals the food off of the dinner table, or livestock, as that is seen as our future dinner. It's commonplace for folks here to let their dogs 'run', it's uncommon to have issues with 'bad' dogs.