Here you have to pay to get a dog licence and they give you a little tag to go on their collar. Its different to a name tag someone buys and gets their name engraved on.
I would assume it means that without a licence its classed as a stray and you are within your rights to shoot it.
Maybe...
You said they go after anything and anyone. If you start pushing the scared for your own safety angle (or your kids is even better if you have some) you may find that authorities pay more attention than if you are only worried about poultry.
Sad poultry seems to rate so low with people but...