zippy- kat Where I live in Ohio no one knows how many dogs you have, they,get this, come door to door looking for dogs. No one has come to my house in years but they used to. Of course I'm on dayturn now so I may miss them. If your dog doesn't bark when they knock on the door then they figure you don't have a dog. If it does they leave a notice to call in your license number. If they catch you without a tag and it's past the date to get them you have to pay double, that's the fine. Mine just cost me $12.75 per dog.
I don't think dogs in shelters have to have them, both of my dogs came from a shelter and they got their tags before they left.