I know our HS in our city if they pick your dog up even with a tag, if your dog is not neuter/spayed you pay a hefty fine. Even though when you purchase the tag and tell them your dog is unaltered, you pay a huge price for a tag for an unaltered dog to begin with, if they find your pet you pay. You also pay more if its a female in heat running at large with a tag, they will release the animal to you after the fines even if it is still not fixed.
My neighbour a few houses down has a female that is intact, and the HS cruises the neighbourhood looking for her in the spring. Its like they know she will be running. He has paid over 300 dollars each time to spring her from the pound but still refuses to get her fixed
