GardenersCardiff answers:

I feel badly for the dog. You have done your neighborly duty in nicely requesting the dog remained leashed in addition to providing proof. You could spray the dog with a hose and say “go home” since you can’t get help from you neighbor. Additionally, you can call the dog officer or ASPCA for methods to handle it. You can also call the police because if there is a leash law in effect in your town, then it is the responsibility of the dog owner to keep him contained. If the neighbor disregards the police several times, the dog will be removed from the neighbor, forcing him to pay a fine and answer to animal enforcement. There will come a point when the man will not be able to get the dog back. So sorry to hear of your troubles and I hope you can peacefully find resolution soon.