Maybe before actually reporting him, "threaten" him. You do not have to do it in a mean way, just tell him nicely if something does not change that you have to call animal control about it.

Some may remember my constant posts about my neighbor's Pit Bull, Buddy, digging under the fence coming to play with my dogs. I wouldn't have mind that he came over besides the fact that he was giving my dogs fleas constantly. I would come home and he'd be sitting at my sliding glass door. He was the sweetest thing, just wanted to be loved and to play, but I had school and my own dogs to take care of. I didn't have time for him everyday.

Anyways, we talked to his owner and since then we have not had problems with him digging under the fence. I'm not sure what they did, as we still see Buddy in the yard a lot, but he has not dug in a LONG time.