I don't get it. If you've lived there 6 years, is the dog new or is the guy new, or has this been a 6 year problem? Jode is right if you can get other neighbors to state your dog isn't a problem preferably in writing and video tape him during a normal day, in addition to the dog being listed on you rental agreement, he's out of luck. He knew he was moving into an apartment that allowed pets, if he doesn't like them, then he should have found one that doesn't allow them, those apartments, at least in my area are much more common than pet friendly ones. Sorry, people like him really annoy me.