A few years back there was a story broken by one of the daily papers about the training methods that the police were using in this country. It was alleged that handlers were urged to hit, kick and hang their dogs on their check chains.
National outcry ensued and the police reviewed, revised and even televised their new selection and training methods.
Is your neighbours dog a working police dog?
Have you tried calling into his workplace and speaking to a higher ranking officer? If you do try to mention public image as often as possible and the number of people who are members of the public that have seen him abuse his dog and found their image of the police lowered because of it.