What's a Belly Band?

Just heard that the KC have concerns about the misuse of belly bands, I'd never even heard of them before then. What are they, what are they meant to be used for and how could they be abused?
Sarah Stevens, Slough

A Belly Band seems to be an American invention - it's a wrap secured by velcro that goes around a male dog's middle stopping them weeing or even mating! Correctly used they stop dogs from scent marking - particularly useful for hard to housetrain dogs or dogs that may be incontinent. Incontinence pads can be used inside the wrap. The KC are worried about these wraps being too tight or being left on for too long.