Walter the Farting Dog Farts Again by Wiiliam Kotzwinkle
When Walter the Farting Dog is sold for a measly ten pounds, Billy and Betty are distraught. But Walter doesn't realise he's been caught up in a dreadful plan involving a fake clown, litres of his unique farts and a bank robbery. Only Walter could be relied on to fart his way out of danger as well as solving a bank robbery and becoming the town's hero - even if a bit of a stinky one!