BBC Scotland investigates the multimillion pound world of the dog trade. A third of all dogs bought today are believed to have come from puppy farms. Using secret filming, reporter Sam Poling follows the supply chain, from the small-time illegal sellers to the profit-driven puppy farmers getting rich off this ruthless trade. She exposes Scotland's biggest dog trafficker and uncovers a breeding facility operating on a scale the experts didn't believe existed in the UK - until now.
