Martin Clunes explores the ancient ancestry of domestic dogs, and explores why they have worked so well with humans for so many years. He begins by looking at different types of dog, including a rat-catcher in Kent, entrants in an Earl's Court dog show, and a singing dingo in the Australian outback, and reveals how dogs are almost identical in their genetic make-up to wolves. How many wild and untamed instincts still lurk inside the millions of dogs which are born every year?

Martin Clunes explores the ancient ancestry of the domestic dog, examining why their relationship with man has worked so well. Today, he seeks to understand why the link between man and beast has survived over centuries, despite the relative redundancy of a dog's primary importance to its owner. He also looks into the terrible, hidden price pets pay for generations of pedigree inbreeding.