Documentary charting the lives of four puppy litters in intimate detail, from birth to their sixth month. Owners and breeders join vet Mark Evans as he sheds light on what to expect from these young chihuahuas, sheep dogs, rescue puppies and assistance dogs as they grow into maturity. In the first of two programmes, cameras follow the pups during their first eight weeks of life, which include such milestones as opening their eyes for the first time, taking their first steps, and developing the crucial skill of `bite inhibition'.