The creator of my favourite cartoon strip said, “happiness is a warm puppy”. Charles M. Schulz, who gave the world Peanuts and its star canine Snoopy – my childhood obsession (I had that cheeky black and white beagle plastered on T-shirts, socks, mugs, pencil cases, paperweights, the lot) – understood the power of a cute and clever pet. A pet that picks up on emotions, instinctively knows when you're sick, entertains with its peculiar ways and melts your heart with its doleful eyes. A pet that seems to love you, no matter what. And then there are dogs that do more than just be your friend. This week, animal lover Leisa Scott meets some very impressive canines dramatically improving the lot of the humans they serve. Prepare to be amazed. We also talk to Australia's star swimming sisters Cate and Bronte Campbell who, ahead of the Commonwealth Games in Scotland, reveal for the first time the person who is their greatest inspiration.