Many of us like the idea of a guard dog who helps to keep the house safe. What better deterrent from criminals than a big, scary guard dog with a booming bark? But at the same time, we live busy lives. We want a guard dog who can hold down the fort while we’re gone or sleeping, but who will also happily accept family and friends in the home, cuddle with our nephews, and politely greet strangers on walks. Here's how to do it.