I love dogs. I am continuing to learn about dogs, day by day.
I used to be confused when reviewing the different breed descriptions when they would refer to a seemingly small and harmless dog as a good Watch Dog. This is because I didn't understand the difference between a Watch Dog and a Guard Dog.
Watch dogs are bred to alert the owner of an intruder or other problem. That's it. They bark to wake you up, then YOU deal with it. Guard Dogs, on the other hand, are bred to protect the property of the owner, whether the owner is present or not.
And so now it makes perfect sense to me how a Shih-Tzu can be an excellent Watch Dog.
This also helps me to understand how my "gentle giant" 225 pound English Mastiff stands behind me when he barks. He is a watch dog, not a guard dog. He barks really loudly, but he saves the biting for me. We'll see how he acts when he grows out of his puppy stage.