These are the tiniest of all. They are the kind that can easily be carried around or what are known as lapdogs. The pros of these are that they are perfect for people who want to have a dog and live in a small space. The cons are that they are not always peaceful ones. They sometimes get excited or angry easily. Chihuahuas and Pomeranians are known to often do this. include the Chihuahua, Shih Tzu, Maltese, Pekingese and the Pomeranian.