#3 Chihuahua

The American Kennel Club (AKC) registers the Chihuahua as the smallest breed of dog and believes it to be the world’s tiniest dog. Their typical weight is between four and six pounds, making them part of the “toy” breed of dogs. Their coloring might be uniform, marked, or splashed, and they can have hair that is either short or long and of almost any color.

Although they are mainly one or two-person pets, chihuahuas are incredibly dedicated to and loyal to their owners. They can be too loyal to the point of jealously and may bite or snap at others who approach their owner too closely. They are infamous for being extremely temperamental and not being particularly kid-friendly. They typically dislike strangers, which causes them to bark frequently and work well as vigilant “watch dogs.”