Chihuahuas are the world's smallest dog breed, typically 3 to 9 pounds, with an apple-shaped head, large upright ears and either a smooth or long coat in nearly any color. They take their name from the Mexican state of Chihuahua, and the AKC registered the first one in 1904. Most are devoted to one or two favorite people and carry themselves with a confidence far bigger than their bodies.
That confidence can come with barking, wariness of strangers and snapping if handled roughly, so gentle socialization and reward-based training matter. Chihuahuas often live 12 to 16 years, so adopting one is a long commitment. They're also among the most common small dogs in shelters, and adults of every age and personality turn up, which makes it easier to find a calm dog who matches your household.