Chihuahuas take their name from the Mexican state of Chihuahua, where small dogs of this type were described in the 1800s. The AKC registered its first one in 1904. The show standard calls for under six pounds, though many pet Chihuahuas weigh more. Look for a rounded, apple-shaped head, large upright ears and a smooth or long coat in almost any color.
These dogs are confident, alert and closely attached to their people. That can mean barking, wariness of strangers or snapping when handled roughly, so gentle socialization matters. House-training can take patience in toy breeds. Chihuahuas vary a lot, and adults of different ages and personalities are common in shelters nationwide, so meeting the dog in front of you tells you more than the breed label.