Chihuahuas are the smallest breed of dog recognized by certain kennels, growing to no more than 9 inches in height and weighing up to 6 pounds. Although diminutive, the Chihuahua is a bold, lively breed that can be difficult to train if its owner is not resolute enough.
Chihuahuas are named after the Mexican state of Chihuahua, where the breed likely originated. Due to their large heads, it is sometimes difficult to diagnose hydrocephalus in young Chihuahuas. Cesarian section is also not uncommon in Chihuahuas, as the birth canal has a difficult time passing the head of the puppy. Chihuahuas are ideal dogs for apartments but still require walks.