This is the oldest breed on the American continent and the smallest breed in the world. Native to Mexico, where it received its name from the Mexican State of Chihuahua. It was only brought to Europe at the end of the nineteenth century. The Chihuahua is thought to have been derived from the Techichi, a small, mute dog kept by the Toltec people of Mexico as long ago as the 9th century AD. The dogs were sacred to Pre-Columbian Indian nations and were also popular pets to the upper class.

The Chihuahua is a good companion dog. Courageous, extremely lively, proud and adventurous, they enjoy affection. Brave, cheerful and agile, Chihuahuas can be strong-willed and do best with experienced owners. They are loyal and are notoriously one to two people dogs. For some, they may be slightly difficult to train, but they are intelligent, learn quickly, and respond well to proper, firm but gentle training. They can be hard to housebreak.

This breed is generally not recommended for children, not because it is not good with them, but because most people treat the Chihuahua differently than they would a large dog, causing it to become untrustworthy. Because of its size, this breed tends to be babied and things we humans clearly see as bad behavior for a large dog are looked over as cute with a small dog. Small dogs also tend to be walked less, as humans assume they get enough exercise just running around during the day. However, a walk provides more than just exercise. It provides mental stimulation and satisfies the migration instinct all dogs have. Because of this, small breeds such as the Chihuahua tend to become snappish, yappy, protective and untrustworthy with kids and humans they do not know.