The Chihuahua (Spanish: Chihuahua) is the smallest breed of dog and is so named for the state of Chihuahua in Mexico. Chihuahuas come in a wide variety of sizes, head shapes, colors and coat lengths. The Chihuahua’s history is puzzling and there are many theories surrounding the origin of the breed. Both folklore and archeological finds show that the breed originated in Mexico. The most common and most likely theory is that Chihuahuas are descended from the Techichi, a companion dog favored by the Toltec civilization in Mexico. No records of the Techichi are available prior to the 9th century, although dog pots from Colima, Mexico, buried as part of the western Mexico shaft tomb tradition which date back to 300 B.C. are thought to depict Techichis. Generally, the height ranges between six and ten inches; however, some dogs grow as tall as 12 to 15 inches (30 to 38 cm). Both British and American breed standards state that a Chihuahua must not weigh more than 6 pounds for conformation.