The Chihuahua is the smallest breed of dog and is 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 BC are thought to depict Techichis.
It is probable that earlier ancestors were present prior to the Mayans as dogs approximating the Chihuahua are found in materials from the Great Pyramid of Cholula, predating 1530 and in the ruins of Chichen Itza on the Yucatán Peninsula. Chihuahuas are very small dogs, and are the smallest breed recognized by some kennel clubs. There are two main varieties recognized by kennel clubs, the short-haired and the long-haired.
There is a second varietal split as well, having to do with the shape and size of the dog's head. These two descriptive classifications are "apple head" and "deer head", but only the apple head is conformationally correct. Breed standards for this dog do not generally specify a height; only a weight and a description of their overall proportions.
The temperament of its human guardian can make a difference in the temperament of the pup. Tempered Chihuahuas can be easily provoked to attack, and are therefore generally unsuitable for homes with small children. The breed tends to be fiercely loyal to one particular guardian and in some cases may become over protective of the person, especially around other people or animals.