Although the Xoloitzcuintli is still considered rare in the US, and not yet fully recognized by the American Kennel Club or AKC, this dog breed is enjoying a surge of popularity among enthusiasts of small dogs. Xoloitzcuintli dog breeders hope that this favorable public interest will help maintain the breed line of one of Mexico's most ancient canines. In fact, the Xoloitzcuintli is the official dog of Mexico.
This dog breed is recognized in three distinct sizes, namely, standard, toy, and miniature.
According to the FCI or the Federacion Canofila Mexicana (Mexican Kennel Club), the accepted conformation of a standard Xoloitzcuintli is as follows: the height of the dog is approximately between 20 to 30 inches or 51 to 76 centimeters tall at the withers and its prescribed weight is between 25 to 40 pounds or 11 to 18 kilograms.
There have been reports of standard Xoloitzcuintlis that garner more than 60 pounds (or more than 27 kilograms) in weight, but these "heavier" dogs are either considered genetically rare or medically obese. Both cases are often classified as "undesirable" in the Xoloitzcuintli dog breed conformation. Since a standard Xoloitzcuintli is known for its sleek body shape, a heavy Xoloitzcuintli looks somewhat disproportionate. A medium build is accepted in the conformation standards as long as the Xoloitzcuintli still exhibits grace in movement and presents a strong, clean stride. Some standard Xoloitzcuintli dogs that are within the prescribed weight, yet show extremely narrow bodies with very short legs, are likewise considered "undesirable" and disqualified from conformation standards.
Being the largest among the three sizes, the standard Xoloitzcuintli shows more aggression towards strangers when compared to its toy and miniature counterparts. Although not overly antagonistic towards strangers, the standard Xoloitzcuintli is perhaps the best guard dog among the three. This fact does not, however, rule out the extreme alertness and sudden ferociousness of the toy and miniature Xoloitzcuintli.
The Federacion Canofila Mexicana also lists the accepted conformation of a toy Xoloitzcuintli. Its conformation is as follows: height is approximately between 20 to 30 inches or 51 to 76 centimeters tall at the withers and its weight is between 25 to 40 pounds or 11 to 18 kilograms.
There is a slight confusion in regards to this classification. The Xoloitzcuintli dog of this size is often called 'toy Xoloitzcuintli' in the US. On the other hand, Mexican dog breed enthusiasts list it as 'miniature Xoloitzcuintli'. The miniature Xoloitzcuintli conformation dictates that its height should be between 15 to 20 inches or 38 to 51 centimeters tall at the withers. Its weight should be between 15 to 30 pounds or 6.8 to 14 kilograms.
As with the toy classification, the "miniature Xoloitzcuintli" in the US is called by another name in Mexico. The official classification is "intermediate Xoloitzcuintli".
Although history showed that the Xoloitzcuintli breed has been in existence since the time of the ancient Aztecs, the standard Xoloitzcuintli and the miniature Xoloitzcuintli were only officially registered in Mexico in the year 1955. The toy breed was registered only at the turn of the century.