The Xoloitzcuintle (/zoʊloʊ.iːtsˈkwiːntli/ zoh-loh-eets-kweent-lee), or Xolo for short, is a hairless breed of dog, found in toy, miniature and standard sizes.The Xolo also comes in a coated variety and all three sizes can be born to a single litter. It is also known as Mexican hairless dog in English speaking countries, and is one of several breeds of hairless dog.
In Nahuatl, from which its English name originates, its name is xōlōitzcuintli [ʃoːloːit͡sˈkʷint͡ɬi] (singular)[1] and xōlōitzcuintin [ʃoːloːit͡sˈkʷintin] (plural). The name xōlōitzcuintli comes from the god Xolotl and itzcuīntli [it͡skʷiːnt͡ɬi], meaning dog in Nahuatl.
A genetic study was recently conducted in order to determine the origin of the Xoloitzcuintli breed. The study did not find a close genetic relationship between Xoloitzcuintli and the Chinese Crested Dog. However, the study showed that this breed did not result from a separate domestication of dogs in the New World. Xoloitzcuintli appear to have been a result of a mixture of several Old World dog breeds.
The breed ranges in size from about 10 to 50 lb (4 to 20 kg). Similar in appearance to a Pharaoh Hound, with a sleek body, almond-shaped eyes, large bat-like ears, and a long neck, the Xolo is notable for its dominant trait of hairlessness. The dominant hairless trait originated in this breed as a spontaneous mutation thousands of years ago. The recessive expression of the trait will produce a coated variety, which is genetically inseparable from the hairless, as the homozygous appearance of the hairless mutation is fatal to the unborn pup. Most litters contain both hairless and coated puppies. The coated variety, covered with a short, flat dense coat represents the original form of the dog, prior to the occurrence of the spontaneous hairless mutation. The hairless variety is completely hairless on the body, with many dogs exhibiting a few short hairs on the top of the head, the toes and the tip of the tail. Most hairless dogs are black or bluish-gray in color. The allele responsible for the Xolo's hairlessness also affects the dog's dentition: Hairless Xolos typically have an incomplete set of teeth while the dogs of the coated variety have complete dentition.
The Xolo is moderate in all aspects of its appearance, conveying an impression of strength, agility and elegance. Xolo body proportions are rectangular, slightly longer in total body length than the height measured at the highest point of the withers (top of the shoulders). The breed occurs naturally in two varieties, hairless and coated. Hairless Xolos are the dominant expression of the heterozygous Hh hairless trait.Coated Xolos (hh) are the recessive expression, and breeding hairless to coated or hairless to hairless may produce pups of either or both varieties. Breeding coated to coated will only produce coated pups because they are recessive to the hairless trait and do not carry the dominant H gene.
Both varieties occur in all hair or skin colors, and often marked, splashed or spotted. The most common colors are various shades termed black, blue, and red. The breed occurs in a range of sizes, which breeders have standardized into three designations.
source : wikipedia