Both the Mexican hairless and Chinese crested are sold as hypoallergenic dogs, yet neither is hairless or truly allergy-free. Thin, sparse hair on the dog's head and tail are common in the Mexican hairless -- technically known as a Xoloitzcuintli. Long hair flows from the Chinese crested's head, lower legs and tail. Amount of hair isn't all that sets the dogs apart, as differences extend to their personality, build and care requirements as well.
Let's Get Physical
Xolos come in three sizes -- toy, medium and standard. A toy Xolo may only be 10 inches at his shoulder while a standard can stand about 2 feet. Weight ranges from 9 to 30-plus pounds, with life spans ranging up to 14 years. Chinese cresteds come only in one size and stand 11 to 13 inches at the shoulder. Cresteds come in a mostly hairless variety with a plumed tail, hair on the head and "bell-bottoms" on the legs. Both dogs come in a variation with hair. Powderpuff cresteds have a soft double coat and the hairy Xolos have short, smooth fur.
Chinese crested dogs are notoriously sweet-tempered with a carefree and happy attitude. They do well in families with children, providing the kids are well-mannered with dogs. The crested is friendly towards strangers, making him a good dog for social situations. The Xolo tends to be tranquil and calm, needing only moderate exercise. His protective and attentive temperament makes him a good guard dog. Xolos do well with other pets and children. He is somewhat suspicious of strangers and doesn't like unfamiliar people touching him.
While the hairless versions of both dogs are prone to sunburn, the Chinese crested is more prone to skin irritation, sunburn and allergies. The dark skin color of the Xolo gives it more protection against the sun because of increased melanin, but you'll still need to use sunscreen on him. Both breeds are prone to acne and hairless varieties need their skin wiped daily to remove dirt in addition to weekly baths. Both shed less than most dogs and come recommended by the AKC for people with allergies.
Exercise and Fencing
Both the Mexican hairless and Chinese cresteds need to be indoor dogs. Cresteds have a reputation for being hard to house train, but can be taught to use a puppy pad or litter box. If you want him to go in the yard, you'll need to be diligent about regular trips outside. Don't leave him alone in the yard until you are sure it is escape-proof, as cresteds are excellent climbers. Xolos like being with their people at all times and become destructive when left alone for long periods. He becomes depressed when boarded or left in the care of anyone but his own human beings. He is easily house-trained and adapts to new settings as long as he can stay in the company of his people.