Xoloitzcuintlis were thought to cure rheumatism because their body heat lessened the pain caused by the condition. Ground dog bone mixed with food was thought to cure disease and protect the patient from evil spirits. Xoloitzcuintlis standing next to the door were also thought to protect against evil spirits. Priests used the slime from dogs' eyes to see the dead and gods of the underworld, and their blood was reputed to revive the dead, bestow clairvoyance and permit communication with heaven. The Itzcuintli was the tenth sign of the days and was associated with lightening or celestial fire.
Dogs also appear as central figures in several myths.
In one, the sun courts a woman and then turns her into a dog. The cosmic sun Chalchiuhtonatiuh ended when a rain of fire swept men away, turning some into dogs. It was also believed that human beings had been born in a cave of a woman impregnated by a dog. The most fortunate has been the Xoloitzcuintli , which has survived until today and is considered a rare, special breed. The Tlalchichi probably became extinct in the Colonial Period, but it is possible that it changed constantly over the years and became the Mexican Chihuahua.