1852

"We have been credibly informed by several gentlemen, familiar with the country of Mexico, that there is a diminutive species of dog running wild, and burrowing in the ground as rabbits, in the neighbourhood of Santa Fe and Chihuahua. 

A gentleman who has seen these animals, states that there is no doubt as to their identity, having met with them in a state of domestication, when they exhibited all the actions and manners of a French lap dog, such as come from Cuba or other West India Islands. 

They are of every variety of hue, and resort to their burrows whenever disturbed in their natural haunts. What they subsist on it is difficult to say, as they are too harmless and insignificant to attack any other animal beyond a mouse or a snail. 

They are represented as being very difficult to tame, but when domesticated show no disposition to return to their former mode of life. 

The lady of the Mexican Minister, when in this city, had one of these dogs as a boudoir pet; it was lively and barked quite fiercely. We have not been able to ascertain whether they bark in their natural state. 

- E. J. Lewis, M.D. 

(Member of the Academy of Natural Sciences of Philadelphia; of the Philadelphia Medical Society; of Parisian Medical Society, etc.

("The Dog". By William Youatt. 1852. Edited, with additions by E. J. Lewis, M.D., p.44)             link