On the other hand we have breeds like the chihuahua where there really is no way of knowing what they were before they were chihuahuas. The only thing we have to tell us what went on with the techichi is a handful of journals from Cortes, who is um… probably not the most accurate source considering everything. The native people who owned them first have been systemically all but wiped from existence thanks to the Spanish genociding them off the face of the map and the few left often want absolutely nothing to do with their colonizers which, super fair. So all we have is what Mexico has decided they should be, and to try and stay true to that.
Cortes said the Aztecs kept them in hutches and ate them like rabbits, he did not consider them dogs until he got a good look at one. The dog he describes is yellow in color, with short coat and large upright ears. His drawings depict a dog that closely resembles what would be a toy xolo, coated. He later describes a larger dog that can be hairless or coated- which is probably more accurately a xolo. This is why it can be hard to tell exactly where “chihuahua” (techichi) and “xolo” split in Mexican history, since without those who invented the breeds to tell us we’re left to make our best guesses based on what evidence we find.
These are all Xolos, not chihuahuas or chihuahua mixes. The top two photos are from xolo rescue- so it is possible they are not purebred- while the bottom is from a breeder’s page to use as an example of coated vs hairless. This is why describing “small, primitive, terrier-type dog originating in Mexico” makes it incredibly hard to tell where the chihuahuas’ ancestor ended and the coated xolo began. In this modern day, purebred and papered chihuahuas even in Mexico bear little genetic resemblance to the Xolo (most of them are related to small breeds coming from various parts of Asia, or to the line of ancient wolf that proliferated everywhere around the world), where a lot of “deer head” (terrier head) chihuahua specifically are closely related genetically to the Xolo. This tells us that at some point the breeds may have been indistinguishable from each other, and that any chihuahua that does not bear the classic apple shaped head is likely not a purebred chihuahua.
In any case at some point they were used as circus dogs, animal actors, and street performances, so a chihuahua in theory should be relatively obedient. I would also argue they should be relatively social- considering they as feral dogs allowed people to catch and interact with them- and should be terrier-like but not wholely terrier in attitude, which would contribute to how they survived for years without human intervention.
The Mexican standard describes them are spirited, happy, peppy little dogs with some saucy expressions and a little bit of standoffishness towards other dogs which can include barking at another dog as a challenge. However it also says they should not follow through on the challenge- if the situation escalates to fighting a proper chihuahua should attempt de-escalation before fighting. This also makes sense for a feral dog- issuing a challenge is one thing but fighting is costly and aggression can cost you your life, best to avoid a true confrontation and rely on bluffing to get your way. They should be clannish, vastly preferring similarly sized/shaped dogs and specifically other chihuahuas, which again makes sense if you’re an absurdly tiny dog trying to survive by yourself in Mexico wilderness or on the streets.
And they should be totally obsessed with their owners, this is something repeated throughout what we do know of the breed’s history that they should love their owners more than they love anything else. This I find interesting as I would say most primitive dog breeds are intended to have that unwavering loyalty. Something about how we domesticated the first dogs must have highly favored the packbond one would have with a dog like this, for a lot of these original dog breeds to be so dedicated to their one person or their family.