Mystery of my Hairless Chihuahua

The Mystery of My Hairless Chihuahua:  Applehead and Deerhead Chihuahuas?

When I got interested in Chihuahuas about 7 years ago, I Googled them a lot.  Practically the first thing I noticed was that people kept asking Chihuahua forums about the “deerhead” as opposed to the “applehead” Chihuahua. The answer was always, “there is no such thing as a ‘deerhead’ Chihuahua;  the AKC only recognizes two types, short hair and long hair”. That is the AKC position. Furthermore, when a deer head type is born to an AKC registered Chihuahua, it’s not likely to be an AKC show dog because it contradicts the AKC standard.


Applehead  Chihuahua      Deer Type Chihuahua        Chip, my 1st Chihuahua     Ruthie, the hairless Chi                                                                                                                                                                              

To help figure out why some chis are deer type and some applehead, and why my new hairless Chihuahua was naked, I started researching the history of pre-Columbian dogs of America for the origins of the Chihuahua. The little known fact is that the ancient Nahuatl and Mayan peoples had at least three distinct dog types.  One researcher counted 17 distinct “breeds” (Jose Payro Duenas, 1981), but these are probably different takes on the three major strains of dogs, so I will look at each of the three major types in the probable order in which they appeared.

The first ancient type of dog is the classic hunting dog type that arrived with their people in Mexico and parts south at least 14,000 years ago, maybe double that and more.  It is a type that occurs all over the Southern and Southwestern US through Mexico, and even down to South America. These southern native dogs looked similar to a larger Basenji (without the wrinkles and the very curly tail,) a Dingo, a Carolina dog type, or even some pariah dogs, all of which tended to be medium size (20-30 lbs)have longish legs and big upright ears, and short  ginger hair. This is a type that has been more or less ignored by foreign dog lovers, unlike other Mexican dogs however, it is still being bred today as they appear in Xolo litters. Nowadays they also get more refined as the hairless ones are bred for refinement.

Hairless and coated Xolos, Coated Xolo

The coated Xolos are the original Mexican hunting dogs. They are littermates. Dog on R is a hairless littermate.

The second type of ancient dog is the Mexican Hairless dog, the Xoloitzcuintle.  (show low eetz kweent-lay or “Xolo” (Show low). These are most likely the second oldest type of dog to be found in the Americas.

One account from a scientific online magazine estimates that the hairlessness was a rare mutation that occurred at least 4,000 years ago, in Mexico only. Very recently, in 2008, Tosso Leeb, a geneticist at the University of Bern in Switzerland discovered information on the mutation that makes Xolos, its variations, and Chinese Crested dogs, bald. According to Leeb, all the bald dogs in the world are from one mutation, in Mexico, at least 4,000 years ago. (link to article)

Both coated and bald dogs occur in every litter with one hairless parent or two hairless parents. I saw a gene chart (but did not note where) that shows the occurrence of dog genes unknown to Asia/Europe in a “clave” of dog genes from Mexico. These genes have not yet been fully explored, yet it seems likely that the dog baldness mutation happened once and because it was an incomplete dominant gene, it was easy to breed offspring for the trait. Compared to Mexico, Central America and parts of South America had fewer concentrations of hairless dogs, but far more than any other area of the world.  No other place in the world had hairless dogs pre-Conquest, even though urban legends about them abound. Standard, Miniature, and Toy Xolos.

ancient pottery xolos.

The one on the left is hairless as the lines stand for wrinkles. The pottery family has a hairless member. These pottery pieces are from 300BC to 300AD

The recipients of the hairless gene were all of a type; the gene stripped the average Nahuatl hunting dog of hair and revealed the grace of the body type as shown in the long legs and, graceful head, the arched neck, and the large ears. Before the hairless mutation, they were originally the typical Mexican hunting dogs with short hair, prick ears and an average but pleasing body type like the gingery Xolo above with a hairless littermate and the black one in the same row. This kind of dog ranging in size small small to medium/large has been found all over Southern America down to South America.  Both the hairy and hairless dogs have been maintained together since the hairless gene first appeared.

Some of these Xolo dogs are currently being bred to Xolo Breed Club specs in a bid to get back into the AKC. (Long Story) They divide the size continuum into three sizes, toy, miniature and standard. This range of sizes is modern because there was no size standard in the old days.  The smallest of the hairless Xolos are often the same type as the short haired deer Chihuahua.

TECHICHI Dogs: The third ancient type of Mexican dog is the Techichi dog, believed to be the parent stock for the modern Chihuahua. You can find this dog in pottery, graves and drawings.

R. Ancient Techichi   Modern cartoon of a modern Chi.  L. Ancient Techichi with funerary mask

When the naked mutation occurred, it is most likely that hairless dogs were interbred back and forth with the standard hunting dogs, just as the Techichi were.  The Techichi was believed to have been a small dog and to bring smaller size into various types of dogs.  It is now recognized that travelers to the New World, perhaps over the Bering Strait and as long as 12,000 years ago brought the small dogs with them. I will go into the genesis of dogs in other posts, but is now thought  that the small dogs came with the immigrants and are of ancient standing.

The modern Chihuahua is reputed to be a direct descendent of the Techichi, an ancient type that had bred true to type since at least 3,500 BPE, and whose history keeps going back further as archeologists uncover more graves and crafts. It seems to have almost gone extinct in Mexico Post-Conquest. There is no direct evidence to connect the Techichis to the modern day Chihuahua, but the consensus is that it was an ancestor to the modern version of the Chihuahua. The ancient Techichi was described as “mute”  and “long haired” several times in the literature. All the pottery I have seen shows short haired Techichi. They are no longer mentioned in Mexico from the 17th -19th century and there are no more dogs that are mute and long haired. (The modern day long haired Chihuahua, went through some  breeding adjustments up to  the 1960’s, and was accepted into the AKC in the 1980’s.) The Techichi itself disappeared in the years after the Conquest. It is believed that over 100,000 were eaten by Spaniards by the end of the 17th century, which is why historians say the border area, the Gadsden Purchase, is the actual source for modern Chihuahua stock.

Woman from Nayarit 300 BC

Tlatico dogs” left is 3,700 years old, the one in the middle is 3,000 years old (Fernandez and Rhae p26)

In modern day Tucson, where there are Chihuahuas on every block, and posters for Chihuahua  puppies at most of the SW side’s main intersections,  your senses tell you that most of the local Chihuahuas  are the deer type and they are usually bigger then than the applehead AKC standard of 4-6 lbs. They tend to run around 10 lbs as adults unless they get fat.  Deer type Chihuahuas are quite good looking, with long legs, a slightly arched neck and the longer, more graceful head, the eyes do not bulge. They often have huge ears compared to the applehead type.  Deer type dogs occur in pottery right along with the little fat Techichis so they too are very ancient, but may not have originally been part of the Chihuahua tribe at all, but rather, Xolo ancestors were at the heart of their “type” as the pottery dogs seem to indicate.

The Chihuahua I ended up choosing had the deerhead and grew up to weigh 10 lbs. His name was Chip. Although Chip had a deerhead, his legs were fairly short. Chip has the longer face and big ears. His eyes do not protrude. He is a typical Tucson Chi, originally from local Mexican stock.  When I started comparing Chip’s face to the Xolo, I jumped to the conclusion that he could have had small, hairy Xolo ancestors’ genes mixed in there with the Chihuahua.

Chip            Ollie           Ruthie

I had mostly ignored the naked Chinese Cresteds until Ollie moved in, in 2008.

Ollie is a powder puff Chinese Crested, the hairy version. I started looking up the breed to see how the breed got bald. According to the AKC legend, Cresties are an ancient breed that traveled on Chinese ships around the world as their vermin catchers. The Chinese were supposed to have left some hairless dogs in Mexico, which degenerated into the Mexican hairless or Xolo. You may have noticed that this version of the origin of Xolos does not fit the facts as I expressed them above.

I found a book on Cresties (written by two long time Crestie breeder/owners, Amy Fernandez and Kelly Rhae) called Hairless dogs: The Naked Truth (1999). This book which quotes earlier writers on hairless dogs makes comments on previous writings about all types of hairless dogs. A lot of debunking takes place about the claims for the origin of the crested breed. The book is also profusely illustrated.

Diego Rivera  + Xolos                      Frida Kahlo + Xolos

Here is the real Chinese Crested story: The authors report that every Chinese Crested in the AKC registry is descended from Debora Wood’s foundation stock of the 1950’s. Wood inherited some hairless dogs from Ida Garrett, probably hairless Xolos or other regional hairless dogs (who have thin, short tufts of very short hair on their heads, feet and end of the tail) and she added a mix of other breeds to get the spectacular crests and feet in her new breed.  An unknown breed, went into the mix of hairless ones until she got this appealing result and then inbred it sufficiently to kind of stabilize the look and qualify as purebred in the AKC. The hairless gene can manifest in Chinese Crested in a range of hairiness from a full but single coat, to dogs with blotchy areas of hair on their bodies, to the perfect Crestie type, to the fully naked throwbacks to the Xolo breeding.  You never see fully naked Cresties in the ring, though you can see a lot of the hairier ones being shaved before being shown. In fact it is rather a scandal, as I write. Unfortunately, almost 60 years of pure breeding have not prevented this range of hairiness, in any way, though a lot of dogs were discarded from the gene pool in the effort to control the range of expression of the gene..

In Wood’s brand new Crestie breed, even the hairy ones were fancy-coated. Wood kept a registry and a few other notable breeders who started with her stock, joined in.  She kept stud books for all hairless breeds. The crested breed was ‘stabilized’ by 1969; nevertheless, it was not registered with the AKC until 1985-1991. Both hairy and hairless types from Wood’s original foundation stock are eligible for AKC, because there are hairy ones in every hairless litter.

The genetics and the history both strongly imply that the Chinese Crested is a fancy inbred variation of the Xolo or maybe the Peruvian equivalent of a Xolo. It is a designer dog, based on Xolo type hairless genes cobbled together with fluff genes, and this no earlier than the 1950’s!

In spite of all the fancy breeding, the CC is nothing more than a variety of xolo and regularly has throwbacks to the true xolo type. My hypothesis at this point in my research has become that the Arizona dogs and the oversized and deer type Chihuahua are basically hairy toy Xolo types with what came to be known as “Chihuahua” genes.  In fact, they are probably offshoots of the original Techichi dogs so common all over Mexico. There is some support for this in the Fernandez/Rhae book.

A Chihuahua legend has it that a very tiny 4-5 lb Mexican fox with enormous ears bred to a Nahuatl hunting dog and produced a very tiny line of dogs. This is pure fancy and absolutely impossible to achieve, as foxes and dogs have completely different numbers of gene pairs.

Or, as is thought today, all dogs originally came from Eastern Africa and the Middle East, where canis lupus was first domesticated.  It so happens that one type of wolf from the area is and was very small compared to full sized wolves and it is highly likely was the original stock from which all small dogs descend. Smallness was originally developed in wolves, but small wolfdogs had some advantages to large ones and were kept from the beginning.  Indeed, after leaving Africa, a huge number of early men and dogs settled in the steppes of central Asia where there were huge herds of animals. After some eons in that area man seemed to have split up and gone in the four directions. The people who went to the far Northeast of Asia eventually crossed the Bering Strait and perhaps used other methods of getting to the New World, their medium and small dogs, with them.


The applehead Chi, like the Chinese Crested, was actually invented in America, starting in the 1850’s in the heyday of new dog breed creation.  It was the Arizona dog with something else mixed in. The breed did not do much until the 1920’s when Ida Garrett who collected small Arizona dogs, (complaining that they did not breed true for size) mixed it up to get tiny dogs similar to the old Techichi pottery types.  The  “Chihuahua” breed made the AKC in 1904. The cute apple head Chihuahua have round heads, protruding eyes, short backs and legs with an upright tail and a little snout that almost looks grafted on a golf ball. The applehead Chihuahuas run from 4-6 lbs. The modern applehead types are stouter in proportion to the deer types, though half the size.  They often have a soft fontanel that never closes. This, to me, along with all the health and genetic problems in the breed shows the breeders including Ida Garrett, ignored the genetic problems as they developed the breed. In the Arizona dogs 8 lbs and over, genetic disease is unknown. As they are not registered, they are not inbred and they are still to be found in Southern Arizona.                                

Jalisco dancing dogs, both hairless               Dancing dogs from Colima  left hairless.                                                                

Ultimately, what we are discussing is genes, not breeds. The nature of the hairless gene is to bring hairlessness to any breed of dog.

GENETICS of baldness. The normal hairy gene is (hh) in 99.999% of all domestic dogs. An incomplete dominant mutation causes hairless dogs (Hh). Only one copy of the H gene is needed. An Hh can be bred to an hh, producing  both hairy and hairless dogs. An Hh can also be bred to an Hh. This combination will also produce both hairy and hairless pups, but the pups that receive a double dose of (HH) never develop. The hh always has hair and would never pass on the hairless gene. The genetics for the hairless Cresties were the same as the other hairless dogs. (The hairless dog story is much more complex than I have described it. Each region from Mexico to Peru had a slight variation of the hairless type.)    We now know the hairless gene can be introduced into any breed or combination thereof, though its traditional home is the Techichi and the Xolo and other hairless breeds from the Americas.

That is why it is a plastic enough gene to roll over into a Chinese Crested and breed true to hairless, no matter what other genes are present. Take a deer type Chihuahua for instance:  breed to a small deer type hairless Xolo (or, in a pinch, you can get the hairless Xolo gene from a Crestie). Out of 4 puppies the odds are at least one hairless pup will result, usually two, rarely three. The rest will look like deer type Chihuahuas. If you breed the hairless offspring back to a deer type chi and breed the hairless offspring of that union to a deer type, you could maintain the hairless gene in a deer type Chihuahua population as long as you breed the naked ones to deer types with or without hair. That is probably a model for exactly what happens in Xolo breeding and the deer type Arizona “Chihuahuas” become the hairy component of the hairless breeding program.

GENETICS  of  size.

Chihuahua and Arizona dog size is controlled by the average of the 6 size alleles of the gene. Every Arizona dog passes on 3 size alleles to its offspring or 6 from both parents. The +1+1+1 -1-1-1 averages out to 0 or average size. More +++alleles makes a dog larger than its parents. More – – – alleles makes the dog smaller. Thus small parents can have a larger pup and larger parents can have a very tiny pup (known as “teacup Chis”)This  gene is much harder to standardize than the hairless one, as Ida Garrett noted.

In summary, modern day applehead type Chihuahuas were invented from Arizona dogs collected in the 1850’s using various other breeds to establish size and type. They are the applehead types that populate the AKC. Deer type Chihuahua are mostly unregistered Arizona dogs, but seem to be the coated descendents of Toy Xolos and/ or the hairy hunting dogs, bred small, probably Techichi influenced. While deer types can be born to AKC Chihuahuas, appleheads are not born to the deer types, unless  the deer types.

The answer to my naked Chihuahua Mystery is: Ruthie is small from the AZ dogs, Bald from the Hh gene obtained from a fully hairy single coated Hh parent, deer type from the original Mexican Techichi dogs. So my Answer is “yes, there are deer type Chihuahuas and this type has little to do with modern AKC Chihuahuas and everything to do with their ancient Mexican breeding.”

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