September 18, 2026
When people first look inside the mouth of a Hairless Xoloitzcuintli, they often have the same reaction:
“Where are all the teeth?”
And then come the questions.
Why does one Xolo have more teeth than another?
Why can a puppy have a complete-looking set of baby teeth but later have fewer adult teeth?
Why can some teeth be crooked?
Why can the bite change as the dog matures?
Why can some Xolos lose teeth later in life?
The answer begins with genetics.
The dental system of the Hairless Xoloitzcuintli is closely connected with the same genetic mechanism that produces hairlessness — particularly the FOXI3 gene. Research has shown that the FOXI3 variant associated with hairlessness also affects dental development, including the number and morphology of teeth.
This is why the teeth of a Hairless Xolo should not always be evaluated in exactly the same way as the teeth of an ordinary dog.
The Xoloitzcuintli has two coat varieties: Hairless and Coated.
They are the same breed, but their dental patterns can be different.
The Coated Xolo normally has a complete dentition.
The Hairless Xolo can have an incomplete dental formula. The FCI standard specifically recognizes the particular dental characteristics of the Hairless variety and states that a complete set of incisors is preferred.
This means that when we talk about missing teeth in this article, we are primarily talking about the Hairless Xoloitzcuintli.
This brings us to FOXI3.
FOXI3 is involved in the development of ectodermal structures, including hair follicles and teeth.
The genetic variant associated with Hairlessness can therefore affect both the skin and the dental system.
Research in Hairless dogs has documented missing permanent teeth, including premolars, canines and some incisors, as well as changes in the morphology of certain teeth.
This is why the dental formula of a Hairless Xolo can vary considerably from one individual to another.
And this is also why a future owner should understand that missing teeth are part of the genetic picture of the Hairless Xolo — not automatically a sign of poor care or disease.
This is one of the most important things for Xolo owners to understand.
A puppy may have a beautifully developed set of baby teeth.
But this does not guarantee that every corresponding permanent tooth will eventually appear.
In other words, if you can see a baby tooth in a particular position, you cannot automatically assume that a permanent tooth will later replace it.
In Hairless Xolos, some permanent teeth may never develop.
This is why the number of baby teeth seen in a young puppy cannot be used as a guarantee of the final adult dental formula.
The puppy's mouth is still developing, and the permanent dentition may look very different once the tooth-changing period is complete.
A puppy's mouth goes through several stages.
First come the deciduous, or baby, teeth.
Then the teeth begin to change.
During this period, the mouth can contain:
Therefore, the dental picture of a young Xolo can change significantly over several months.
This is particularly important when evaluating a Hairless Xolo puppy.
The number of teeth you see at one age does not necessarily tell you exactly what the adult mouth will look like.
The answer again comes back to the genetic characteristics associated with Hairlessness.
FOXI3 affects tooth development, and the expression can vary between individual dogs.
Scientific studies have documented missing permanent premolars, canines and incisors in Hairless dogs, as well as morphological differences in some teeth.
Therefore, the real dental picture of a Hairless Xolo can be very individual.
One dog may have a relatively complete set of teeth.
Another may have several missing teeth.
Both can still be Hairless Xolos with a dental pattern related to the genetics of the variety.
This distinction is extremely important.
The bite describes how the upper and lower jaws relate to each other.
The position of an individual tooth is a different matter.
A Xolo can have teeth that are rotated, tilted or positioned irregularly because of the structure of its dental arch and the number of teeth present.
That does not automatically mean that the dog has an incorrect jaw structure or an incorrect bite.
The FCI standard requires the jaws to be strong and describes the acceptable bite, while also specifically addressing the special dental characteristics of the Hairless variety. Prognathism, enognathism and a clearly poor bite caused by incorrect jaw positioning are disqualifying faults.
So we should not judge the entire bite simply because one tooth is crooked.
When evaluating a Xolo, we need to look at:
jaw structure → relationship between the jaws → bite → function → individual tooth position.
Imagine a dental arch in which several teeth are missing.
The remaining teeth have more space around them.
As the dog matures, individual teeth can therefore change their position.
In our experience with Xolos, a tooth that appeared relatively well positioned when the dog was young can later become more tilted or rotated.
The overall appearance of the dental arch can also change.
This is another reason why we do not evaluate a Xolo's dental quality based only on whether every individual tooth looks perfectly straight.
The structure of the jaws and the functional bite are much more important.
Yes.
Some Xolos can lose teeth later in life.
In our experience, tooth loss may become noticeable in some dogs around 6–8 years of age, although this is not a rule and certainly does not happen to every Xolo.
Some dogs maintain a very good dental system well into old age.
The reason for losing an individual tooth can also vary. Dental disease, periodontal problems, tooth structure, trauma and other factors can all be relevant.
Therefore, a tooth that becomes loose or falls out should not simply be dismissed as “normal for a Xolo.”
It is worth having the dog's mouth evaluated.
This is another situation Xolo owners may encounter.
Sometimes a deciduous canine remains for much longer than expected.
A puppy may even appear to have two canines in the same position — the baby canine and the permanent canine.
There can also be another situation: the baby canine remains, while the permanent canine never develops.
In a Hairless Xolo, the permanent tooth may simply not have formed.
However, owners should not decide themselves whether a retained baby tooth should be removed.
A veterinary dental specialist should evaluate:
The correct decision should be made individually.
This can happen when the permanent tooth itself has not developed.
If there is no permanent tooth bud, there is nothing that can erupt after the baby tooth is lost.
This is another reason why Hairless Xolo dentition cannot be interpreted according to the assumption that every baby tooth must eventually be replaced by a permanent tooth.
The genetics of Hairlessness can influence the development of permanent teeth.
With Xolos, it is important to evaluate the jaws and the functional bite, rather than simply counting teeth or looking at whether every tooth is perfectly aligned.
The current FCI standard allows a scissor bite and also an edge-to-edge bite. It specifically states that a complete set of incisors is preferred in the Hairless variety.
For us, this means that when evaluating a Xolo, we look at the whole picture.
A single crooked tooth should not automatically define the quality of the dog's bite.
The jaw structure comes first.
Then the relationship between the jaws.
Then the bite.
And only after that do we assess the position of individual teeth.
The fact that some missing teeth are accepted in the Hairless Xolo does not mean that a breeder should stop caring about dental quality.
Quite the opposite.
At Sine Metu, we deliberately pay close attention to the dental system when evaluating breeding dogs and planning pairings.
Our goal is to preserve the best possible dental development in Hairless Xolos and to encourage stronger dental formulas in future generations.
Yes, the breed's genetics mean that a Hairless Xolo can have missing teeth.
But responsible breeding does not mean saying:
“It is allowed by the standard, so it doesn't matter.”
We want to work toward the opposite.
We select dogs with strong dental systems whenever possible and consider dental characteristics when planning future breeding combinations.
Our goal is not simply to produce a Hairless Xolo.
Our goal is to produce a healthy, well-structured Xolo with the strongest dental system possible within the genetics of the Hairless variety.
And even with careful selection, nobody can guarantee the exact dental formula of every future puppy.
Absolutely.
Having fewer teeth does not mean that the remaining teeth do not need care.
Quite the opposite.
Regular oral hygiene should be part of a Xolo's normal life.
Home care includes regular tooth brushing with dog-specific toothpaste and an appropriate toothbrush.
But home brushing does not replace professional dental examinations.
We recommend having the mouth checked regularly by a veterinarian and arranging professional dental cleaning when clinically indicated.
For many dogs, an oral examination at least once a year is a sensible routine. Older dogs or dogs with existing dental problems may need more frequent monitoring.
The answer depends on how many teeth remain and how well they function.
If an eight-year-old Xolo still has a healthy functional set of teeth, there may be no reason to change the dog's normal food simply because of age.
If the dog has lost many teeth and chewing becomes difficult, the diet can be adapted.
For example, dry food can be softened with water or a different food texture can be considered.
If very few teeth remain, nutrition should be assessed individually.
For an older Xolo, I recommend discussing both dental health and nutrition with a veterinary dentist and, when needed, a veterinary nutrition professional.
The important question is not simply:
“How many teeth are left?”
It is:
“Can my dog comfortably eat, chew and maintain good nutrition with the teeth that remain?”
If you look inside the mouth of a Coated Xolo, you may see one picture.
If you look inside the mouth of a Hairless Xolo, you may see something very different.
And that difference is part of the breed's biology.
A Hairless Xolo may have:
But this does not mean that every Hairless Xolo will have all of these characteristics.
Every dental system is individual.
A Hairless Xoloitzcuintli is not simply a dog without hair.
The genetic mechanism that creates the characteristic Hairless phenotype is also connected with dental development.
That is why the dental system of a Hairless Xolo can look so different.
For the owner, the important thing is to understand the difference between a breed-related dental characteristic and a genuine dental problem.
A missing tooth associated with the genetics of Hairlessness is one thing.
Pain, inflamed gums, heavy tartar, a loose tooth, a problematic retained baby tooth or difficulty eating are something else.
Good dental care means understanding the genetics, monitoring the mouth, maintaining hygiene and involving a veterinary professional when something looks abnormal.
A Hairless Xolo does not have to have 42 teeth.
The number of baby teeth does not guarantee the number of permanent teeth.
The dental characteristics of Hairless Xolos are connected with the genetics of Hairlessness, including FOXI3.
A crooked tooth and an incorrect bite are not the same thing.
Not every missing tooth is a disease.
A retained baby canine should be evaluated by a veterinary dental professional.
Xolo teeth still need regular hygiene and veterinary monitoring.
Some Xolos may lose teeth as they age, and their diet may need to be adapted depending on their remaining teeth and ability to chew.
And perhaps most importantly:
We cannot change the genetics of the Xolo. But we can work with those genetics responsibly.
This is why dental development is an important part of the Sine Metu breeding program.
We do not simply want to preserve Hairlessness.
We want to preserve the best possible dental system together with health, structure, temperament and breed type.
Is a mono-breed Miniature Xolo kennel.
We know everything about the Xolo breeding and even more.
We choose only the best Xolo bloodlines in the world for the breeding purpose in our kennel.
Our graduates live in more than 15 countries in Europe, the USA and Canada.
All our breeding dogs get tested for genetic diseases and are in excellent health condition.
