Getting to the Bottom of Tan Points in the Cane Corso

Words matter. And never is this truer than in a breed standard, where misinterpretation of phrases and even individual words can have unintended consequences.

Consider the color disqualification in the AKC Cane Corso standard:

“Any color with tan pattern markings as seen in black-and-tan breeds.”

What exactly does that mean, and how should it be interpreted in fawn and red dogs that appear to have lighter-colored tan points on their legs and cheeks?

Color Me Confused

First, a nod to reality: Few, if any Molosser breeds have as many oddball colors — that is to say, colors not addressed in the standard — as the Cane Corso.

The reason for all this, uh, diversity is that some breeders of the past — in both North America and Europe — played fast and loose with pedigrees. All kinds of outside breeds were folded into Corso bloodlines: Boxer, Bullmastiff, Dogue de Bordeaux, Great Dane, Neapolitan Mastiff, Maremma, Presa Canario, Rottweiler — you need an energy drink just to get through the list, and I’m sure I’m missing some. Many of the foreign colors and patterns that today are so plaguing Corso breeders — and turning into “fad” colors, such as straw — arguably result from these crosses.

And that brings us to the disqualification in the AKC standard. It is no secret that Rottweiler blood was used to augment the Cane Corso gene pool, particularly in North America. (In fact, there are those who argue — convincingly — that the founding American lines were based on nothing less than a Neo/Rottie cross.) Before the Corso was AKC recognized in 2010, black-and-tan and gray-and-tan Corsos were seen regularly in the rare-breed rings, with some even gaining their championships.

Indeed, the black-and-tan pattern is so pervasive in Corsos that some studies show its frequency in the breed to be a whopping 25 percent; in other words, one-quarter of all the alleles on the A locus in Corsos are at, which can produce black-and-tan. (The presence of dominant black in the breed camouflages this pattern, which may be why the former was so popular for so many years in Europe: It hides a multitude of sins.)

Why, then, isn’t the color disqualification written more directly? Something like: “black-and-tan pattern, as seen in a Doberman or Rottweiler”?

Two reasons: First, the American Kennel Club does not permit other breeds — or even other animals, for that matter — to be mentioned in standards. The reason for this is that breeds change over time, and similarly, different animal species vary from region to region. So the vague-sounding “as seen in black-and-tan breeds” was intended to refer to the very specific pattern seen in the Doberman or Rottweiler: tan markings above each eye; on the muzzle, throat and forechest; on all four legs and feet, and below the tail.

There are several variations on the black and tan pattern, including red and tan, seen above, as well as blue and tan (below left) and Isabella (below right), sometimes referred to in other breeds as lilac.

As for the “any color” reference, this is an acknowledgment of the fact that the black base color in black-and-tan breeds can vary when dilutions are involved. For example, the Doberman has four acceptable variations for this pattern: base colors of black, red, blue and Isabella (which is both red and blue factors existing together). Because Corsos can have a blue dilution (what in the breed is referred to as gray), this more general language prevents confusion about variations on the black base color.

Wandering Off the Path

So, basically, the current color disqualification in the AKC Cane Corso standard — again, “Any color with tan pattern markings as seen in black-and-tan breeds” — was written that way to cover all the variations that can exist in the black base color of a black-and-tan breed. Nothing more, nothing less.

Unfortunately, some Corso fanciers have interpreted the words “any color” in that sentence too broadly.

I’ve heard some argue that is means that any color with a pattern fits into the disqualification. While colors and patterns that aren’t mentioned in the standard need to be evaluated to determine if they are correct or not, that doesn’t make them an automatic disqualification in the AKC system, which is more exacting than the parallel FCI universe. (Such aberrant colors, even if not mentioned in the standard, can be excused for "lack of merit" or "color/pattern not in accordance with the standard," but logically they cannot be shoehorned into a disqualification that intends to address only black-and-tan and its corresponding dilutions.)

Another area where the “any color” wording has created confusion — and in some cases, even disqualifications — is with the so-called “carbon” dogs.

Carbon Dating

Carbonation is a word you'll come across in Corso circles. It is not mentioned in any standard.

“Carbone” in Italian means coal. And within the insular langauge of their breed community, Corso fanciers use the term to describe a sooty coat, appearing as if the dog has been sprinkled with coal dust.

The degree to which carbonation (carbonatura, in Italian) is accepted depends on which side of the Atlantic you sit. Generally speaking, American breeders tend to be more tolerant of the pattern, and dogs with varying degrees of carbonation routinely finish their AKC championships. Overseas, the pattern does not appear as frequently in the show ring — and when it does, is often limited to the head.

Another, more commonly used term for this coloration is “shaded sable,” a pattern in which the tips of the fawn hairs are black — or, in the case of a formentino, blue/gray.

The term carbonization comes from the italian word "carbone," which means coal. These sabled dogs have black shading in their coat that gives the impression of having been sprinkled with carbon dust.

“Typically, Cane Corsos have a more or less clear sable coat,” which is expressed by the genetic notation of Ay, explains Stefanie Henneboehl, who runs the popular Coats and Colors website and who was indispensable in helping me understand the presence of seal coloring in the Corso and other Molosser breeds.

This Ay allele is the clear fawn described in the Cane Corso standards around the world, she notes. “But some dogs express obvious black hair tipping in their adult coats” — or blue, in the case of formentini — which is produced by the Ays allele. “The shaded sable allele (Ays) is recessive to clear sable (Ay>Ays). So clear sable parents can throw a carbon puppy from time to time.”

Carbon or sabling in the coat can vary in intensity. Photo: Mercedes Messer.

Henneboehl adds that sometimes, sable dogs that carry the allele (at) that produces the black-and-tan pattern (Ay/at or Ays/at), or sable dogs carrying recessive black (Ay/a or Ays/a) can increase the black shading, but the difference can be subtle.

“And there seem to be unknown and untestable modifiers that also can meddle with the amount of shading,” she continues. “The shading often goes up the neck and forehead and forms a widow's peak, and it adds some amount of black hair tips along the back and on the tail.”

Charted Territory

All these expressions of fawn that we are discussing — clear fawn (which is what the majority of Corsos are); sabled fawn (otherwise known as carbon) and the dreaded black-and-tan — are found on the A locus. The coat color that is expressed depends on which allele, or genetic variant, a dog inherits.

Before we go any further in this discussion, here is a breakdown of these A-locus alleles (genotype) and how they express in a dog’s appearance (phenotype). This guide might be useful in trying to decipher the alphabet soup found in reports from DNA-testing companies such as Embark. 

Ay (clear sable): A dog that inherits one or two copies of this gene will have a clear fawn coat (assuming it is not “covered over” by alleles from another color locus, such as dominant black, or KB, which exists on the K locus). Ay is dominant over all other alleles on the A locus. In other words, if a Corso carries even one copy of the Ay allele, it is dominant over any of the other alleles listed below.

Ays (shaded sable): A dog that inherits two copies of this gene will have the kind of black-tipped coat described as “carbon” in the Corso breed.

At (black and tan): A dog with two copies of this gene will be black and tan, just like a Doberman or Rottweiler.

When Ay or Ays is combined with at, things can get a little complicated, which we’ll get to shortly.

Points Taken

So what does this all have to do with so-called “tan points” on fawn Corsos? (When I use the term "fawn," I intend it to mean all the shades of that color, from buff to red, all of which are normally present and acceptable in the breed.)

The black shading in carbon (that is, shaded sable) Corsos typically does not extend to the areas where black-and-tan dogs have their tan points, Henneboehl explains. The color in these tan-point areas “will mostly stay clear and look solid yellow,” though they might — like any fawn coat — still be partially covered by brindle, a black mask or white markings, depending on what other genetic color patterns the dog carries.

Carbon Corsos have clear tan areas in the same places where they occur in black-and-tan patterned dogs. While visually they may appear to be tan markings, genetically they are not. Photo Silviya Aneva.

To understand how this expresses in other breeds, look at sabled herding dogs in the Collie family. They have dark shading and clear tan legs, just like the carbon Corsos accompanying this article. They are longer coated, which may make the transition to clear tan on their legs seem less abrupt, and many are tricolor, so there is white in the mix as well. But if you look at the legs on a sable sheepdog breeds, like the Sheltie below, this is the exact same coloration seen on a carbon Corso.

This sable Shetland Sheepdog has the same clear tan legs that one sees on a carbon Corso.

Bottom line, Henneboehl says: “All yellow patterns come with these clear tan markings in the same areas where a black and tan would have its tan points: lower legs, muzzle, eye pips, chest patches, bum. Shaded sables have lots of clear yellow that covers these areas.”

What appear to be tan points on a carbon Corso are instead just areas of clear fawn (or, in the case of this dog, formentino) coat.

In other words, these carbon or shaded-sable dogs that appear to have tan points are not genetically tan pointed. Instead, their shaded sabling creates an unfortunate contrast between shaded and clear areas, creating the visual illusion of points.

So since fawn dogs naturally have these solid-fawn areas in their coat if they are sabled — and since we now know this pattern is not the direct result of the black-and-tan gene, but rather coloration that goes along with carbonation, which historically has been permitted in the breed to varying degrees — they should not be considered tan points, and so are not a cause for disqualification.

How Much Is Too Much?

While shaded sable dogs are not a disqualification, just how acceptable are they? Does it matter how extensive or deep the sabling is? Just how much is too much?

Those are subjective questions, and breeders and judges will have to arrive at their own opinions. But there is one wrinkle in the shaded-sable story, which Henneboehl explains this way: “The A locus patterns are notorious for producing intermediate phenotypes in heterozygous dogs due to some codominance between alleles.”

Simply put, if you have a dog that carries the black and tan gene (at) along with the dominant gene for clear fawn (Ay) or shaded sable (Ays), that combination can express as a muddled compromise between the two — a fawn dog that doesn’t have a black-and-tan pattern, but isn’t clear fawn either, instead having a heavily sabled, or black-flecked coat.

“Sable puppies that carry at (Ay/at) sometimes can have lots of added black shading and might look almost black-and-tan when young,” Henneboehl continues. “Many, but not all Ay/at are more shaded than Ay/Ay. However, in adult sable dogs, it would be unfair to assume they are at carriers because of their shading pattern.”

To make things even more complicated, the opposite can be true, too: Ay/at dogs do not always have added shading. “There are plenty of Ay/at dogs that have a very clear yellow coat,” Henneboehl says, like this rescue, whose genetic profile was posted to the Embark site.

Differences between black-and-tan puppies (above) and carbon puppies (below) can be seen in the whelping box. While the carbon puppies can be very dark, the tops of their heads are always fawn, and the black in their coats can sometimes clear dramatically by the time they are adults.

Henneboehl notes that even littermates who have the same Ay/at genotype can have “very, very different” amounts of black shading.

“While tan point carriers (Ay/at) are more likely to have a darker pattern, it is not predictable enough to sort out good dogs based on their sable shading,” she concludes. “There are too many unknowns in what causes different amounts of shading.”

So, while carbonation can result from Corsos who have two copies of the allele for shaded sable (Ays/Ays), it can also result from clear fawn dogs being black-and-tan carriers (Ay/at or Ays/at) — though that cannot be determined without genetic testing.

At the very least, Corso breeders who have dogs with carbonation should consider getting a genetic profile to see what the alleles their dog carries on its A locus. If the dog carries only Ay and/or Ays, no worries. But if the dog carries black and tan (at), know that it can produce black-and-tan if bred to a dog that also carries that recessive allele. And that, without question, is a disqualification in the breed.