According to the Japanese standard for the Akita used by the FCI, urajiro is "whitish coat on the sides of the muzzle, on the cheeks, on the underside of the jaw and the neck, on the chest, stomach, the underside of the tail, and on the inside of the legs." If you think about this definition, you can see that these are the same places that rust or tan is found on the Doberman. These places are commonly referred to as the "points."
While urajiro are referred to as "whitish," in fact, they can vary considerably in color and shading. I have a gray Akita here who is very like a Norwegian Elkhound in color (Sherob's Miyako of Karasu Oka on my web page). She has urajiro, but on her they are a very light silvery-gray. I have seen silver brindles with this type of urajiro also.
Probably the same genes determine the location of this marking pattern in all dogs and the color they assume is controlled by genes in another location or by an interaction of genes in several. Regardless, urajiro appears to be a very recessive marking pattern that can be found in wolves and members of the Spitz-family. Almost all of the native Japanese dogs demonstrate this marking pattern as do Chow Chows, Shar-Pei (where it is disqualified), and Pomeranians. I am sure that urajiro can be found in many others of this family recognized outside the AKC.
Akitas are a good case in point because they have the genes for all sorts of colors and markings. I've had a lot of different patterns in my own Akitas. Based on my breeding experiences, I'd guess that the most dominant facial marking is the black mask. Certainly this is what most people think of when they visualize an Akita. Masks are also found in many other breeds, including Mastiffs, Bullmastiffs, German Shepherd Dogs, Belgian Tervuren and Malinois, Great Danes, etc. Everyone has seen dogs marked like this.
Another marking pattern that is recessive to the black mask but found quite commonly in dogs is the self-masked dog. These dogs have a solid-colored head with no masking. Pembrokes can be self-masked. So can German Shepherd Dogs as well as many of the sporting dogs and hounds.
To make matters more confusing, dogs can have white markings independent of the base coat color and points. These can overlay whatever color would be present were the white not. Understanding that the white hides whatever is underneath is important. Just because you cannot see the color that would be there doesn't mean it doesn't exist genetically.
Before going any further, I'd like to add a disclaimer. I am not a breeder of Pembrokes, although I know a great many people who are, and I have not seen tons of puppies. If I am mistaken as to what happens in your breed, please understand that I am approaching this primarily from the standpoint of the breed in which I am active and have seen lots of puppies and adults.
Pembrokes primarily are self-masked or have urajiro along with white markings on the head and body. In the Pembrokes I have observed with urajiro, the white markings on the legs cover where urajiro would appear on an Akita or a Shiba. However, the shadings in the breaching are quite typical, as are the lighter, softer shadings on the cheek and above the eyes.
While Akitas in the US can have all sorts of markings and colors, the Japanese have narrowed their acceptance of color in Akitas to solid whites, brindles, sesames (like the sable Pembroke), and reds. Obviously, whites are white all over, but the other three colors should have either self-masks or urajiro. In fact, sesames are almost nonexistent and all reds shown have urajiro of some sort. The Japanese are quite concerned with the aesthetics of their dogs, so color and markings are of vital importance in breeding and judging them.
Although white markings on the urajiro are frowned upon, the Japanese have been breeding and rewarding a number of dogs with urajiro masks that approach being white. In fact, I've seen a few that were so bright that they are distinguishable from white only when viewed next to it.
The urajiro I am more used to and which was much in evidence in Japanese Akitas several years back was a much softer coloring and could vary from an almost beige to a creamy white. This shading blended in very well with the red coat colors. However, Akita puppies born with this color urajiro often have a black mask when they are born. This mask doesn't cover as much of the face as the mask on a puppy that will remain black-masked nor is the color as deep or as black. It has more of a sooty quality to it.
As the puppy grows, the urajiro becomes more evident and the mask begins to get smaller and lighter. An adolescent dog may look a lot like carbon paper has been rubbed on its muzzle. Eventually, the mask is gone altogether. In my own dogs, which are thoroughly American breedings for generations back, the mask may not disappear until the dog is close to two. I suspect in Japan, this occurs at a much earlier age.
Unfortunately, for them, in some dogs the mask never quite goes away, although it rarely comes past the mid-point of the muzzle and is rarely very black. I've seen Shibas like this too. In Shibas and in Japanese Akitas, the residual mask is unacceptable. My understanding is that the more closely the urajiro approaches a truly white color, the less likely the residual mask is to happen and that many puppies are born with no mask at all.
However, every dance has its price, and in this case, the dilution of the mask color to an ivory white is often accompanied by a dilution of the red coat color to varying shades of reddish-blonde. Also, the markings of the urajiro tend to spread farther over the dog, which is what sparked the discussion between Stephanie and myself.
The breaching in these dogs is lighter and brighter and the light color may spread farther over the leg. Light begins to appear on the underbelly, and even the margins of the ears may show urajiro. In the Japanese Akitas I have seen like this, the hair on the ears has a rather mottled appearance since the markings there are not sharply or clearly defined. Stephanie relayed to me that many Pembrokes have this same marking on the ear and that people who are not familiar with urajiro feel it is the appearance of white markings on the ear.
I've looked at white markings pretty extensively in a lot of breeds. Because someone can always find an exception, I'm not going to say categorically that white doesn't appear on just the ear rims. However, I'd be willing to bet that if it does appear there, it is accompanied by an incursion of white that begins at the base of the ear and extends upward. With urajiro, the lighter color extends up the forehead and cheeks, so extension over the rims of the ears and down from the tips is quite possible.
The Japanese prefer that their red dogs be a very dark red rather than strawberry blonde. I have a dog here of that color, and she is really a very dark pumpkin orange mixed with red. Often, these puppies are born black. Again, this black isn't really the same black as a puppy that will remain black. Instead, it has a reddish cast to it. This becomes the undercoat when the red outer coat grows in. Some dogs with this kind of red are actually like a reverse sable, with black at the base of the hair and a black undercoat as well.
I don't know if Pembrokes puppies are ever like this. Generally speaking, the darker reds with urajiro have less extension of the cream markings and those they have are more of a brighter, lighter shade of the base coat color rather than an ivory.
Once you have the genes for the color dilution in your line, however, breeding to other reds, especially those that carry the same genes will cause a brightening and lightening of the red color in successive generations. The first generations out of dark red will be a very pretty red-gold, but in subsequent generations this tends increasingly towards a blonde color. This dilution can probably be corrected by breeding to tricolors or very dark sables.
If you have access to the Internet and would like to look at examples of what I have described, you can go to my website at http://www.hypecon.com/doginfo/swindex.html. From there, go to the dog section and Sherob's Akitas. Look at Ch. Sherob's Muffin of Karasu Oka who has a link from this page. She is an American dog with cream urajiro.
At the bottom of the kennel page is a link to Que Paso. His puppy picture shows the black mask and black coat color with red coming in. Also, notice that what appears to be white leg markings actually darken to urajiro in the adult dog. His mask will probably be gone in a few more months. Also, if you look at the hair in his tail, you can see the black undercoat. This is really only visible when the dogs are coming in or going out of coat.
Any questions or comments can be addressed to me at mailto:rwallis@fc.net or 726 E Creekside, Houston, Tx 77024.