Friday, March 2, 2012

Mismark Case Study: Shiba Inu

I got a suggestion recently from MC over at The House of Two Bows to discuss the Shiba Inu mismarks, especially the cream coloration. So, here we go.

Two Shiba Inus is the breed's most commonly seen color: red. Image is from Wikimedia Commons under a Creative Commons license.

Red sesame
Black and tan
 The Shiba Inu is a breed originating in Japan and is a popular pet. Though the breed is most commonly seen in red, allowable colors also include black and tan and red sesame.

As with so many Asian breeds, Shibas have what is known as urajiro: pale points in a similar orientation to those seen in tan pointed dogs. Urajiro is not controlled by the same gene, though (which is why the breed can be black and tan with urajiro), and is either a simple recessive or a polygenic recessive. There is quite a bit of support for the polygenic theory because the intensity of the urajiro can vary so much. As with so many purebreds, Shibas have some mismarks:

  • Cream/white
    • Very pale recessive red
  • Pinto
    • Piebald white

This Shiba is a cream mismark
Cream is by far the most commonly seen mismark in the breed. It's caused by the same genes that cause white German shepherds. This color is a form of red that has just been very diluted. Characteristically, this means that the dog will usually not be white, but instead a shaded cream, often with red-tipped ears. Since it is a sort of recessive red, there will be no black hairs to be found on the dog. These genes also don't have any potential negative affects on the dog's health, unlike other forms of "white," such as albino, double merle, harlequin, and extreme white piebald. The only potential for health issues in dogs of this color would come from inbreeding which, since the color is recessive, is a common technique used by breeders who purposefully breed creams for profit. However, if a cream randomly pops up in a litter it will be no more likely to develop some sort of health issue than its siblings.

Pinto markings are also found in the breed, but seem to be far less common. It is far from unusual to see a Shiba Inu with a white paw or two and/or white chest, so there are several white spotting genes seen. Dogs with a bit of white, or even those that have basically none, can quite possibly carry the piebald gene that causes pinto. So, if you breed the right two dogs together, a pinto or two will pop up.

Another cream Shiba Inu
Though the Shiba Inu was once a dog used for hunting, now it is almost exclusively a companion animal. I have not found a single good argument as to why the colors continue to be excluded from the standard. Unlike some standards that exclude a color because of known common health issues that are linked to the genetics of the color itself, this is one of those cases where there doesn't seem to be any good reason to disallow the mismarks. Also, any attempts to breed them out really won't work because, if you remove all creams and pintos from the breeding population, you will still have dogs (including 2/3 of the siblings of the mismarks) who still carry the recessives. Any inbreeding that occurs will only make it more likely for the mismarks to show up. Even without close inbreeding, the occasional mismark will still pop up. In addition, by removing dogs from a closed population simply because they are the "wrong" color, precious genetic diversity is being removed for no good reason. In a closed population, genetic diversity is of serious concern because there is only so much to go around. Since the pedigree dog world is so against adding new genetic diversity by out-crossing to other breeds, what diversity there is needs to be maintained as much as possible or things do not bode well for a closed registry system.

28 comments:

  1. Delighted to see your take on this! Also very intrigued by your mention of the polygenic theory for urajiro. I had heard something like that before, but didn't quite know what to call it. I had read somewhere that this is one explanation as to why Shibas are called "black and tan" and not "tricolor" (like Basenjis) -- not sure if that's accurate or relevant, though.

    One more mismark that I was curious about, but you didn't mention -- the red-headed black & tan. This is also not a marking that you expect to see in "reputable" breeders' lines. Even if they're not born as noticeable red-headed B&T's, their red patch grows more distinctive with age so that they end up looking a bit like this dog as adults: http://nycshibarescue.org/2012/02/introducing-poe/

    You chose some great picture examples. Hopefully interested readers will click on all the links which you didn't include directly in the post (presumably because they're not all free for use). [Side note: I'm amused that I recognize at least two of dogs in your representative pictures because they are known Shiba bloggers. Heh.]

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    1. M. C., that dog looks saddle tan to me. Saddle tan is actually black and tan being modified, the modifier is unknown at this time. It's present in some populations of Salukis, too, and causes just as much, um, discussion ;)

      Tricolor simply means black and tan (or saddle tan) with white markings, typically Irish marking. Very common combination in dogs.

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    2. It pleases me that there's still a bit about coat coloration that remains unknown. As much as I wanted to hear the scientific breakdown from The Biologist here, I think I would feel somewhat cheated if everything about coat appearances was a matter of tweaking very specific genes.

      Red-headed black & tan shibas appear to be sporting a distinctive chonmage (http://en.wikipedia.org/wiki/Chonmage) which is somewhat appropriate for a Japanese breed and thus one way I can appreciate this look. But again, like the pintos, it often registers an immediate sense of unease in me because it's become so strongly associated with unethical breeding practices, at least in this breed.

      Back to the post... while breeding for the cream coloration is severely frowned upon, I don't think Shiba breeders are actively trying to "breed them out" for all the practical reasons you mention. They pop up with enough frequency in ethically-bred litters that they're regarded as a lucky variant when it happens. Kind of like getting the clear figure in a set of Japanese box toys, haha. =) Typically, as I understand it, the pairing is not repeated since creams are not "desirable" for show - but then wouldn't that just encourage a brand new pairing for the *next* breeding?

      I think the argument, as presented to me, is that the gene pool for Shibas is already large enough that you can continue to select for a rich, red coat without compromising genetic diversity. But others who are more acquainted with specific pedigrees and breeding practices are in a better position to comment on specifics than I am. (hint hint)

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    3. Jess is quite right, MC. The progression of which you speak in the saddled dogs is actually quite normal and is well known in every breed that regularly comes in saddled tan, as well as those that are only saddled on occasion. Here's some examples:

      Airedale terrier: puppy, adult
      Bloodhound: puppy & adult
      German shepherd: puppies, adult, time lapse
      Beagle: puppies & adult
      Basenji: puppy, adult (thought you'd like that one)

      From what I have found, it does seem like the modifiers that cause the difference between saddled tan and tan point have tan point as recessive to saddle. This has not been confirmed, though, so it's quite possible that I'm wrong. However, both would still be recessive to red (sable) and sesame (agouti). Since the saddle markings are not preferred in the show ring, selection has probably made show lines fixed or near-fixed for the modifiers that make a dog tan pointed, while the pet population probably isn't.

      I do like the comparison to the chonmage. Quite appropriate. :)

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  2. Very nice write up on it thanks. :)

    I plan check out your blog more.

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  3. Rubbish

    http://masakadoshiba.wordpress.com/2011/11/27/another-perspective-on-cream-and-white-in-nihon-ken/

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    1. What? I'm sorry, but what? Accepting dogs with the cream dilution would not make the red dogs any less red. Also, the effect mentioned in the Kishu breed can happen in any color, not just white, so it's silly to single out an example of the popular stud effect killing diversity (even if it's only cosmetic diversity in this case) and then act like it's the color's fault for swamping out the other colors in the breed. The same thing could just as easily happen for red, or black, or any other coat color.

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    2. Pipes is right, Lindsay. The reason why the color change happened in the Kishu is indeed due to the popular sire effect rather than the nature of the color itself. Also, what is discussed in your link doesn't make a very good argument as to why my statements should be considered "rubbish."

      As for concerns about breeding from cream causing a loss of color intensity, statistically, it wouldn't just be the creams who would end up being pale. Why is it that creams are always born from more intensely red parents and none of their siblings end up being, say, pale sesame? The genes that control red intensity will not affect the black hairs on a dog, and so if the paleness pertained to all reds you would end up with dogs from the same litters as creams regularly showing paleness. These dogs would look rather like most huskies, whose red is diluted down to white. There is something going on that only affects the creams. I already gave the example of the white German shepherd, and the same dichotomy of color dilution holds true in that breed.

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    3. Here's my theory about white/cream in the Japanese Native dog breeds:

      http://www.jindos.com/nihon/nihoncolortheory.html

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    4. I hope the photo-table helps demonstrate that there is a gene floating around in the Japanese breeds that does create paler red pigment. It's noticeable in the Japanese Akita and Kishu - the breeds that solid white is allowed. It's been seen in Shikoku with washed out red pigments (in the photo-table). Though not pictured, Kai that have black & white stripes rather than black & red stripes are probably showing this in effect. It's been seen in pet-store Shibas, and in person, I've seen two red show dogs that were known to produce creams and they were lighter in color than their show comrades.

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    5. ayk, your theory has been recently fallen down, as the C-gene has been found and there seems to be NO variation in dogs.
      White, like in Samoyeds with black nose is aa and ee. Cream is is most breeds ee. But ee can look like red.
      I research color in Chow Chows: Chow Colors

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    6. Xin-Feng, I don't doubt that people haven't found anything on the C-gene. They've been searching for quite a while. However, there does exist a gene, whose location is not yet pinned down, that does lightens up phaeomelanin. Otherwise there wouldn't be an explanation for the lost red coat color in Siberians, Malamutes, silver brindle Japanese Akitas, etc.

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  4. I have a different sort of question about shiba coat colors. The red sesame color is thought to be in the agouti series, when the dog is heterozygous for Ay-At. However, not all AyAt dogs appear "sesame" - some look like they are AyAy reds. In fact, they are still called "reds" even when they throw an AtAt puppy. (This makes me very cranky). My question is, do we know why some AyAt dogs have the lovely sesame coloring, while others appear just red?
    Also, I had a lovely sesame colored shiba who had red dam and a black and tan sire. His fur was quite banded - grey at the base, red in the center, a slim band of white, and then a black tip. This banding has been described in the malamute/husky type dogs as the Aw allelle at the Agouti locus. Do you think this might be operating in shibas? Or are there other ways to get a banded hair shaft?

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  5. Back to creams - whatever the allele that causes it, it is presently at a relatively low frequency in the responsibly bred population of shibas worldwide. (Which, currently, are easily bred across borders.) The Japanese and Americans discourage the color, so pups that have it are not bred. Their siblings (potential carriers) are not discriminated against, however, so this practice should keep the gene frequencies for cream color more or less stable. It might decline slighly over time, but not due to any sort of intense selection against it that would endanger other traits in the breed.
    If creams were accepted, then they would be retained and bred. This would increase the frequency of, say, ch, so creams would be more likely to pop up in litters. The problem is, the colors red and black&tan are preferred. Every breeder dreams of that perfectly marked marked black and tan or brilliant orange dog. If ch were present in a higher frequency, I feel that breeders might do more inbreeding to avoid it. The ch allele in high frequency would play havoc with the quest for the above two colors.
    And, lastly, urajiro is a hallmark of shiba color; it reminds one of the countershading on wild animals - deer, coyotes, lions - and adds a touch of wild mistique to the breed. That is lost in creams. I have heard that reason given often among good breeders. They also work hard to balance urajiro - not too much, not too little. Again, a high frequency of ch would complicate that goal.
    I have read your blog for many months and enjoy it greatly! Couldn't resist on the shiba comments though, as they are my breed. Thanks for listening!

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  6. I apologize for the curt reply. For the last several days blogger has not accepted my permissions to post and deleted my responses. In the meantime, Pam and Ayk filled in what I had intended to say.

    I did want to remark that popular sire effect is a reality in Shibas and a lot of bad genes have seated themselves in the breeding population. I know the instant the first cream champion happens in the US if ever the standard is changed to reflect the UK standard (not likely anytime soon), there are those who will over use the dog as they have over studded correctly marked dogs, and the occurrance of cream carriers will dramatically increase, but without a good way to track which dogs carry it since ch and agouti are seperate. That's why I mentioned Kishu. They once had the variety and now the color in the yushoku is really poor quality, in a breed that has a small population and questionable health.

    Mode of inheritance of cream involves many factors. It's true that cream can come from clear vibrant reds, but my concern is with dilution and long term effects of breeding creams, carriers and light colored dogs together over many genreations. We know that breeding recessives over time can cause issues, and with dobermans for instance, the really dilute colors are associated with health issues.

    I too notice fading and dilution of colors over time when the very light colors are bred. Clear red to clear red over time will result in faded color and washed out faces. The same happens in the other related breeds. Red brindle to red brindle or cream washes out the color in Kai, and the same is true in Shikoku reds and Hokkaido brindles, where brindle is so rare there is no choice but to breed to the multitude of cream dogs. I don't want that to happen to Shibas.

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  7. Hi, this is off subject but I can't find any info - can you help please? What is the likelihood of getting black and tan pups from a red (with very minor black tips on hairs around neck) and a black sesame? Would there be any chance of this?
    Thank you in advance for any info you can give me.

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    1. Since tan point (black and tan) is recessive to both sable (red) and agouti (sesame), as long as both parents carry the gene they can easily produce black and tan puppies. Generally, in such a situation you would expect approximately 25% of the litter to be black and tan. However, such statistics are approximations and, though unlikely, you could get a litter that is mostly or completely black and tan.

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    2. Thank you Stephanie - that's great news! I know of only 1 black and tan dog in New Zealand and SO hope I can breed one for myself. Fingers crossed! Thanks again! Have an awesome week! G ;o)

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  8. As the owner of a cream shiba that I hope to breed, I found this discussion fascinating and somewhat validating. Having visited the shiba forum on occasion - and recognizing some of those names here - this kind of thinking is refreshing in the face of the somewhat strident orthodoxy found there. Seeing the mess that "responsible breeders" have made for many types of purebred dogs, I'm more convinced than ever that inquiry and skepticism are an important counterpoint to that tendency.

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  9. I am also a owner of a cream shiba and have had many request to breed her. I want to breed her more due to her temperament. I was approach by another shiba owner with red/sesame and black markings. Reading everyone's replies I would like to get your opinion because I too want to be a responsible breeder more for the temperament than the color. Look forward to you comments.

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  10. I know this is and old blog but I have been looking for info on urajiro! I do not have a Shiba but French Bulldogs and I noticed that in some dogs especially reds and more in Euro lines that they had these white or cream points but could find no info about this marking and no one even mentions it. Like no one notices it! Well I happen to have a male with the cream points and just a small amount of a black mask but he has a grandmother which looks solid cream but if you look close you can see the white points on her too and now one of his pups that was born with a black mask not as deep as her brothers is losing it and she has the tan points. I was doing some research and found a few other Frenchies born with the mask but loosing it completely and having what looks just like urajiro! Here is what I wonder though. Every site says urajiro does not affect black hair only red, well then why does it cause them to lose their black mask ?

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    1. I think I have a french with this color but he is mask less.

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  11. http://i63.tinypic.com/14xeb05.jpg


    Every time people see my Shiba Inu they think she is a mix because of her coloring and markings. Just wondering peoples thoughts on what her coloring is and if you think she is a mix or not?

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    1. Here's a more recent pic of her -

      https://www.instagram.com/p/9bUix3qI5f/?taken-by=kira_rey_the_shiba

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    2. Here's a more recent pic of her -

      https://www.instagram.com/p/9bUix3qI5f/?taken-by=kira_rey_the_shiba

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  12. I have a beautiful "white" male akita and during different times of the year his coat will turn a peachy looking color with dark peach tips and a barely visible spot on his back....LOVED the info here! cool! wish I could add his pic for you to see.

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  13. I have a 12 week old pinto Shiba that loves to bite. I have tried several methods of stopping this and to no avail he continues. He has been to our vet several times that said he is smart, curios and active. I am worried because I have read an article or two about pinto Shibas being prone to biting. What could be perceived as normal puppy behavior I start to think it's OCD related. I have also noticed that there seems to be a high number of pinto shibas sold in the general area of where I purchased him from. Do you think I should have him tested by a neurologist?

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