Sunday, July 1, 2012

Mismark Case Study: Gordon Setter

A Gordon setter in the breed's only acceptable color.
The Gordon setter is one of a small number of setter breeds, which also includes the English setter, Irish setter, and Irish red and white setter. Though the Gordon setter now only comes in one acceptable color, the breed's history included a number of other colors that are now considered to be mismarks. Part of why these colors are in the breed is due to its relationship with the other setters. So, what are these mismarks?
  • Incorrect tan markings
    • Dogs with more or less than than required in the standard
  • Liver
    • Inherited on the Brown locus, a dog must be bb to be liver
  • Red
    • Inherited on the Extension locus, a dog must be ee to be recessive red
  • Too much white
    • Inherited on the Spotting locus, a dog with a variety of genotypes can have too much white

Too much white
Looking at these mismarks, they are all recessively inherited except in dogs that are genetically solid but have too much residual white. All of theses colors were well known when the breed was young. Much like the Irish setter, the predominant color in the early years of the breed is actually not what you think it would be when looking at modern dogs. Gordons were once mostly tricolor with some dogs being solid black and tan, liver, or red, but the white markings and other colors fell out of favor and led to the production of the breed you see today.

This dog appears to be liver
The current breed standard for the Gordon only allows for black and tan dogs with specific tan markings. Dogs that are anything other than black and tan are disqualified and anything more than a small bit of white on the chest is not allowed. A dog with more or less than the required tan would be penalized, despite the fact that ten markings can vary greatly on dogs that are all genetically atat tan pointed. So far, it is known that there are modifiers that control this amount of tan, but it isn't known where they are or how they are inherited.

Too much tan
This is a case where color standard is based on, basically, fashion. What once was popular was no longer liked by those who wrote the breed standard, and thus those other colors faded into obscurity. However, since the colors are basically all recessively inherited, they continue to pop up on occasion in litters that are born today. These past decisions are really problematic when looking at the breed's history and what this holds for the future.

Too little tan
Since Gordon setters were originally hunting dogs, the main thing that they should be bred for is working ability. This was at least true of setters past. However, modern Gordons have a lot more emphasis placed on type and show potential. It remains true that Gordons were developed as working dogs and color has no affect on working ability. It also has no affect on health or temperament, which are both important to people who wish to have a happy life living with a dog, particularly if the dog is meant to be a pet. If breeders wish to emphasize the Gordon setter's place as a working breed and its ability to do field work, why should they place any emphasis on color?

Another major concern in the Gordon setter and any other breed is a loss of genetic diversity due to selective breeding. Since Gordons of only one color were favored, a lot of diversity was lost rather early on in the breed. Continued shunning of off-color dogs only drops more potential sources of genetic diversity from the breed and risks loss of some very good, sound individuals based on a silly cosmetic preference.

Sources are the American Kennel Club, Gordon Setter Club of New South Wales, and Gambit Gordon Setters. Images are from Wikimedia Commons or Flickr.com under Creative Commons licenses: one, two, three, four, five.

1 comment:

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