Mismark Case Study: American Cocker Spaniel

American cocker spaniels are shown in three color classes: Black like the dog above (which may also have tan points), ASCOB ("any solid color other than black," meaning the shades of red, liver, and liver with tan points), and Parti-Color (which is any of the previously mentioned colors with piebale markings, with or without roaning). Image is from Wikimedia Commons under a Creative Commons license.

American cocker spaniels are a very common pet today in the United States, where they are simply referred to as the "cocker spaniel." It is in other countries where the "American" is added in to differentiate from the English cocker spaniel, which in England is simply called the "cocker spaniel". They are also popular in mixed breed form, with "cockapoos" and other "designer breeds" becoming more common all the time. Here are the mismarks seen in the cocker spaniel:

• Incorrect white
• Too little white (a parti is less than 10% white)
• Too much white (a parti is less than 10% color, or a solid has more than a chest spot)
• Ticking
• Particolors are supposed to have either clear white or be roan (uniform distribution of dark hairs)
• Incorrect tan points
• Tan is not clearly defined, is too minimal, or has black shot through (such as penciling, tar heel, or masking)
• Sable
• May be piebald
• May be liver pigmented instead of black
• Incorrect eye color
• Eyes are supposed to be dark brown, so blue is a no-no
• Blue eyes can be caused by both piebald and merle
• Merle (a controversial and unacceptable color)
• May be in combination with any previously mentioned color or pattern

This cocker has incorrect white and ticking

A blue eyed cocker with too much white

Cockers are usually bred using color classes due to the restrictions in the standard. If a parti is bred to a black or ASCOB, it is basically guaranteed that the puppies will end up having too little white to be shown as a parti and too much white to be shown as a solid. The exception would be if the parti had the extreme white piebald gene, but since too little color is also unacceptable, extreme white piebald is not as commonly seen as moderate piebald. As such, matings between the partis and the solid dogs are basically never done. Parti matings in and of themselves may be an issue, since it is possible that extreme white piebald may be hiding in a moderately marked dog. As such, it is quite possible for an extreme white piebald dog to be born from a parti to parti mating. Also, by it's nature, piebald can produce blue eyed dogs quite easily, which is not allowed according to the standard.

Interesting as well is the fact that ticking is not an acceptable marking pattern due to the current theorized inheritance of the ticking and roan genes. It is listed using the designation "A" meaning "alternate color," and as such is not acceptable according to the standard. According to current theory based on breeding information, a dog has to have at least one copy of the ticking gene to be roan. In addition, since a dog only needs one copy of the roan gene to be roan, it is very possible for ticked dogs to come from roan to roan breedings. This is possibly why roan American cockers are so unusual when compared to roan English cockers, as ticking is allowed in the breed according to the English cocker standard.

This cocker is a sable mismark

Also a fairly commonly seen mismark is sable, which is not allowed according to the standard as it is not a "solid" color. Sable may potentially come from several different matings. Part of this is because dominant black and recessive black are both seen in the breed. As such, breeding a black to a black has a rather high potential for producing sable dogs. This will happen when the dominant black dog only has one copy of the black gene and has at least one copy of the sable gene on the Agouti locus. As recessive black is recessive to sable, sables have a high chance of being produced in these situations. The same is true of breeding dominant black to black and tan, since tan point is also recessive to sable. So too with dominant black to dominant black if the dogs carry non-black (which allows the agouti locus to show through). Breeding buff, red, or silver (all of which are recessive red) to black also has a similar possibility of producing sables, both when dominant or recessive black is being bred to the buff. If the buff is sable under the recessive red, sables are quite possible, even to the point where an entire sable litter may be produced (if the black is not carrying buff). If dominant black is carrying non-black and either the buff of black is hiding sable, this is yet another situation that can produce sable dogs. The same is true if any of the black dogs mentioned above were liver.

This cocker is a merle mismark

I do completely understand why merle is not an acceptable color in the breed. Since buff (recessive red) and parti (piebald) are such common colors in the breed, mating merles to certain colors gives a very high chance of producing cryptic merles. Cryptic merles are often not identified as merle, and as such may be bred to another merle dog. A merle to merle breeding leads to a twenty-five percent chance of producing a double merle, and double merles have a very high chance of being blind and/or deaf. Merle was also not present in the early years of the breed, and as such must have been introduced through an out-cross fairly recently. Why anyone would purposefully introduce merle into a breed where it didn't already exist is beyond me, due to the potential health issues it can cause.

There are a lot of issues I see with the mismarks in the American cocker spaniel. As with every purebred, cockers are part of a closed registration and genetic diversity is of great concern. By restricting the breedings that are "acceptable" based on a color standard the breed is now bred in color classes. Color class breeding causes an already isolated gene pool to become isolated from itself, and as such it is at greater risk of serious inbreeding side affects than breeds where the color standard is less restrictive. Making it so that a dog is considered worthless based on its color is absurd. This is true of the American cocker spaniel and every other purebred out there.