Mismark Case Study: Dalmatian

Dalmatians in their two accepted color varieties: black spotted and liver spotted. The central dog is liver, while the other two are black. Image is copyright free from Wikimedia Commons.

This Dalmatian? has a large patch and indistinct spots

Dalmatians have a very distinctive appearance, and their color standard has a quite narrow range of what is considered "acceptable." The spotted coat is caused by the combination of two genes: extreme white piebald and what is believed to be a modified form of the ticking gene. This is why the puppies are born white and the color appears later. This is also why patches will appear (where a puppy is born with some color), all caused by the extreme white piebald gene not removing all of the color from the body. Both acceptable colors are caused by the dominant black gene, thought the liver dogs are also expressing the recessive liver dilution. Due to the dominant nature of the black, there is a great amount of potential for mismarks. In fact, quite a remarkable number of mismarks are known in the breed, almost all of which are caused by recessive genes:

• Lemon 
• Moderately pale to very pale recessive red

  

  This Dalmatian is a lemon mismark

• Orange
• More red-ish recessive red
• Blue
• Diluted black
• Fawn
• I don't know if it's been documented
• With blue possible, fawn (blue + liver) is possible
• Tricolor
• Tan spots in the same regions seen in tan pointed dogs
• May be black or liver (potentially also blue or fawn)
• Brindle
•  Stripes on red, of course 
• May be black or liver (potentially blue or fawn)
• Trindle
• Where stripes are seen in the points 
• May be black or liver (potentially blue or fawn)
• Sable
• Has the potential for black, liver, blue, or fawn pigment
• Indistinct spots
• Spots with edges that aren't crisp
• Improper eye-rim pigmentation
• Pink either in part or in full
• Too few spots
• Very few or no spots 
• Too many spots
• When the spotting is too heaving 
• Patches
• Present from birth

This Dalmatian has too many spots

Since the cause of nearly all of these mismarks are recessive genes it is nearly impossible to remove the color from the gene pool. As such, they continue to appear. Some of the variations may even be considered rather common, while others are more unusual. However, it is quite remarkable how many variations are frowned upon, especially when it comes to such things as patches, the density of the spots, the distinctness of spots, and eye-rim pigmentation. By the nature of the two genes that go into making a dalmatian a dalmation (extreme white and ticking), all of these variations are not just very possible, but almost expected. Even all white dogs, since ticking/spotting is dominant, a dog without the spots is quite possible. Eliminating dogs who express these unacceptable variations from the population by not breeding from them is basically a pointless endeavor. The variations are common because some of what goes into the density and placement of the spotting is random chance. This is true of both the extreme white and the modified ticking. As such, eliminating the dogs from the breeding population will not prevent the undesirable phenotype from occurring. Removing these dogs only serves to decrease the genetic diversity in the breed.

This Dalmatian has incomplete eye pigment

The require for completely pigmented eye-rims is rather ridiculous, in my opinion, as extreme white piebald, by its nature, will cause a loss of pigment all over the body. As such, it is very common for the gene to cause a loss of pigment from the skin as well as the coat. In truth, part of what may cause so many Dalmatians to have black eye-rims is the presence of those spots. They grow from dark spots on the skin, and as such dogs with black spots around there eyes are more likely to have fully black eye-rims. However, chance may very well lead to a dog with virtually do face spots and completely pink eye-rims. It seems silly that the standard allows blue eyes but not pink eye-rims.

As I have mentioned time and time again in these case studies, frowning upon a dog just based on its color is absurd. Especially if the differences are minor, and even more so if the variation is a common one and occurs due to the nature of the genes that go into the making the breed's acceptable standard colors. Even worse, dropping these dogs needlessly narrows genetic diversity in breeds that already have serious inbreeding problems thanks to closed registries and heavy selective breeding.