Mismark Case Study: Great Dane

In continuing with my musings on mismarks, here is a case study of the great Dane. 

Great Danes is five of the six recognized coat colors: harlequin, black, brindle, blue, and fawn (mantle not depicted).

The great Dane is a bit curious to me when it comes to its color standards. There are only six recognized colors, but breeding within the gene pool caused by these colors can lead to not six color possibilities, but numerous more mismarks. Here is the full list of possible mismarks when only including the genes that make up the accepted colors:

This great Dane is a fawn mantle mismark

- Blue fawn
- Fawn mantle
- Brindle mantle
- Blue mantle
- Blue fawn mantle
- Blue brindle
- Blue brindle mantle
- Merle
- Merle mantle ("merlequin")
- Fawn merle
- Fawn merle mantle
- Brindle merle
- Brindle merle mantle
- Blue (dilute) merle
- Blue (dilute) merle mantle
- Blue (dilute) fawn merle mantle
- Blue (dilute) brindle merle mantle
- Blue (dilute) harlequin
- Fawnequin (fawn harlequin)
- Brindlequin (brindle harlequin)
- Double merle
- White (double merle harlequin)
- Harlequin (when the nose has too much pink)

And that's not including other mismarks seen in the breed, such as liver and piebald. To me, this is downright ridiculous. One of the major issues caused by there being so many color combinations is that is has lead to the breeding of color classes within the breed. The classes were created in an attempt to avoid possible mismarks, but the practice has only succeeded in isolating the different classes from one another. As such, it has narrowed the potential for genetic diversity within each color class. But, it also means that not only are breeders not supposed to breed, say, a fawn to a blue, but they could actually get kicked out of their parent club for doing so. To me, the standard is much too restrictive since isolating the different colors negatively affects the breed as a whole.

This great Dane is a white mismark

This great Dane is a merle mantle mismark

One of the biggest issues to me when it comes to the great Dane standard is the breeding of harlequins. Harlequin is caused by two genes: merle (M) and the harlequin modifier (H). Harlequin is lethal in the homozygous form, and as such, it never breeds true. So, mismarks aren't just possible, they're basically guaranteed. Also, it only affects the gray in a merle dog, so if the breeding produces black puppies without the dominant merle gene, even if they have the harlequin gene it will not show. Notice also that harlequin-harlequin matings are not only accepted in the color classes, but possibly even encouraged! I take great offense to this since, as I already mentioned, harlequins have a copy of the merle gene. Breeding two merles together leads to a 25% chance of producing a double merle. Double merles are very bad due to the fact that they have an extremely high chance of being deaf, blind, or both, among other things. It is not fair to the puppies to purposefully produce ones that are blind or deaf. And no, I do not approve of euthanizing them at birth because a smart breeder wouldn't have produced them in the first place.

This great Dane is a fawnequin mismark

This great Dane is a merle mismark

The sheer number of  mismarks possible from the presence of the harlequin dogs in the breed population in the first place is amazing. Sixteen different mismark combinations are possible thanks to the merle and harlequin genes, as opposed to only seven caused by the other genes alone.

As I've said before, I think the standard is far too restrictive. Is it really that bad if a dog is patched and fawn instead of patched and black? Or if a dog is brindle with blue stripes instead of brindle with black stripes? And why is it acceptable to breed two harlequins together and produce blind puppies, when it's not okay to breed a fawn to a blue and produce puppies with perfectly normal vision? It really is beyond me how anyone can think the great Dane breed standard makes any sense.