Got the Boerboel blues -- or is my dog a Blue Boerboel?

Just a little more information re: the blue gene in dogs; presented in a format that might make it easier to understand.

D-Series - for dilution
The "D-series" has only two genes (or alleles) to have to learn and understand: "D" and "d" - making it nice and simple. Even better yet, there's a simple order of dominance in play: dominant "D" (requiring only one "D" gene to fully express Eumelanin color), and recessive "d" (requiring two "d" genes or "dd" to produce the dilution action, and exhibit a visibly diluted Eumelanin color).

What Can Be Diluted?

Dilution through the "D-series" primarily affects Eumelanin, or the "Black" or "Chocolate" colors of the coat. While there may be some minor affect to Phaeomelanin (tan or red) with the dilution action of "dd," the visible effect is minimal - if at all.

Both Black ("B_") and Chocolate ("bb") Eumelanin can be diluted. Neither of these colors is a dilute, in and of itself.

When the double recessive of "dd" is present, the Eumelanin color is diluted. Black Eumelanin is diluted to "Blue" ("B_/dd").

Dominant D


When the dominant "D" gene is present (and remember, as a complete dominant, it only requires a single "D" gene in the pair to visibly exhibit its dominant effect), the Eumelanin color is fully expressed, with no dilution. This means a dog who is "DD" may be visibly identical to a dog who is "Dd," even though they are genetically different.

It is readily apparent on a brown/black brindle that it is "dd"; they are a steely/slatey blue in color. On red dogs it is sometimes apparent; their mask/ears are steely/slatey blue in color.

It is when the dog only carries one copy and is Dd and is bred to another Dd that there is the possibility of surprise blue pups in the litter.

From chasing bloodlines backwards in known red/blue mask Boerboels and trying to spot blue in older fuzzy photos; I would suggest if you were interested; keep an eye on the lack of pigment on a dog's ears to signify some dilution (maybe not blue but some other Boerboel specific dilution factor) and check eye color. The lighter the eye colour; the more likely dilution in either dd or Dd would appear.