View Full Version : Dog coat and eye color genetics

10-02-2019, 09:36 AM
It seems that there are several genes involved in dog coat color. Dog breeders probably know these well, since certain breeds like Rottweilers and Dobermans have characteristic color patterns (such as yellow spots in their forehead and dark lines in their paws).


Contrary to what we observe in humans, in dogs eye color often shows no relationship with coat color. I've seen black or brown dogs with light brown or yellowish eyes, and yellowish dogs with dark brown eyes, as in these Labs:


I've also seen dogs with the same coat color but different eye color.

Dogs are also quite variable when it comes to ear shape. Some have pointed ears like those of wolves, others have droopy ones, and others fall somewhere in between. I've even seen dogs with one pointed and one droopy ear.

10-02-2019, 07:15 PM
The classic black and tan seen in Dobermans is also in Cocker Spaniels. The black and tan allele is fixed at the agouti locus in spaniels and only shows up when there is a recessive allele at the K locus (so not dominant black i.e. the agouti locus can be expressed) and the dominant allele (so has the ability to make black) at the E locus. My other Cocker spaniel is golden so is recessive ee at the Eumelanin locus and unable to make black pigment. I agree with you, dog genetics is very interesting.

10-03-2019, 11:25 AM
It seems that some dog breeds are more homogeneous when it comes to coat color than others. For example, in the case of Labs we have only 3-4 colors that tend to be uniform. I find it amusing when one can identify the different breeds in a mixed-breed dog by just looking at his/her coat. For example, this one probably has Pittbull and Rottweiler relatives: 33614

10-06-2019, 12:50 AM
Coco is a liver and white Springer. She had tricolored siblings, though. 33702

10-06-2019, 10:56 AM
More on Labrador's coat color (it seems that there are just two loci involved in this breed).


In the case of Cavalier Spaniels, there are at least three:


German sheperd:


The Agouti locus:


Other coat colors (brindle, tricolor, wolf grey):