Merle Colouring

The merle gene is responsible for creating mottled patches of color in a dog's coat and blue or odd-colored eyes. However, merle is an incompletely dominant gene, so not every merle dog will have blue eyes. And while merle dogs often have blue eyes, they can also have one brown and one blue eye.

Merle is inherited in a dominant fashion, meaning that only one copy of an M allele is necessary for a dog to display some variation of the merle coat color/pattern, which is marked by random dilution of eumelanin (black pigment) leaving patches of normal coat color within areas of diluted pigmentation.

The colour Merle is actually a heterozygote of an incompletely dominant gene.

A standard merle coat has two characteristics: A diluted base color and random patches of full pigmentation. In recent years, two spontaneous variations of merle have been recognized: dilute and harlequin. Dilute merles have a milder coat dilution with no patches.

Blue Merles are called “Blue Merles” because of the patches of the bluish color between the patches in their coat. The puppies in the pictures below show the difference in colours from a Phantom Blue Merle as seen in the puppy on the left, to a Blue Merle as seen in the puppy below.

Here is a Blue Merle Poodle born here at Gramayre

Here is a Red Merle Poodle Puppy born here, showing the golden green eyes also seen in Merle colouring.

Here is a Phantom Blue Merle Groodle born here at Gramayre

Here is a Red Merle Poodle Puppy born here, showing the blue eyes often seen in a Merle dog

Do Phantoms carry the Merle gene?

Yes Phantom merles still carry the merle gene. The Phantom Markings are Visible on the Merles or blue merles in a different shade of colour generally tan or can be white or other colours. As mentioned previously the ones to look out for and have DNA tested are the crypto Merles were the merle colour is not visible but hidden under the coat colour. Are single merle dogs healthy? YES. But again, if two such dogs (Merles) are mated, on the average one quarter of the puppies will be "double merles", which is the common term for dogs homozygous for merle, and a high percentage of these double merle puppies could have eye defects and/or be deaf. It is a common misconception that a dog with a merle coat must have hearing and seeing issues.

The only time the merle gene causes a concern for health is when a dog is homozygous for merle, meaning “double merle.” The only way to get a homozygeous merle dog is to breed two merles together. Reputable breeders will never breed two Merles together for this reason.