Merle Dogs, How to get the Color
In recent years, «merlé» or blackbird coats, with a bluish-gray tone, have become very fashionable in medium-sized dog breeds such as the Border Collie or the Dachshund.
However, behind these beautiful colors hide a series of genetic health problems, some of them serious and that must be taken into account before acquiring and breeding with one of these specimens.
What Happens when a Merle is Crossed with a Merle?
In dogs, the so-called «merle gene» causes the coloration of their hair to be diluted or lightened unevenly, so that a black and white dog will have gray areas or spots, while a white and brown dog will have be white and cream.
These are the so-called «blue merle» and «red merle» layers that have been so fashionable for a few years. Dogs with this coat are more in demand and have a higher price than those with a solid color and, furthermore, the grayer or creamer the animal, the more expensive its market price will be.
the double merle may have eye and/or hearing abnormalities. That is why it is recommended not to cross 2 Merles, since the probability of generating Double Merles is then 25% compared to the null possibility of producing them when crossing with an animal with solid fur.
How to know if your Dog is a Merle?
Since the genes that code for color come in pairs, in the cross between a solid colored dog (two normal genes) and a “merle” coat dog (one normal gene and merle) about half of the puppies will come out solid. and the other half “merle”.
For some breeders this is not enough and with the aim of obtaining more profitability they have wanted to go a step further by crossing specimens with this gene. Some double merle puppies (two merle genes) are obtained from this cross.
Merle is very fashionable right now. Some simply find the fur on their feet pretty, others fall in love with their blue eyes or use their dog as an expression of status and prestige.
The fact that Merle has a genetic defect quickly fades into the background. Dodgy breeders see an opportunity to make big bucks and knowingly violate animal welfare laws and ethical standards.
How to know if its Double Merle?
The «double merle» animals are characterized by having a practically white color (not to be confused with albinism) but, behind their beauty, many diseases hide. The first problem is usually congenital deafness. This is because for the inner ear cells to function properly they must contain a pigment that «double merle» dogs do not have.
Health Problems and Merle Dogs
These specimens also present eye and vision problems, from mild pathologies such as small defects in the pupil to more serious ones such as significant alterations of the pupil that prevents them from adapting to light and malformations of the iris, to lens dislocations (microphthalmia). that is, smaller and less developed eyeballs (even non-existent), which cause partial or total blindness from birth or over the months and years.
In addition, due to the light color of their skin, these dogs are more sensitive to solar radiation, so if we do not take extreme precautions, they can suffer more burns and a higher rate of dermatological pathologies.
Due to these problems it is recommended to avoid breeding this type of specimen. Genetic tests are currently available to detect the presence of this gene in carrier animals (with solid color), something highly recommended before crossing specimens of breeds where this mutation appears frequently, such as all collies, the Dachshund, the Chihuahua, the Pomeranian, Australian Shepherd, Great Dane, etc.