Is the color Merle a sign of Mutation in all dogs ?

Merle is a modifying gene that causes a disruption in pigment cells found throughout the body. It is incompletely dominant so that a single Merle gene with a single normal (unmodified) gene will produce the Merle partial dilution color while a double-Merle genotype almost always results in a dog that is very pale or has few colored patches and suffers from health problems (pigment cells are important in both sight and hearing, for example, as well as for protecting the skin and hair from UV radiation).

Merle can be combined with almost any base color to produce different colors like a brindle merle, which looks quite different from both a brindle and from the more traditionally thought of "blue merle" dog: http://www.cardicommentary.de/images/brindle_merle... in single doses, Merle is not considered to cause health problems.

Anytime a Merle is bred to a Merle, 25% (not 50%) of the puppies will have the "double merle" genes and the associated health problems of deafness, blindness, etc. These puppies can generally be identified at birth as they will almost always have much more white in their coats and very, very diluted or washed-out markings (if they have any). Ethical breeders carefully screen their dogs to catch "cryptic merles" where the Merle gene is present but very hard to see in the phenotype: http://www.cardicommentary.de/images/Cryptic_merle... and will never, ever, ever intentionally breed together two Merle dogs, if a mis-mating occurs, the double-merle pups are often euthanized at birth. This applies across all breeds where Merle is common or is sometimes found (note: in Daschunds this color is called Dapple but is the same color).

Dachshunds even have merle. at the same time as the merle trend is standard, piebald and double dapples are no longer. You get those people who're breeding merle/piebald and of direction, there are constantly the idiots that attempt merle/merle. The DCA does enable the merle, yet would not enable piebald or double dapples. i hit upon it particularly exciting that every time I meet a dachshund that's a merle or piebald or mix of the to varieties, they many times come from a petstore. although I easily have seen a million merle longhair interior the practice ring...it grow to be basically a million and to this element, I easily have not seen yet another. although I did see an somewhat severe-high quality shifting piebald, which grow to be no longer picked because of the fact that is a piebald and admittedly, grow to be shocked to even see it interior the ring.