Merle
The merle gene is like blue (dilution on black) a gene that leashes out the basic color. This I call Dilution on English but don’t mix it up, because this is 2 different genes. This means in practical, that this merle gene will turn the color around, so that a black colored coat will be grey with black spots on. On the Bergamasco the merle color will be show right after they are born, many merle colored dog have blue eyes, but this is not allow on the Bergamasco. Although merle is a generally treated as a dominant gene, it is in fact an incomplete dominant or a gene with intermediate expression. A dog with mm is a normal colored dog. A dog with Mm or mM is a merle dog. A dog with MM is an double merle dog (both of the parents will in this case be merle colored.) and this copulation will provide several of problems for the dog.
25 % of litters there have 2 merle parents, will first at all have an very light colored coat almost white, some will also have other defects as deaf less, eye defect and / or sightless, not all the puppies from this kind of breeding will be deaf, it depends how the ear are pigmented on in inside. Missing this pigmentations will the nerve cells that are responds for the hearing, be damages so it can’t produce nerve impulses. Almost all double merle puppies will have big or small deviations in the eyes, because of uncorrected development of the tissue. The most normal is that the eyes are a little small than normal, or sometimes missing totally. But also an uncorrected form on the pupils is a known defect. Because of all this, is not recommended to do breeding between 2 merle colored dogs. In some country it is illegal to do this kind of breeding, and the puppies can’t be registered.
This is an example on a double merle puppy with fault and missing’s.
This Bergamasco puppy has lost of disqualifications fault, because of breeding between 2 merle colored dogs. This dog is to white, and missing pigmentations on the nose and it have blue eyes.