What is a lethal merle?
A single merle gene can produce results as harmless as fur or eye color and as difficult as loss of eyesight or hearing. However, mating two dogs with the merle gene can produce offspring with a homozygous double merle gene, sometimes known as “lethal white” or “double-blue.”
Is merle a lethal gene?
There is nothing lethal about the merle gene, it can just be problematic. Lethal white is a completely separate gene which does not occur in dogs. It occurs in horses, and is recessive, unlike the dominant merle in dogs.
Can double merles be healthy?
The quick answer is that a well-bred merle dog with one copy of the merle gene will be as healthy as a solid-colored dog. If a dog is a so-called “double merle” however, he is likely to suffer from vision, hearing and skin problems.
Can lethal white foals live?
What is the prognosis for overo lethal white foal syndrome? Affected foals do not survive. The prognosis for carriers is excellent as there are no known health problems (aside from deafness) associated with carrier status for this disease.
Do white Australian Shepherds go blind?
They can even have “split” eyes, in which half the eye is one color and the other half is a different color! However, you should avoid purchasing a completely white Australian Shepherd puppy or adult rescue dog. The white coloration is genetically linked to blindness and deafness in the breed.
How do you get a merle dog?
Merle is actually a heterozygote of an incompletely dominant gene. If two such dogs 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.
How do I know if my dog has the merle gene?
The merle gene modifies the dark pigment in the eyes, occasionally changing dark eyes to blue, or only part of the eye to blue. Since Merle causes random modifications, both dark-eyed, blue-eyed, and odd-colored eyes are possible. Color on paw pads and nose may be mottled pink and black.
Are double merles always deaf?
Double Merle dogs are highly likely to suffer from hearing and vision impairments and in some cases complete blindness and deafness. Deafness and hearing impairment happens due to lack of hair pigment produced in the inner ear. Double Merles can also be blind or have vision problems due to congenital eye defects.
How do I know if my dog is double merle?
Dogs with the double merle gene may be/have:
- All white in color, or have patches of merle/mottled coloring on the top half of their body – their head, back, and base of the tail.
- Light-colored paw pads.
- Have light blue, green or brown eyes, perhaps even eyes that are different colors.
Do all merles have blue eyes?
Eyes and Noses The eyes may be all or partly blue, and the nose may be all or partly pink. Above are examples of “butterfly” noses on merles, which are partly pink. Not all merles have blue eyes or pink noses though, and merles with heavy dark patching are more likely to have normal eye and nose pigment.
How do you test for lethal white?
Overo lethal white foal syndrome can be diagnosed based on the characteristic white coat color paired with the available genetic test. It is important to note that some foals are born with very light-colored pigment (such as cremellos) and other white spotting patterns, but are not affected.