Is merle a defect?

Is merle a defect?

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.

What makes an Australian shepherd a merle?

The breed standards state that Australian Shepherds can come in some combination of two basic body colors (black and liver), one pattern (merle), and two trim colors (white and tan.) ... A blue merle is a black dog with the merle pattern; a red merle is a liver dog with the merle pattern.

Why can you not breed merle to merle?

It doesn't matter what color merle or what breed they are. If two merle dogs are bred together, each puppy in the litter has a 25% chance of being born a double merle. ... Double merles also have a very high chance of being deaf, blind, or both because they lack pigment where it would normally be.

Is it bad to breed two merle dogs together?

When two merle-patterned dogs are bred together, each puppy in the litter has a 25% chance of inheriting that gene from both parents. The resulting offspring is referred to as a double, or homozygous merle. ... Due to the decreased pigment on the skin, double merles are at a high risk for hearing and sight impairments.

Are single merle dogs unhealthy?

As long as a dog only has one copy of the merle gene, this is not bad or unhealthy at all. The problems only arise when a dog has two copies of the merle gene and is a double merle – then he will experience an array of health issues. ... Dogs appear to not be merle, but genetically they can be.

Are merle dogs prone to health issues?

The presence of the merle gene can be identified by DNA testing. ... Double-merle dogs carry a much higher risk of inheriting health problems, especially various eye problems and congenital deafness. Single-merle dogs are less likely to be affected by such problems and can remain perfectly healthy.

Do merle Aussies have more health problems?

While there are suggestions in scientific papers dating back several decades that double merles are more prone to a variety of health issues other than those mentioned above, most particularly heart and digestive issues, this appears to be inaccurate.

Are merle dogs unhealthy?

Yes – merle dogs can be just as healthy as dogs that have a solid color. They have the same life expectancy, they are just as strong and athletic and smart as their counterparts without the merle gene. In lines with responsible merle breedings, all offspring will be healthy and live a long life.

Do merle dogs have health problems?

Health Issues The merle gene is known to cause a number of health problems, mostly deafness and blindness, and also sun sensitivity and higher rates of skin cancer. These problems are unusual in heterozygous merles (Mm) but more common in homozygous merles (MM).

Why can't 2 merles breed?

Why you shouldn't breed two merle dogs together Don't do it. The merle pattern is produced when a dog has a single copy of the M< allele. All merle dogs have the genotype Mm — meaning they have one allele for merle and one allele for non-merle.

What does it mean when a dog has Merle?

• The pattern has been in dogs for many years, but wasn’t called merle until the early 2000s. The gene that causes merle in dogs is called PMEL17 or SILV. The merle color pattern is what scientists call “incompletely dominant.” It shows up when a dog gets just a single copy of the merle allele. It basically causes a dilution of color.

Why do some merle dogs have blue eyes?

• This Merle coats are caused by genes, which may also affect eye colors, coats, and more. The color is actually a recessive gene and it is not something that you can find in all the dogs that are going to be blue. You will have to know how many breeds that have this gene and where the other dogs are that is a good mix of the two different colors.

Can a double merle dog be at a dog show?

• In a ‘Mm’ dog, a tan color is not necessarily diluted. So, a blue merle dog may still have tan points. ‘MM’ dogs will be mostly white, with patches of color. Double merle dogs are not accepted at dog shows. Merles are generally split into the blue merle dog and the red merle dog based upon the type of melanin produced.

How many copies of the merle gene does a dog have?

• In each dog, there are two copies of a gene; one from each of his parents. We will call the Merle gene “m” and the non-merle gene “M”. If your dog gets two copies of m, the gene for Merle, it is considered homozygous (mm) or double merle. A dog with two merle genes will be mainly white in color.