MERLE - The Myths and the Misinformation!
By: Carol Keen
I just got so frustrated with a bunch of incorrect thinking about the merle gene in dogs, specifically in Pomeranians, that I am now going to see if I can't help clear up some persistent and silly confusion. Let's start with a question!
What breeds have the merle gene?
It is lots of dog breeds! Pomeranians, Great Danes, Dachshunds, Chihuahuas, Collies, Shelties, Australia Shepards, Welsh Corgis, Pyrenean Shepherd, Bergamosco Sheepdog, Old English Sheepdog, Catahoula Leopard Dog, and Cocker Spaniels. I know I have missed a few breeds that have merle genes. However, this will show you that this gene is in many breeds. It is not a "brand new" gene, nor a gene that no one knows about. It can be a bit tricky for those who don't understand genetics, but I am hoping to help a bit here. Most people are not breeding or raising dogs, but as an dog owner you still might wish to understand about this gene.
What is a merle gene?
The merle gene is an incomplete (defective) dominate gene. That doesn't mean it makes the dog Alpha, nor that it it tells you to go wash your dishes when they are in the sink! What it does mean is that this gene, when a dog has it will show up. Now, the incomplete dominate part is where folks get lost. For now just think of it as dominate, and keep reading on!
WHAT does the merle gene do exactly?
Merle is a random dilution gene. If you ever played pick up sticks, you know they never fall the same way twice. For folks who never played pick-up-sticks, think of bleach. Take a tooth brush and dip it bleach. Now splatter a black t-shirt with the bleach. You will NEVER get the exact same design twice. You might get similar, or a bit close, but you will never have an exact replica. This is what the merle gene does. If the dog who had has the merle gene was black, it is called a Blue Merle. With out the merle gene it would have been an all black dog. Since the places that merle gene lands are rather random, you get all different looks. Patches, dots, spots, bands for example. If the gene lands in the eyes, we get beautiful and highly desired blue eyes! If the gene lands enough on the nose, especially with a few other genes in the mix, you get pink on the nose. The merle gene, when you get on the DNA level, does not sit on the Agouti location in the allele. (Fast break down - DNA has many loci for one and locus for several. At these "locations" sit allele's and on these alleles we find markers that tell us this color or pattern lives here at this location.) In the case of merles it is a color dilution, not a pattern gene. This means is can overlap or be on dogs who have genes that have patterns. In Pomeranians this means merle can also be on a dog that is Black and Tan, or Parti, or a dog that has a double pattern of Tan and Parti - normally called a Tri-Colored.
What is all this stuff floating about saying merles are deaf, or sick or something else horrible if it has a cream or white parent?
A great deal of confusion comes in here! One myth is that it is the end of the world if a Pom has a white or cream parent and a merle parent. This is just silly and, while it might not be our first choice of a mate, it will not harm the puppies in any way. Just because you see a white coat on a Pom doesn't make that dog a genetically white dog. (That is another gene, for another discussion.) For the purpose of this one, you are seeing a white Pom, who's DNA says it is a black dog under that white coat. So using that dog as a mate for merle is no less of a problem than if the mate showed a black coat. Frankly, or a chocolate, coat, or a blue coat, or any other color except another merle. There is no cause to panic if you have a merle with a cream or white parent. Unless a sable gene was in one of the parents, the puppies will still be very nicely marked merles. The sable gene in Poms, (ay) if you wish to get specific, does change around the coat color in Poms.
Where did the myth and fact of merles having awful defects come from, or horrible health issues?
In a few breeds it seems that merle to merle breedings are frequent. Because I have studied the pedigrees, some of those dogs were then bred to merles again! So now the gene has been doubled, or tripled. Why on Earth would anyone doubling the merle gene if there is a risk of a problem? In a few breeds I have seen where the only way to save a very good, and rare bloodline, was to take that risk. That was that particular breeder's decision. I know of once case where it produced a male who almost all his children became Champions. How is that possible when he was blind or deaf? Because it is only the doubling, or even tripling of the gene that causes the issue. A deaf or even blind double or triple merle bred to a non-merle can not pass down any of the defects that were caused by adding the merle gene in extra times. It is not like a non- merle that has a genetic eye issue that is in all or part of the puppies and it could be in a great many dogs in that bloodline. In these cases the issue with the dog is present because the merle gene was increased to the point that it caused a risk. A merle bred to a non-merle will never ever have this risk. A normal merle has no greater risk of health or eye issues or anything else than any other dog. The merle gene doesn't make a dog sick - it makes it have a special look to the coat.
These studies and articles say that merles are deaf and have eye issues, what is this really about?
I'm reading yet more articles that are saying merles have higher ratios of partial deafness, or eye issues. What makes me so irritated with these articles is that NONE of this research starts with the fact that almost all dog breeds have hearing and eye issues in the breeds. So they don't even take into account the existing percentages in each breed of hearing and eye issues BEFORE they start checking to see what the merle gene really did, or did not do. Instead, these test lump multiple breeds and run batch results with out taking the over all breed statistics into account prior to this! These "results" lack comparing each breeds standing deafness and eye issues to the results, and it all gets blamed on the merle gene. That just isn't even a good solid study to begin with. To make matters even more complicated, hearing and eye issues vary in how drastic they are per breed. Lumping multiple breeds together like this and passing out results is an incomplete and incorrect way to distribute "results". If they wish to give us more solid results then a very long and through study of hearing issues must be accomplished in a breed, and then after those results are correctly compiled then they could be compared to hearing or eyes in merles of that same breed only instead of mixing it all up with nothing solid to compare to. Again, I will reiterate that my merles have all their hearing, and vision!
Myth - all the puppies in a litter by one merle parent are merle or carrying merle.
Frankly this defies logic and genetics as well. A litter of puppies from a mating where one parent is merle, and one is not - will produce merles and non-merles. There is no in between. There are no "cryptic" merles this way. There are no "phantom" merles. There is nothing to fear if you pay attention. :) Let me make this VERY clear- there is NO MERLE FACTORED. If someone tries to place a merle factored puppy with you, you are being scammed. If a breeder is very scared, there are simple DNA tests that will tell you if you missed it somehow and can't tell a merle from a non-merle. You can NEVER get a merle from a non-merle. I know people who didn't understand and tried. It is like saying my dog is a purebred Pomeranian and a merle factored (that doesn't exist!) and if I breed it I will get a pure-bred Great Dane puppy! I know that is way out there but I'm wanting to make this really clear. You wouldn't expect that to happen because it isn't possible. It is also not possible to get a merle out of a puppy from a merle parent that did not get the merle gene. If the puppy didn't have merle when it was born, it will never be a merle. It will is considered a "solid". By solid we do not mean it doesn't have a pattern, but that is is devoid of the merle gene.
Where did these terms, phantom, cryptic or merle factored even come from?
I have not seen these terms outside of the Pomeranian breed, though I could have missed it somewhere. It had to have come from the unique things we have in Poms. The sable gene (ay) changes as a Pom grows. A pup with so much black on it's orange coat is almost all orange or only has a few dark whiskers when grown sometimes. When a merle Pom is an orange or red, the sabling that had the merle on it grows off and confuses folks. This isn't as bad if they have blue in their eyes, people can still look at them and know they are a merle. However, if they are pushing towards the new APC/AKC standard change for the Poms the eyes are brown and now folks are scared and panicked. This, in my opinion, was not a smart over-all move. I prefer the blue eyes in my merle Poms and I will continue to love the blue eyes because I always have loved blue eyes in all living things.
Myth - If I see a pedigree with several merles in it - they are all doubled and the person is an unethical breeder.
Should you become inspired to learn and start reading the pedigrees of many breeds and see that merles are in the pedigree over and over, it is not a cause to panic! If you read that those merles were bred to non-merles and a merle baby was kept and bred to another non-merle - there is NOTHING wrong with this. In these cases it is just the same as if you had many many black, or black and tans, or oranges or any other color in the pedigree. If you find several merle to merle breedings, then that would concern me personally, but again, if those double merles were bred out to "solids" there is probably a reason. If you can, ask the breeder and talk to them with armed with knowledge and not myths.
Fact - Merles do not look right bred to a sable.
If you breed merles to sable colored Poms, you get "muddy" merles. That means, they are more brown and less merle. If they are red sables or orange when the dog is a merle - all the merling will grow off the coat. This ties into the other information in this article.
What other observations have you had in your time with merles?
SMART! Oh my goodness, these dogs are SMART! I'm not saying other dogs aren't, nor that other Poms aren't, but these dogs are just super smart! They figure out logic games quickly. They are curious about all sort of things around them and mine are very agile as well. They can have a higher pitched bark, but in mine I have worked away from that as much as possible.
Merle photos are all through my site, and I might make a merle photo gallery.
As ALWAYS with me, Please feel free to ask questions! Carol :)