Merles and the Merle Gene
is no such thing as a
sable merle gene or a red or blue merle gene.
is only a merle gene.
Merle is an INCOMPLETE DOMINATE gene, which means this gene will
up in it's offspring. Merle is also a dilution gene,
is, it lightens
whatever the coat color would otherwise have been.
lightening is not spread
evenly over the coat, but leaves patches of undiluted color
over the dog's body. Also, the lightening seems to work primarily
the black pigment in the coat, so any tan on the face stays even.
that "black" as
used here includes the brown color.
dose of the merle
gene on an otherwise black dog produces a blue merle - a more
less bluish gray dog dappled with black spots.
points - the tan spots
over the eyes, on the sides of the muzzle, on the legs and under the
of a tricolor dog - will still be there in the merled tricolor.
tan spots would not
be present in a black dog, tan will not be present in the merled black
either, and the dog will blue merle and white without tan.
dose of the merle gene
on an otherwise sable dog produces a sable merle.
merles are less predictable
in color than blue merles, and may range anywhere from an apparent
often with a pinkish or orange cast to its coat, to something
looks like a very rusty
blue merle. White markings remain on the merled dog, and may even be
acts on the dark
pigment in the iris of the eye just as it does on the coat, so merle
often have part or all of the eye blue.
(This does not affect their
though since it
happens to some extent in the retina as well it may make it harder to
certain eye problems.)
what was said was
single dose of the merle gene. There are always two copies of a
alike or different, in any dog. If we call the merle
and the non-merle
gene m, any given dog can be
mm, Mm or MM.
dog is the normal,
full-colored tri, bi-color, or sable, or liver (red) in Australian
The Mm Cocker is a blue merle, or brown merle, etc,depending on
color it would have been without the merling gene. An MM dog, often
called a double merle or a homozygous merle, will be mostly white
sometimes deaf or blind and often with other physical problems.
MM puppies are born
completely without eyes.
average, over a large
number of litters, breeding merle to merle will produce one fourth full
colored dogs, one half merles and one fourth defective whites.
merle to full color
will produce one half full color and one half merles, but no defective
whites. The merle to full color breeding, then, produces just as many
as does the merle to merle breeding, and without the danger of
puppies. The safe breeding for a merle, then, is to a non-merle
breeding should produce
healthy puppies, and about half will be merles.
breed in this way,
it is important to know which dogs are merles.
is one of the reasons
experienced breeders rarely breed blue merles to sables, or roans as
mating may produce sable merles or merles to the
to appear incorrectly as roans..
merles are no more
likely to have health problems than any other color.
you cannot tell
a sable is a merle unless you see it on the
tips of it's ears or the
eye or eyes are blue or blue flecked.,. The real argument against
sable merles is that they may be mistaken for normal sables.
such sable merles were mated together, the resulting litter could
sable gene can also
mask the merle, and as the dog ages it may be next to impossible to
by looking that this IS a merle dog.
is one kind of breeding
that can produce all or almost all merles, and that is the breeding of
a tricolor or a bi-color to a double merle - but remember that the
merle in other breeds, has a high probability of being blind or
few breeders have been
lucky enough to get high quality homozygous merles that are not too
affected to breed - but it definitely takes a lot of luck and really
quality blue merles to start with. Merle to merle breedings are only
the very experienced breeder who knows their lines and what they will
- and it has probably produced more heartbreaks than good homozygous
even for them.
merle from black
to homozygous merle breeding is just as healthy as one from a more
black to blue merle breeding.
you have done a
lot of merle breeding and really know what you are getting into, the
rule is still that a merle should be bred only to a solid color
double merles, you
would actually have some normal colored hair, some diluted hair AND
double diluted hair. Each merle gene would dilute hairs in their
own pattern and that those patterns might or might not overlap.
you can have 3 different colors of coat (normal coat, diluted coat and
double diluted "white") coat on a genetically SOLID dog! With
the dogs could be almost or even entirely white since they already have
large areas of white.
Cockers have a spotting
gene which can leave only small amounts of color on the dog, we can't
that a merle with a lot of white is actually a double merle. A
single gene merle parti-color dog can have any amount of white that is
normal for a regular parti-color. We can have very open-marked
Cockers and they are no more at risk to be defective than a normal
of this next article
was borrowed from another site
article explains the
basic genetics about merling in easy to
avoid confusion, the
was changed to merle
in the article.
double Merle and how it happens
is important to understand
that merle is NOT a color, it is a pattern
compared to painting a room in your house. Say you paint the room
the paint is
allowed to dry, you dip a sponge in white paint and then dab the walls
with the sponge.
each spot that
the sponge touches, you will have a lighter green marbling affect that
results from the green and white paint blending together.
works in precisely
the same fashion. The merling can occur on any color.
merle black Cocker would
leave a black base with a gray marbling affect. A merle brown Cocker
result in a pinkish/tan or cream marbling affect.
where the merling
chooses to occur is anyone's guess.
litter of puppies,
you can have puppies that are merled from nose to tail or you can have
puppies with nothing more than a merle splotch on the top of the
merled puppy can
go on to produce lightly merled puppies, just as a lightly merled puppy
has an equal chance of producing heavily merled puppies.
is never rhyme nor
reason to how the merle gene chooses to act on a puppy. There are
breeders who have worked to understand the gene
how it works.
also put much into
their program to produce healthy dogs, but, these breeders are far and
few between. IRRESPONSIBLE breeders have caused most of the
does it work?
mentioned earlier, is a pattern. When two Cockers breed, they
contribute to each puppy's gene pool. Have you ever played the
"War"? In the card game both players are dealt an equal amount of
'one' flips one card over and Player 'two' flips one card over.
player with the highest value card takes both cards and puts them in
game continues on until there are no cards left in either player's
can compare the genetic make-up of a puppy to a game of "War".
dam flips over one gene*, and then the sire flips over one gene.
'higher' valued gene (dominant) goes into the winner's pile.
'lower' valued gene (recessive) goes into the the loser's pile.
the game is over, the dominant pile is made up of the genes that
to the 'outside' of a puppy....those things that we see.
recessive pile is made up of the genes that contribute to the 'inside'
of the puppy...those things we can't see.
that puppy is old enough to breed, the dominant and recessive genes are
shuffled and a new game of 'War' begins.
the card game, you can sometimes have a tie, both players flip over the
same card of equal value.
can also happen with genes in a puppy. In the card game,
is declared and there is a 'showdown'. However dogs have never
known to be as competitive as humans are...dogs simply call it a draw.
anyone's guess whose gene (the sire or dam) gets to go in the winner's
pile, but it is really irrelevant, since both genes are identical.
are thousands of genes involved in the make-up of a dog, from the shape
of his ears to the length of his tail. There are
known genes that contribute to coat color/pattern in dogs.
gene for merle is dominant over the gene for non merle.
an example, we'll say that the sire flips over the merle gene and the
flips over the non merle gene. The two genes are compared and
merle gene goes into the winning pile...the part you will see on the
non merle gene will go into the losing pile...the part you don't see on
time a merle gene is passed on to a puppy, that puppy will be merle
a merle gene will always be dominant.
of you that are familiar with genetics,
wanted to mention that
many times the word 'Gene' is used in
of the proper term,
"Allele". I feel that describing alleles will only
the average viewer
and the point can be made by substituting the word 'gene'.
is a Double Merle?
both the sire and the dam of a puppy are merle, they both have an equal
chance of passing on their dominant merle gene to the puppy.
sire may flip over the merle gene, and the dam may flip over the non
this case, the sire's merle gene would be dominant and that puppy would
be a merle.This confuses a lot of people. How can a merle dog
a non merle gene?
is easy to forget that every dog has a winning pile...what you see on
outside, and a losing pile...the recessive gene that is hidden.
each dog only
one gene to contribute, there would never be variety in the dogs. When
two dogs breed, the recessive genes are shuffled with the dominant genes
that they have a chance to manifest themselves. If the recessive
gene meets up with another recessive gene, it finally gets its chance
be in the winning pile.
if the recessive gene again meets a dominant gene, it has to wait
generation for the chance to dominate.
is also possible for
both the sire and the dam to flip over their non merle genes. If this
the case, it becomes a 'draw' and the puppy is not merle.
finally, it is possible for both the sire and dam to flip over their
it is a draw, but something totally different happens.
say that the sire's merle gene gets to go in the winning pile.
puppy is now merle. But the dam also contributed a dominant
gene says, "Whoa, wait a minute buddy!
do you think this is, the 19th century?
demand equal rights here! I want a chance to merle this puppy and
the 19th Amendment guarantees me that right!"
the dam's merle gene goes to work, after the sire's gene has already
the puppy merle. Since it's anybody's guess as to where
merle gene will hit (remember the sponge painting earlier?), the
will vary greatly. We'll assume, for ease
the sire merled the tail, and nothing more. The rest of the puppy was a
normal color and untouched by the merle.
dam's gene is mad at almost missing out on her chance, so she merles
entire body...from head to tail. The areas that the sire's merle
gene left untouched would now be merled by the dam's merle gene.
the area that the sire's gene did merle (the tail) would be merled again.
go back to the paint. You finished the first coat of green and
finished sponging white paint over the wet green paint.
dip the sponge in the white paint again. What do you think will
when you start sponging the walls again? The areas that did not
touched by the first sponging, would now have the marbled look, but the
areas that were marbled the first time would now appear totally white.
is precisely what
happens when the merle gene is allowed to act twice on the same
What's Wrong with a Double Merle?
reasons unknown, the combination of two merle genes hitting the same
of the dog can be lethal. I have seen
with no eyes, and/or no ears. Blindness and/or deafness is
also caused by the double merle gene.
the other hand, a double merle can be born with no deformities at all.
are no facts or
figures available (that I have found) that tells us how many dogs like
this dog have been whelped. The double merle pattern is an
pattern in some breeds that is recognized by AKC. In my
if AKC continues to allow this pattern (which can only be achieved by
two merles together, so it is totally preventable) to be recognized,
serious studies should be done to look at the damage being done to the
Would Anyone Do This?
every deformed double
merle, there is a different excuse.
are a few of those
'excuses' and a few solutions.
Simple ignorance: Genetics are a complicated matter and many
won't even take the time to try to learn.
TAKE THE TIME TO LEARN!
are two foundation
books on genetics.
excellent books but both are out of print. Try your local
of the Dog: Malcolm Willis"
Inheritance of Coat Color in Dog: Clarence Cook Little"
background unknown: Although the only way to get a double
merle is to breed two merles together, there are
many people that don't
they own a merle..since AKC has only allowed and has
Cocker breeders to register their merle cockers as ROAN,
it can be very dangerous and heartbreaking for those who are uninformed
Some merled dogs often fade as they get
older. A dog that was poorly merled
at birth, and is sable or some other lighter color, will probably
be recognized as a merle later in life.
Don't breed lighter colors or sables to merles.
you do, make sure you YOU UNDERSTAND genetics and the merle gene and
it works, AND BE ABSOLUTELY SURE to examine every puppy from head to
is when the merling is most noticeable.
sure to mark a puppy as a merle, even if it has no hint of merle at
weeks of age. CHECK the eyes!
the eye or eyes are
a lighter blue than normal puppy blue eyes, or have specks of blue in
safe and consider this dog a merle!
Other colors of merles are often so lightly merled, they are not
marked as merle on their papers. In the case of Cockers, again,
registering them as Roans, and every effort MUST be made to get ASC to
allow the merle pattern so AKC can register these dogs as merle.
Again, be sure to record merles at
good sign of a merle (assuming one of the parents was a merle) is if a
puppy has any blue flecks in the eyes. The merle pattern can
of the eyes, just as it covers the color of the coat. When the
pattern hits the iris, it turns it blue, like that of a Siberian
the merle pattern is so sporadic, it can hit just a spot on the
a normal color eye with a tiny blue fleck. Always mark blue
blue eyed pups as merle if there is even the slightest chance that it
If you aren't sure if your dog is
double merle, look at the pedigree!
THE BREEDER your dogs came from and ask them! Make sure the dog
is a merle and not called a roan .A
merle will always have a
dam and a merle
sire. ONLY TWO MERLES can produce a
ultimate test of
a double merle is to breed it to a SOLID colored dog.
ALL the puppies are
merle, your dog is a double merle!
ON THE BANDWAGON AND CONVINCE THE AMERICAN
CLUB TO GET THESE DOGS LISTED WITH AKC AS MERLES AND NOT ROANS OR
Some Other color without adding the merle pattern!!!!
If we go back to the genetics behind a double merle, you will remember
that a double merle results when two merles both contribute their merle
gene to one puppy. That puppy, if he goes on to breed, will have
two merle genes that will be shuffled and eventually dealt out into the
the merle gene is an incomplete dominant, and the only thing that
puppy has is a merle gene, there is a 100% chance that every, single
that dog produces will be a merle.
other words, a double merle will ALWAYS produce merle puppies,
when bred to a normal color dog (black & tan, chocolate & tan,
merle puppies can command a higher price, due to it being "RARE", there
are breeders who purposely breed merle to merle, in hopes of getting a
double merle. That double merle can then be used to
all merle puppies...all of his life.
is interesting to note, that even a dog which is totally blind and deaf
will NEVER produce a deaf or blind puppy (providing that he isn't bred
to another merle or carrying some other genetic defect that causes
deafness/blindness seen in double merle is only a result of the two
is no solution for this sort of breeder.
is more powerful than compassion.
Can I Help?
double merle deformities
are not seen just in Cockers.
I mentioned earlier,
the pattern is seen in several other breeds of dogs.
the word our about irresponsible breeding of merles is important.
of you are in large cities where you have the ability to get the word
about the possible dangers of double merle
of you attend dog shows regularly and can pass out literature (feel
to print this article) to people at the show.
as simple as scanning the internet for breeders selling double merles
sending them the link to this article, can go a long way to educate a