Merle spaniels

The Truth Behind The Merle Cocker Spaniels Controversy

Trying to discuss merle Cocker Spaniels is the canine equivalent of yelling “fire” in a crowded theatre. Panic starts, tempers flare, and chaos ensues. Why is there so much controversy around the breeding of merle Cocker Spaniels and why does it matter?

Merle Cocker Spaniel dog rescue
Photo courtesy Cocker Spaniel Rescue of East Texas, Sarah Renee.

The Truth About Merle Cocker Spaniels

Cocker Spaniels come in three color varieties but there are many other colors that are not considered “breed standard.” The breed standard is a set of guidelines animal fanciers use to ensure a breeder conforms to the specifics of that particular breed. In other words, it’s a written description of the ideal specimen of a breed.
Standards apply to type, structure, gait, and temperament. The American Kennel Club says a Cocker Spaniel must be “free and merry” as part of its breed standard. The American Spaniel Club recently published Blue Book, The Study of the Cocker Spaniel, which illustrates and outlines the breed standard.
The Cocker Spaniel’s standard for colors and markings per the American Spaniel Club are:
  • Black variety: Solid color black to include black with tan points.
  • Any solid color other than black (ASCOB): -Any solid color other than black, ranging from lightest cream to darkest red, including brown and brown with tan point
  • Parti-color variety: Two or more solid, well-broken colors, one of which must be white; black and white, red and white (the red may range from lightest cream to darkest red), brown and white, and roans, to include any such color combination with tan points.
  • Tan Points-The color of the tan may be from the lightest cream to the darkest red and is restricted to ten percent (10%) or less of the color of the specimen
Merle is not listed in the breed standard for color because merle is not a Cocker Spaniel color.
the truth about merle cocker spaniels

What Does Merle Mean?

UC Davis Veterinary Genetics Laboratory defines merle as “an incompletely dominant coat color pattern characterized by irregularly shaped patches of diluted pigment and solid color. Breeds with merle include but are not limited to: Shetland Sheepdog, Collie, Border Collie, Australian Shepherd, Cardigan Welsh Corgi, Catahoula Leopard Dog, Dachshund, Great Dane, Bergamasco Sheepdog, and Pyrenean Shepherd.”
Dr. Jeanne Grim, a practicing veterinarian with 32 years experience says merle is not a Cocker Spaniel color.
“Merles were mixed into the breed by a cross, most likely with a Sheltie,” she states. “That’s why ‘keepers’ of the breed are so against this.”
By mixing or crossing Cocker Spaniels with another breed, the result is the merle pattern we see today. I asked Caroline Coile, Ph.D., award-winning author of 34 books, one of them on Cocker Spaniels, her thoughts. Coile specializes in genetics and DNA, veterinary topics, breeds, and neurosciences to name a few.
Coile says it’s much too late for DNA testing for breed purity in the merle Cocker Spaniel to be of help.
“If the cross was made in the 1980s, and the offspring bred back to Cockers each generation, you couldn’t tell their DNA apart from a pure Cocker,” she shares.
A standard merle coat has two characteristics: a diluted base color and random patches of full pigmentation.

blind merle cocker spaniel
Meet Jamie. Photo courtesy Brenda Maeder.

What’s The Problem With Merle Cocker Spaniels?

Those who rescue merle Cocker Spaniels have something to say about breeding them.
Brenda Maeder of Hyde Park, New York, has privately rescued dogs for over 40 years and has worked with rescues for eleven. Maeder is the author of Jamie’s Journey, the true story of a blind and deaf dog that is challenging to teach. She rescued Jamie from North Shore Animal League almost three years ago. Jamie is Maeder’s first Cocker Spaniel and a true double merle offspring.
merle cocker spaniel book
“When two merles are bred, they have a 50 percent chance of getting [these] unusual colors and a 25 percent chance of producing a dog that carries the double merle gene,” she states. “The double merle gene brings with it hearing impairment and/or eye issues.”
Many merle Cockers are both blind and deaf like Jamie. She says many times, breeders destroy them before the public is aware they exist. The “lethal whites” are what some breeders call them.
Maeder visits two veterinarians in two different areas 100 miles apart. Both vets tell her the merle gene causes eye and ear issues.
The problem with the merle pattern in Cocker Spaniels “is that it more likely entered the gene pool by way of crossing with a merle dog of another breed,” according to Dr. Coile.
Coile’s biggest issue is the double merle, like Jamie, which can produce a deaf and/or blind dog.
According to Coile, “Merle is a dominant allele and (with the exception of the unusual cryptic merle) would have been expressed had dogs with the merle allele been around in earlier times.”
She says merle does not easily appear by mutation.
“In fact in every breed that has merle the mutation causing it has been the exact same mutation, suggesting it was a one-time event that happened well before the development of these dog breeds,” Coile reminds.
Double merle pups are born when both parents are merle, but what happens if both parents aren’t merle?
American Spaniel Club

American Spaniel Club’s Stance On Merle Cocker Spaniels

Established in 1881, the ASC is the parent club for the Cocker Spaniel. They focus on responsible breeding, care, health and training of all Spaniels, with special attention to the Cocker Spaniel.
According to Charles Born, Past President, the ASC Foundation conducted a three-part study:
  1. Researching the evidence showing whether merle is or is not a Cocker Spaniel color.
  2. Researching the scientific evidence that the merle color can produce significant health issues.
  3. Developing an approach for educating breeders, owners and the general puppy buying population on the results of their investigations.
In a nutshell and layman’s terms, the study concluded:
  1. Is Merle a Cocker Spaniel color? The merle mutation predates all dogs and is behind all breeds—quite possibly going back to their wolf ancestors.
  2. Does the merle mutation pose a health risk? While not every single merle Cocker has health issues, the preponderance of health issues directly and specifically associated with the merle genetic mutation has been identified in the peer-reviewed scientific studies highlighted in the study by the task force.
Further, the American Kennel Club-Canine Health Foundation (AKC-CHF) lists merle as a disease for which there is a genetic test. As a result, the AKC-CHF concludes that merle is detrimental to the breeds.
In their conclusion, the ASC specifically states, “Breeding merle to non-merle has similar health risks although the incidence is reduced.”
ASC also concludes breeding merle dogs introduces the offspring to deafness, blindness, and even alopecia along with other health problems that may lead to death.
Most striking is the ASC’s conclusion that a cryptic merle mutation exists and because it is not visually apparent, it introduces significant health risks to the offspring.
ASC encourages responsible breeders to perform a DNA test for the merle mutation, as a cryptic merle may not show merle phenotype but can produce merle offspring.
Clear as a spring day, right?

Devoted Breeders Stance On Merle Cocker Spaniels 

Lisa Gaertner is a Cocker Spaniel breeder, owner, and handler and the founder of Pinecliff Cockers. She’s owned Cockers for over 30 years and began breeding and showing them 12 years ago.
“The general public who sees these puppies cleverly marketed as ‘unique’ or ‘rare’ don’t realize the risks involved,” she shares. “There will only be merle breeders as long as there are buyers who have not educated themselves on the problems they are getting themselves into.”

Lisa Gaertner Cocker breeder
Photo courtesy Lisa Gaertner.

For over 25 years, Kim Vavolo has been breeding and showing Cocker Spaniels. She says the biggest controversy, besides health issues, is that a merle Cocker Spaniel is not a purebred dog.

“Merles came from introducing another breed into Cockers to get the color, so no, they are not truly purebred,” Vavolo reports. “A merle bred to a merle can even produce offspring with no eyes.”

Nicole Tehranchi is a 35-year Cocker Spaniel owner and became involved in canine conformation 22 years ago. She’s bred a few litters and shows dogs as well.

“There is much controversy with breeding merles because it’s not an allowable color,” Nicole shares. “Up until 11 years ago, you really couldn’t register a merle Cocker.”

cocker spaniel blonde
Nicole Tehranchi and her Cockers

Nicole says the merle color is not that of a sporting dog and is usually found in Aussies, Collies, Shelties, Corgis, and Catahoulas.

“Yes, I do see them being more prone to health issues. Some include deafness, blindness, skin cancer, micro-ophthalmia ( born without eyes or very little eyes), color dilution alopecia, and cyclic neutropenia ( gray collie syndrome: eye, skin and bleeding issues) as well as death,” she shares. “While not every single merle Cocker has health issues the preponderance of health issues and directly and specifically associated with the gene has been identified.”

A Merle Cocker Spaniel Dog Owner Speaks Out

Donna Zygarlicke acquired her first Cocker Spaniel in 1990. Flash forward where she is the proud owner of two merle Cockers.
She believes merle Cockers are “as healthy as normal Cockers as long as the breeder knows not to breed two merles together.”
Better breeding practices and understanding of merle Cockers are important to her. She says there are many bad breeders who breed dogs with a myriad of health issues.
Author’s note: For the sake of this piece, we are focusing on merles but agree that there are bad breeders who have no business producing puppies for a profit with zero concern for the breed, Cocker Spaniel or otherwise.
“Neither of my merles (ages 2 and 10) has health issues,” Donna adds. “My first merle had parvo as a puppy, not merle related, and ended up passing from lymphoma at the age of 10, again not related to being a merle. She was a very healthy dog otherwise.”

Merle Versus Roan Cocker Spaniels

Caroline Coile, Ph.D., writes in The Cocker Spaniel Handbook, “Your Cocker Spaniel’s color depends on the interaction of many genes, some of which mask the actions of others and some which modify the action of others.”
I spoke to a Cocker Spaniel breeder who did not wish to be identified but has decades of experience with the breed. Said breeder wants the roan distinction made.
“In your exploration and writing about the merle issue, please make note that roans are different even though they may look similar to some people, breeder states. In a Facebook group recently, it took days to convince someone who was actually breeding her merle that he and his offspring were in fact, merles and not roans.”
She wants everyone to know that roans have zero health issues associated with the pattern and represent a safe alternative to those who like their Cockers fancy.
The AKC breed standard of the Cocker Spaniels, with regard to color, has this to say: 
Parti-Color Variety: Two or more solid, well-broken colors, one of which must be white; black and white, red and white (the red may range from lightest cream to darkest red), brown and white, and roans, to include any such color combination with tan points. It is preferable that the tan markings be located in the same pattern as for the tan points in the Black and ASCOB varieties. Roans are classified as parti-colors and may be of any of the usual roaning patterns. Primary color which is ninety percent (90%) or more shall disqualify.
For those not dedicated to the fancy or breed standard, roan is generally described as a mixture of pigment of fur that is both white and another distinctive contrasting color, which does not fade or turn grey or white when the dog reaches his or her senior years.

roan cocker spaniel
Roan Cocker Spaniel


The Battle And Truth About Merle Cockers 

Long-time breeder/handler, Marlene Ness says merles are a very sore subject for many involved in the breed.
“Merle is popping up in many breeds where it is not a recognized color, so many of us are battling it,” she muses. “It’s hard to battle the backyard breeders who sell them for big bucks.”
Merle is an appealing pattern to some prospective pet owners, but there are health risks even with one copy of the merle gene.
According to AnimaLabs, which focuses on DNA testing of inherited diseases and appearance traits, precise identification of infectious diseases and scientific evidence of the pedigree of pets and domestic animals:
In both heterozygous ( genotype Mm) and homozygous (genotype MM) merle dogs eye and ear abnormalities have been observed, which included deafness, increased intraocular pressure, bad reflection ability (ametropia) and coloboma ( a hole in one of the structures of the eye). The absence of pigment affects also hairs in the inner ear, causing complete deafness. Research proved a deafness prevalence of 54.6% in double merles and 36.8% in single merles.
There are thousands of genes involved in a dog’s DNA from those that shape her ears to those that determine his tail length. There are seven genes that cause specific coat colors and/or patterns in dogs.
The battle wages on because there is a passion and devotion for the Cocker Spaniel. Everyone wants a happy, healthy Cocker who lives a long, healthy life. I am not a geneticist or veterinarian, but I am a dog writer, blogger, Cocker Spaniel owner of close to three decades, and I advocate for both reputable breeders and reputable rescues.
There’s a lot of diversion from the breed and that’s why credible breeders are needed. Dogs of all shapes and sizes, many with health issues, wind up in shelters or ultimately losing their lives through no fault of their own. That’s why credible rescues are needed.

Merle Cocker Spaniel puppy
Merle puppy. Photo courtesy Kimberly Joy Perfetti, taken at a pet supply store.

Bottom Line

A reputable dog breeder will answer your questions and screen you as much as you screen them. Ask questions, do your homework, get to know more about puppy or dog you are purchasing, and get references from other buyers. It is perfectly okay to purchase a dog from a reputable breeder. Here’s how to identify a reputable dog breeder.
Please don’t purchase from a puppy mill, pet store, or someone you have little information about. If you are the proud owner of a rescued merle or in some capacity have a merle dog at present, this article is intended to inform based on the information available. A lot of folks do not realize what can happen when merles are bred. This post is designed for education and the truth about the cocker spaniel merle controversy.
When good dogs (and aren’t they all) end up with bad people (so many out there), guess who often pays the ultimate price? Dogs do, with their lives. Not all dog rescues are created equally, so it is up to you, the prospective dog parent, to perform due diligence in finding a reputable dog rescue. < ==== here’s how. 
My stance is dogs matter and those who hurt dogs in any way, shape, or form, need to be stopped. Knowledge is power. Dogs’ lives depend on us to do the right thing.

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  1. We had a Silver.white Merle for over 12 years. At the age of 11 she developed Glaucoma in one eye which we had removed so she had no pain. During that last year she went blind, deaf and heart failure and we wound up having to have her cremated. What a Blow! We had rescued her at a goodly price after her owners bred her before she was one year. We immediately had her spayed and she was our pride and joy until that last year. So we figured it was due to poor breeding among merles and cockers. Would never own another one simply because it is not healthy.

  2. Although I’m a cat parent, I’m still a dog lover and it breaks my heart to see what some breeders are doing to purebred dogs for the sake of making a profit. I have volumes to say about French bulldogs and Cavalier King Charles Spaniels for that reason, but since this article is about Cockers, I’ll save my rant for another website. Anyhow, I’m glad you’re bringing attention to the controversy about merle Cockers and the health risks that come from irresponsible breeding. Thank you!

  3. We got our first cocker spaniel 10 years ago. Cody is 10 now. We were told his coloring was merle. Reading this article I saw a picture of a cocker that looks exactly like Cody. He was referred to as a roan cocker spaniel. How can I find out if Cody is roan or merle?

    1. I am not disputing that a specific dog was introduced into a cocker spaniels line. But merle is not a color more to the absence of color. It is a recessive characteristic of its genes can happen to human beings and can happen to basically any species of life. My Lady has one brown eye and one blue. If you breed Burroughs you’ll basically end up with a blind and a deaf litter not to mention other health issues. But my merle cocker spaniel is, a purebred cocker spaniel!

    2. you can do color DNA testing to see what genes he has
      Pawprint genetics and GenSol both do color testing.
      you can pick the genes for merle and roan and test specifically for those 2

  4. No good ethical breeder breeds merle cockers. Should always research a breed before buying a puppy. Make sure they breed in the standard, standard colors, build and temperment. That they do all the health tests recomended for the breed. I had a byb cocker. He had heriditary gloucoma. He had to have an eye removed and was blind in the remaining one. He ended up with lots of tumors and lost him at ten. I have a well bred roan from health tested parents and champion lines. He’s pretty, healthy and so playful. Wonderful dog.

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