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One of the most unique aspects of Chihuahuas as a dog breed is the wild variation between different pups. Some Chihuahuas are short-haired, some are long-haired, some may have different head shapes, and some may even be blue!
Many potential chi-owners seek rare color and marking combinations when looking for a new Chihuahua, and Merle Chihuahuas are among the most distinct and sought-after coat patterns.
Check out our main post that showcases all our Chihuahua fact articles!
Merle, known sometimes as “ dapple ” in other breeds, refers to a spotted or mottled coat pattern. The pattern extends to the dog’s base coat and skin. However, there is far more to Merle Chihuahuas than meets the eye.
In this article, we will break down everything that you never knew about Merle Chihuahuas, from the trait’s spotty history to the current controversy surrounding the pattern. Let’s count down seven facts that you never knew about Merle Chihuahuas.
1. MERLE IS A GENE MODIFIER
When it comes to the Chihuahua breed, Merle is not just a beautiful and unique coat pattern. Merle is actually a gene modifier. In layman’s terms, a gene modifier is a gene that affects how other genes express themselves.
This means that the Merle gene affects more than just coat color. Often, the Merle gene affects the dog’s skin pigment, resulting in light and dark spots beneath the coat. Likewise, the gene can even affect eye color.
2. MERLE CHIHUAHUAS CAN HAVE BLUE EYES… AMONG OTHER TRAITS
Yes, you read that correctly. Some Merle Chihuahuas have blue eyes, and some have one blue eye only.
This phenomenon is called heterochromia. A Chihuahua with one or more blue eyes will have an increased sensitivity to sunlight.
Unfortunately, the Merle gene modifier also causes some undesired health issues.
Merle Chihuahuas are more likely to develop hearing and vision problems. These issues will be present when the pup is born and will not improve as he or she ages.
The light pigmentation of a Merle Chihuahua’s skin makes them more susceptible to sunburns and ultraviolet radiation.
Because of this, it is easier for a Merle Chihuahua to contract skin cancer than a standard Chihuahua.
3. NO ONE IS SURE HOW OLD MERLE CHIHUAHUAS ARE
There is a debate in the Merle Chihuahua community over how long the gene has existed in Chihuahuas.
Some parties trace the gene back 70 years to the 1940s, but others conclude that the Merle color gene has only been present in Chihuahuas for the past 15 years.
The trouble with this debate is the lack of literature on Merle Chihuahuas. There are little to no scientific articles dating the emergence of the pattern.
However, the general consensus is that Merles have been present for the last 70 years.
4. MERLE IS PRESENT IN OTHER BREEDS
It appears that sometime in the 1940s, the Merle gene was bred into a line of Chihuahuas.
The Merle color gene appears in many breeds naturally, such as dachshunds, Australian Shepherds, and Great Danes.
Many believe that because there are no records of Merle Chihuahuas before the 1940s, the Merle gene was bred into the line by crossbreeding a Chihuahua with a breed known for the trait.
5. MERLE CHIHUAHUAS CANNOT BE REGISTERED WITH SOME GROUPS
Up until 2010, the Merle Chihuahua was considered purebred and was eligible for show.
However, in June 2010, the Canadian Kennel Club and the UK Kennel Club stopped recognizing Merle Chihuahuas as purebred. As a result, Merle Chihuahuas can no longer be registered with these groups.
The American Kennel Club still allows Merle Chihuahua dogs to be registered with them, depending on a few factors.
The Chihuahua Club of America issued this statement on Merle Chihuahuas.
They still allow the registering of Merles, but “due to the number of colors and patterns occurring in the Chihuahua breed, the ethical breeding of the Merle pattern can be much more difficult than in other breeds who limit the allowed colors and patterns.”
In other words, they will still register Merle Chihuahuas, but they think there are more ethical breeds that a potential Chihuahua owner could adopt instead.
6. MERLE CHIHUAHUAS SHOULD NEVER BE BRED TOGETHER
For the sake of ethical breeding practices, two Merle Chihuahuas should never be bred together to produce Merle puppies. Breeding two Merle Chihuahuas together result in a litter of “double Merles.” Double Merles will always suffer from eye and ear issues, and some will have shorter lifespans than a normal Chihuahua.
If you would like to breed your Merle Chihuahua, do so with a standard Chihuahua.
The Merle gene is dominant, meaning that roughly half of the puppies per litter will be Merle. The Merle gene shows up the best on black-and-tan, solid black, chocolate, and blue coats.
7. THERE IS SUCH A THING AS GHOST MERLES
When a Merle Chihuahua is bred with a cream or sable-colored Chihuahua, their litter may contain ghost Merles. Ghost Merles, otherwise known as hidden or cryptic Merles, carry the Merle gene but don’t display the Merle coat pattern.
Pet owners cannot tell that their ghost Merle is a Merle Chihuahua at all. If the ghost Merle is bred with another Merle accidentally, the double Merle litter will be stuck with nasty health issues.
Therefore, if you suspect your Chihuahua may be a ghost Merle, you should have him or she genetically tested.
If you can register your ghost Merle Chihuahua, you should indicate that the Chihuahua is Merle, even if he or she has barely visible or no markings.
Doing so ensures that you are being an ethical Chihuahua owner and that you are taking responsibility for your Chihuahua’s unique trait.
Do Merle Chihuahuas Have Health Problems?
A Chihuahua with blue eyes will undoubtedly have an increased sensitivity to sunlight. The Merle gene modifier also results in other undesired health issues for this breed of Chihuahua as well. For example, these Chihuahuas are far more likely than other breeds and types to develop hearing and vision problems.
Do Merle Chihuahuas Require More Attention?
Chihuahuas, in general, are considered needy dogs, so the same applies to Merle Chihuahuas as well. They enjoy attention, being pet, and being played with. This has a lot to do with their hyperactive personalities.
What Is a Blue Chihuahua?
A blue Chihuahua is simply a Chihuahua that is just another color. Breeding a Blue Chihuahua is very difficult because the gene with the color is recessive. So, the dominant genes take over. So, it is very rare to have a Chihuahua puppy that has a full blue coat.
Why Is a Merle Chihuahua Controversial?
The Merle Chihuahua is so controversial not because of its beautiful color pattern but because of how the Chihuahua is bred to achieve that pattern. The Chihuahua does not have M (merle), and all Chihuahuas should have MM (non-merle). The president of the Australian Shepherd Health & Genetics Institute says, “the merle gene is not one that mutates spontaneously from the normal, non-merle version with any frequency.”
How is Merle Inherited in the Chihuahua Dog Breed?
Merle is simply a genetic pattern that is in a dog’s coat. The Merle gene is responsible for creating mottled patches of color in a solid coat along with blue eyes or odd-colored eyes. The gene can also affect the dog’s skin pigment as well.
What Does the Kennel Club Say About Merle Chihuahuas?
The Kennel Club definitely has a position when it comes to the Merle Chihuahua. Merle is sometimes considered an undesirable color within the Chihuahua dog breed. For this reason, the Kennel Club will no longer allow a dog owner to register a Merle Chihuahua if there is no documented evidence of the color being well-established over a sustained period of time. There are only certain breeds that they will accept Merle registrations for. As we stated above, the American Kennel Club does believe that there are Merle breeds that are more ethical.
TAKEAWAYS
The history and dialogue surrounding Merle Chihuahuas are just as compelling as their stunning coat patterns.
If your furry best friend happens to be Merle, consider yourself blessed! At the end of the day, all that matters is the adorable little Chihuahua curled up next to you.
I have just gotten my first in May. Her name is Sophie and she is a red deerhead. She is so much fun!
I love this community of Chi lovers! This is a very informative site for those of us just getting our first Chihuahua!
Sophie is a good looking chi Tawanna. So glad you joined our community!
Since this is your first chi, if there’s information you need to know but aren’t finding on this site, let me know.
Thank you Cathy for this very informative post. I have a 2 year old Merle and his name is Rio.
We live in Rochester NY.
I’ve enclosed a photo of him for you and the group ?mm
Rio is handsome. Love his cute little face Donna.
@Donna Bianchi,
Cathy, first let me say how much I enjoy your site!! I have been reading it now for several months and gobble up every tidbit of something new and pin to Pinterest!!. My ” Maddie” is 5ys old and I am so enthralled with this breed. If I could, I would have ” oodles” of them.
Thank – you for this post on the Merle gene. I found I knew less than I thought… ?. I always eagerly await your next post..
Here’s a pic of Maddie..
Oh, and speaking of the weather.. I live on the Eastern Shore of MD… close to the Chesapeake Bay.. and it’s been horrid!! Temps of 100… ” feels” like 106.. heat index 113-116!!! These are temps that MD usually does not experience.
Everyone… Stay COOL & SAFE while we have these temps across the country. AND… as always, check in on your elderly & infirmed neighbors.. ?.
I’m so glad you enjoy the site Denise and Maddie is simply beautiful!
You aren’t too far from me. I’m in Virginia Beach, a few miles from the NC border. I hear we will get a break in the weather next week and the rest of summer should have below normal temps.
Thanks Cathy for the information on Merle Chihuahuas. They are a beautiful mystery to me and I have never seen one in person. I would love to have one but it seems there are many more health issues that can crop up than the other colors. They are still so pretty, especially the blue eyes. It just kind of speaks of vision problems though. I have looked for them on chi puppies for sale sites and the are much more expensive than any of the other colors.
Yeah they are more expensive Dixie since they are rarer and many breeders refuse to breed them for ethical reasons. They sure are pretty though!
I hope someone starts up a breeders register, independent from Kennel Clubs. I have run into how dictatorial they can be and also their policies have contributed to very defective changes to certain breeds.
That would be good to have Katrina. Your chi is gorgeous by the way.
We had a Merle but back yard breaded did mom to son. Our poor girl didn’t have that great of hearing and was dead about age 5. Teeth were sideways but eat good. She was blind as had no lens ,just kind of pin holes but some how saw shadows . Best companion for my mother while she suffer with Alzhtimers .
Poor little girl. It sounds like she was very well loved though while she was here.
Thank you for this article. I have a merle that is mostly white with one blue eye. Rocky is 5 yrs old and as of right now he doesn’t have any health issues. But I do notice when he is in the sun he squints alot. In the picture he is in a camper with tinted windows where he loves to lay in the sun!
I’m glad Rocky doesn’t have any health issues. Hopefully that will continue.
Thank you for this information! My Rosa is 8 weeks, and I didn’t realise some of the background on merle Chihuahuas. She is very healthy and very loved. Looking forward to joining this community. I’m nervous!
You’ll do fine Maria and Rosa is gorgeous! Thanks for joining us.
@Cathy, I have a boy Chocolate, Tan and white merle with partial blue eyes. He is perfect and I love him. I did get him from a reputable breeder though. His name is Jax. I also have a chocolate and white girl named Penny.
They sound like gorgeous dogs!
My Oreo is a blue eyed. Blue Merle handsome 6 year old boy. He’s a very sticking very handsome boy. People stop me all the time saying how amazing he looks. He’s a deer head with giraffe legs and he looks like he trots everywhere. Lol. Loved your article, wish more people would inform themselves about chihuahuas. They are such a fun, breed with huge personalities. Lol
I bet Oreo is gorgeous!
Great article. I have a 5 year old merle, and I was thinking about getting another long-haired. Does not have to be a Merle. Don’t know where to begin looking. I have checked local rescue places. If you or anyone have any info, I would appreciate it. Thanks, Pam
Hi Pam,
I don’t know of any places to find a chi but do try petfinder.com if you haven’t already.
Also I am writing an article on how to find a good breeder so be on the lookout for that.
@Pam, I just picked up my merel today. The breeder had other puppies,but mine was the only merel.
I’m in western pa if you are interested her name
I have a “lilac Merle” chihuahua. Blue eyes.
That sounds like a gorgeous combo Desiree!
I have a merle chi thats 3 years old and have recently put down a deposit on a sister of his from same mother but she has 2 blue eyes and im kinda concerned. Is there a chance that a double merle can be healthy i habe read alot on both yes and no. Thanks
It’s possible that she won’t be healthy but then that’s a possibility with any dog. Does the breeder have a health guarantee? Many of them do.
@Stephen Arthur Nelson, 2 blue eyes is not double merle. Double is when you breed 2 merles together, that can produce unhealthy pups. Two blue eyes is fine no worries whats so ever!
I have beautiful Merle puppies from time to time. Look me up on Facebook. Tiny Paws And Tails. I’ve been breeding chi’s for 8 plus years now!:)
I have a Merle male that just fathered two puppies with a red and white and both are merles. He has one blue eye and we’re anxious to see what color eyes the puppies have. One male and one female.
I’d be curious to see what they end up looking like too Brad.
Didn’t even know that Merle was a thing till someone told my my Jack was worth a lot of money .
Yep a lot of people don’t know since they are kind of rare.
I’m in love w my merle chihuahua pups. Their father was run over by a car last week.
Oh I’m so sorry Ireri!
i have a question is there a cryptic eye in a merle chihuahua and if yes what does it mean
I’m not an expert on Merles Jocelyn but I haven’t heard of cryptic eye in merles.
@jocelyn orosco, this may help
https://www.animalgenetics.us/canine/canine-color/MLocus.asp
I got a a blue long hair deer head she is 7 months old and extremely smart was house broke in a month she is a awesome pup she gets along with my 3 other long hairs would trade her for anything
She sounds wonderful John. What do you think helped her to get housetrained so quickly?
Hi People we just got a boy Blue Merle long haired puppy Hunter he has 1 blue eye. The Breeder told us he would be registered and he was quite a bit more than the other short haired puppy supposedly from the same litter. Our Friend who introduced us to the Breeder also has an adult male with a similar Merle Coat! I feel like the breeder mislead us on the puppy. She said she will soon supply his papers. We took her on her word not thinking to research this breed. I am worried about hunter being predisposed to eye and ear problems due to him being Merle? I am not happy that she asked for more $ for him basing it on the fact that he would come with papers. Especially since our Friend with the other Merle dog paid a lot less she said because he did not come with papers! He is an amazing adorable looking puppy! This is our very first small breed dog and first Chihuahua. Just before getting him we had fostered a Shihtzu. She was a handful and we got her in line then suddenly the Family took her back which broke our hearts. I am happy to have discovered this Group. Please share with us any feed back or advice from any other Merle Chihuahua owners! Our little guy is 10 was old and we just picked him up yesterday! He is Beautiful and we are hoping for a great Family Pet. We would appreciate hearing from any other Merle Chihuahua owners! Paul R & Hunter Puppy
Some breeders do charge more for merles because they are so unusual and striking. Most likely your little guy will be healthy, you just need to be aware of what medical issues can happen.
I would limit his time outside on sunny days.
There is no evidence of more problems with a Merle
Chihuahua as long as it is a Merle and not a Double
Merle . !! Your article gives that false impression to people who do not know better .! You should correct
this false information
Sally McGinnis
Hmm, that’s not what my research shows. There is a chance of problems with any Merle but much more likely with a double merle.
I had a beautiful female merle Chihuahua who unfortunately passed away from heart problems this past March. Her name was Hope, and she was only 8 years and 5 months when she died. I miss her very much! Since health problems are mentioned, I wonder if heart issues are also prevalent in the merle trait?!
Chihuahuas, in general tend to have heart problems. I don’t think the merle gene causes it.
I have a pregnant short coat black/white female who bred with a long coat red merle. We did an ultrasound yesterday and she is carrying 3 puppies! I am excited to see what colors and coats they are.
Congratulations! Let me know what they turn out to be.
I have a blue merle with one blue eye and one brown. I’ve had him since he was weened. He has his own facebook page with over 5000 friends WORLDWIDE search “Merlin the blue merle Chihuahua”
I know that page! Here’s a link in case anyone else wants to check it out: https://www.facebook.com/Merlin-the-Blue-Merle-Chihuahua-1462729360625491
Hi I enjoyed your article and I know it’s a couple of years old, but I think I have a full blue Merle Chihuahua. She was born from 2 dogs that looked “normal” so I guess one or both must have been ghost merles. But her brother was a brown color, but she is blue Merle. I am going to try to send a pic to see if this is what you mean when you say full blue Merle. She has no brown at all. Her tummy is the same color except when the hair gets thin and her pink tummy comes through like my other Chihuahua that is just a fawn color.
I can’t send the pic, but she’s all mixed with black, white and grey. It gives her a blue look. She has no other colors mixed in. Not brown at all. I’ve never seen another dog like her. Most of them have brown or a little fawn color. She has no other color besides the white and black color which makes her look blue. I was just wondering how rare she is. I never bred her because I heard they can have health problems bad I didn’t want her to have to go thru anything bad either. I was just curious. Thank you again!!
She does sound like a full blue merle.
I have a merle chocolate color Chihuahua. And seem to have lots of skin problems with him and ear problems. Any advice for me merle owners.
I have one of these Chihuahuas and I love them to death just so cuddly and beautiful one blue eye one brown eye and in the blue eye he’s got a streak it looks like a lightning streak in the one side of his blue eye
He sounds gorgeous Sue!
I may be getting a Blue-eyed merle Chihuahua puppy not 100% sure but she has spots like a leopard and blue eyes should I worry about this type of puppy does anybody else have one and can answer some questions about them thank you
Those Kennel clubs are lucky I don’t own a Merle Chihuahua because if it was a purebred and they refused to register it on the grounds of coat color I would find myself a lawyer and sue their butts off.
By purebred, I mean if it came from a litter from a line of purebred Chihuahuas that was traceable for 5+ generations back that they were Chihuahuas especially IF 1 or more of those ancestors had at any time been registered even if the registration had been revoked posthumously).
In such an unjust discrimination I would have the lawyer ask for 10+ million in damages and pain and suffering hoping to at least make them end up paying a million for the unjustness of banning my dog’s registration on the basis of color.
Only in dog breeding can anyone get away with discrimination on the basis of color. Despicable. If a company said no blacks allowed everyone would be up in arms about it but ban a Chihuahua with the equivalent of black genetics and no one says boo because it’s just a dog.
So again, I say they are lucky I don’t have a Merle Chihuahua and that they didn’t ban it’s registration because if I did and they did that I’d sue their butts off for discrimination (presuming purebred litter ancestors for 5 or more generations back in time where 1 or more ancestors were registered at any point in time by the kennel club).
Mark this as well, if I ever do have a Merle Chihuahua and they ban it I will do exactly that, sue them over the ban.
Yeah it does seem like discrimination.
I may be getting a Merle chihuahua. I already have a Yorkie/rat terrier mix. She’s 2. I wonder if they will get along?
They will probably be okay though it may take a week or two. We have an article that may help you here: https://ilovemychi.com/how-to-introduce-a-new-pet-to-your-chihuahua/
Absolutely love my Merle, he has got the funniest, silliest personality.
I bet he’s adorable too Debbie!
Hello i can help i had a rare chi blue merle who lived 2 weeks shy of 20 yrs …yes 20 yrs so definitely not around for just 15 lol he was amazing his teeth were his cause of death
Am looking to get him into the book of records!
Hi, I have a Blue Merle, she is 4 months old, and her name is Bella. I think she makes honor to her name!!!
She is the most adorable pet I have ever.
I just read this articles, and they are very interesting, and informatives, thanks for all information
I would like to send you a picture of here
Hi Nelson,
You can email your photo to cathy@ilovemychi.com and let me know if you would like for her to be in the newsletter or on the Facebook page.
We just adopted a 7-year old female Blue Merle Chihuahua. Didn’t realize there was a Blue Merle type dog. She has the black coat and one blue eye. She’s precious as can be. Still haven’t named her yet. Can’t seem to come up with the right name. We adopted her December 15, 2023, so wanted to come up with a Holiday name. Any suggestions?
Your article has been very informative. Thank you.
Congratulations on your new baby. I bet she’s gorgeous!
Some suggestions for holiday names:
Noelle
Holly
Merry
Belle
Carol
Angel
Joy
Candy
Celeste
Gabrielle
Angelina
Star
Grace
I have a Merle chihuahua with one blue eye and one brown. Does anyone else have this in their best friend?
Yes, I have seen photos where the chihuahua (and other dogs) have 2 different colored eyes. I think it looks really cool.
I have a two year old female chocolate Merle called Hope she is such a cutie but very stubborn sometimes. Loves attention from people and is feisty but very loving also. I would have more if I had the room
The stubborn thing most Chihuahuas have. I’d love to have a merle. They are so pretty!
Hi I’ve got a soon to be 2 year old male black tweed Merle his name is Ash
I haven’t heard of a tweed merle before. How is that different from a regular merle?
Hi I’m Kristy and i have a 4 month old merle female names tiki. We live in Pueblo Colorado. I got her only one month ago and she is very skinny. At first i thought something was wrong but the vet said she was fine just skinny. Recommend giving her baby food. She will not eat dog food since i got her so i have to feed her real food. She play fine and is healthy otherwise. But after looking at pictures of other merle pups I’m wondering if she’s normal and a lot of them are skinny long legs? Of anyone has an answer please let me know . I will post a pic of her alos
You can’t post a photo on here. You can mail it to me at cathy@ilovemychi.com and just remind me about it so I won’t forget your question.
I actually don’t know how to post a pic or if u can
Hi, I have just had my second litter of Lavender merle puppy’s. Neither mom or dad are their color pattern. They are a unique light grey lavender with black spots. I will post a pic, soon as their eyes open within 2 weeks… But, they are gorgeous and I can’t see anyone saying they aren’t chis! Mom and dad are certified registered chis and their offspring are not questionable chis! Period!
I have strolled through hundreds of pictures of Merle, chihuahuas online, and I’m not just saying this, because he is my moral Chihuahua, but I have not seen a single Merrill Chihuahua. Yeah, it comes anywhere close to being as beautiful, cute. Happy unique there’s my little Nugget.
Please let me know if im being bias or do you agree?
Nugget is nearly two and a half years old, and unlike any towa, I have ever known. I like to joke around and call him the unchawawa chihuahua. If dogs can truly get ADHD nugget takes home first place. He has a natural curiosity and love for almost everything he encounters in his world and makes it impossible to be in a bad mood around him.
He does sound like a verys special little guy!