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Dogs with Blue Eyes – The Causes and Dangers

How could you resist those stunning blue eyes? They are rare, beautiful, and sometimes sought out for by new owners. But there's a few different causes and dangers you may need to be aware of.

The default eye color for dogs is brown. Genetics, pigmentation, and health issues can all play a roll in altering the color of their eyes. So we'll look at the most common reasons your pup has blue eyes.

How it Happens

Merle Gene

Does your dog have white patches of fur on their body and face? A nose that is partly or entirely pink? This is actually due to cells unable to create pigment, and can result in bright blue eyes.

Random pigment dilution on the nose, eyes, and fur is caused by the Merle gene, and is more prominent in certain breeds. The more pigment dilution on their fur and skin, the more likely they are to have blue eyes.

Carriers of the Merle Gene:

  • Australian Shepherd
  • Catahoula Leopard Dog
  • Border Collie
  • Old English Sheepdog
  • Hungarian Mudi
  • Cardigan Welsh Corgi
  • Collie
  • Shetland Sheepdog
  • Dachshund
  • Beauceron
  • Bergamasco
  • Great Dane
  • Great Pyrenees

Adopting a merle carrier does not guarantee your dog will have blue eyes, and is still uncommon no matter what breed you adopt. Keep in mind all dogs are born with blue eyes and will begin to change to their permanent adult-color at 10 weeks old.

While blue eyes sounds like a desirable trait to reproduce, the Merle gene can have a dark side when breeding – which is known to cause a number of major health concerns .

When two Merle carriers are bred ​their litter then becomes known as “double merle” and are at a much greater risk of health issues. Sometimes being born deaf, blind, or both. Therefore, breeding two merle gene carriers is strictly forbidden and considered inhumane.

However, litters from a Marle carrier bred with a non-carrier do not exhibit any health issues. Owning and breeding a Merle carrier comes with the extra responsibility of careful mate selection.


Heterochromia literally translates to two different colored eyes. And this condition can occur in humans, horses, cats, and dogs. This can be caused by the Merle gene, loss of pigmentation, or just breed specific genes.

In some cases two different colored eyes can point to health issues such as cataracts or glaucoma.

White patches of Fur on Face

​White patches of fur around the face can also create blue eyes. Their fur is unable to produce pigmentation around those areas, and the eyes, nose, and skin is also affected.

Basically, any breed that has dominant patches of white fur on their face has the potential to create blue eyes.


Breed specific genes

Some breeds have a different set of genes that create blue eyes, most commonly found in Siberian huskies or Bordor Collies. These dogs don’t suffer from the health conditions produced by the Merle Gene, nor do they show pigment loss on their hair or nose.


Albino dogs, also known as C-series, show a massive loss of pigment through their entire body, also resulting in a pink nose and blue eyes. There is no “pure” albino dog on record, but some breeds have shown significant loss of pigment that result in a white coat, pink nose, and blue eyes.

CC Image courtesy of Narisa on Flickr

Recessive Genes

Although it's very rare, blue eyes have been known to show up in any breed, even if their immediate parents show no signs of carrying those characteristics. Most commonly this occurs in a mixed breed where a husky or shepherd was potentially bred into the line. 

However, being a recessive gene, blue eyes can occur with literally any dog.

Puppies with Blue Eyes

All young puppies are born with varying shades of blue eyes. Some appear to be a little more "green-blue" while others will have blue with spots of brown. Within about 10 - 12 weeks your puppies eyes will mature and begin to turn to their new permanent color.

Brown is the default eye color for mature dogs. However, some puppies will keep their blue eyes into adult-hood. Again, this can be due to the Merle gene, breed-specific or recessive genes, or just a loss in pigmentation in the iris.

Health Concerns

​Blindness or Deafness

Blue eyes does not indicate that your dog will eventually go blind, deaf, or have any other genetic defects. Variation in pigmentation in the iris can occur for varying reasons, and doesn't necessarily point to health concerns.

However, if your dog is a Merle Carrier, and is bred with another carrier, their offspring (then called "Double-Merle") have a much higher chance of exhibiting dangerous health problems, such as blindness or deafness. 

​Eye Disease

​​​​If your dog's eyes are suddenly turning blue or cloudy this can indicate your dog has contracted an eye disease such as Cataracts or Glaucoma. In this case you must seek out a Veterinarian, some conditions can cause irreversible blindness. 

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Liam J. Barnes

Liam is a dog trainer, owner, and lover with over 20 years experience. You can find him working with vet clinics, grooming facilities, training centres, and food/toy brands in order to grow their business. His passion for dogs and business make him uniquely suited to help move the world forward with canines and humans.

19 thoughts on “Dogs with Blue Eyes – The Causes and Dangers”

    • There are no silver Labradors. This a result of crossing a Weimeraner and a Lab. Some will advertise a Lab with blue eyes and “Charcoal fur”, again the result of crossing the two breeds above. Do your deep research on the breeder before you buy what may be an animal subject to hisplaysia, blindness, or deafness.

  1. Heey, my brother has a blue eyed pit bull puppie, his eyes are blue & sometimes they turn silver every now & then. A friend of ours told us that he might be blind but the pup seems fine with his vision. Should I tell my brother to take the pup to the vet??

  2. We have a 7 month old, blue eyed Catahoula Cur and noticed he has a black spot at the bottom of each eye. What can you tell us about that? He seems to see well, but didn’t know if that will be a problem as he gets older. I can send a picture if that helps. His face is half white and half tan.

  3. we have just bought a puppy with one blue eye and one brown. she is gorgeous and the breeder assures us that she has no health issues. as we do not want to show her we dont care.

  4. One of our puppies has a grey fur and blue eyes but her siblings fur color are black with brown… but her siblings eye colors are somewhat grey with brown. I checked their parents eye colors and all of them are brown. I was thinking they got this from their grandparents who’re mixed breeds. The puppies are all healthy and their growing is very fast. 2 of the puppies already have their teeth. They are already 4 weeks old. Should we go to the vet to check them?

  5. Is the first picture of a dog laying on the leaves a border collie? I just rescued a puppy that was dumped and we are trying to guess what she is. She looks just like that dog in the face shape, blue eyes and all, with an entirely black coat and her ears are starting to stick up

    • Could be border collie or Australian Shepherd mix. Either way, that set of genes could make an excellent family pet.

    • Hi! I have a 5 month old catahulagreat pyrenees mix and he has a blue eye and a green eye and his blue eye was completely blue up until about a month ago and he now has brown spots in the corner. Should I be concerned ?

  6. I have a double merle Australian Sheperd and he has light blue eyes. My kids left him outside most of the day today and when I brought him in the house this evening I noticed that one of his eyes have turned green. What is going on?!?!


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