Did you know that only about 8 to 10% of the human population has blue eyes? Dogs can also have blue eyes, though it's rare as well. But why do some dogs have blue eyes? And are certain breeds more likely to have them? Find out the causes of blue eyes in dogs and discover 28 dog breeds with blue eyes, here.
What Causes Blue Eyes?
Blue eyes actually don't contain any blue pigment; instead, they are caused by a lack of melanin. When light enters eyes without pigment, particles in the stroma layer of the cornea reflect blue wavelengths. This is similar to why a clear sky appears blue.
Pro Tip: Some dogs have only one blue eye or their eyes are partially blue, a condition known as heterochromia.
What Causes Blue Eyes In Dogs?
There are a few factors that contribute to blue eyes in dogs. The most common cause is genetic, as with most physical traits on an animal's body. That being said, there are also a few non-genetic causes.
Genetic Causes Of Blue Eyes In Dogs
1. The Genetic Blue Eye Variant
DNA influences eye color, as it does with other physical traits, and some dogs have the gene for blue eyes. This variant is known as the ALX4 gene and is quite rare. In fact, only around 5% of dogs have the blue eye variant, according to Wisdom Panel. Dog breeds that most often have the blue eye variant include Siberian Huskies (who are more likely than others to carry the ALX4 gene), Alaskan Klee Kais, Miniature American Shepherds, Australian Shepherds, as well as mixed breeds.
2. The Piebald Variant
Another genetic influence that can cause blue eyes is the piebald coat coloring, or white spotting. This occurs when a variant of the most common known genetic cause of piebald (MITF) results in a lack of pigment in the coat. It can present as white spots of fur, partial or fully pink noses, pink eye rims, and blue eyes. Common breeds seen with blue eyes from the piebald variant include American Staffordshire Terriers, Dalmatians, Bull Terriers, and Boxers.
Pro Tip: Pigment is extremely important for the development of sight and hearing in puppies. This is why dogs often have color around the eyes and ears, even if they're white everywhere else. However, those that do have blue eyes from the piebald variant typically carry two copies of the piebald gene, which makes them much more likely to be deaf in one or both ears.
2. The Merle Variant
Blue eyes in dogs are also not uncommon in dogs with genetic variants that cause merle coats. Merle, also known as dapple, in dogs is a coat pattern that presents as irregular patches of darker fur on top of lighter fur of the same pigment. For instance, black on gray (blue merle) and brown on tan (red merle). Research has shown that merle in dogs is caused by the same gene in every breed that exhibits it. This suggests that it comes from an ancient mutation that existed before breeds and breeds groups were created, as it's highly unlikely to arise independently in each breed. There are many breeds that carry the merle variant, including Australian Shepherds, Border Collies, Cardigan Welsh Corgis, Catahoula Leopard Dogs, Great Danes, Shetland Sheepdogs, and more.
Like the piebald variant, dogs with two copies of the merle genes can experience health issues. These dogs are often totally white, deaf, blind, and have eye abnormalities (like unusually small eyes or abnormal irises). As such, it's considered inhumane to breed two merle carriers.
Non-Genetic Causes Of Blue Eyes In Dogs
Albinism is a condition that affects the production of melanin, the pigment responsible for providing color to the skin, hair, and eyes. Albinism in dogs is quite rare (with less than 1% of dogs tested on Wisdom Panel showing it), but those that are albino often have blue eyes (some have green), as well as pink noses and skin around the eyes. Additionally, albinism can come with health issues such as eyes that are smaller than normal, increased sensitivity to light, lens or iris deformities, impaired vision and poor eyesight, or complete blindness.
Pro Tip: Albino dogs are very sensitive to sunlight and are more prone to sunburn, so it's important to take extra precautions during sunny months. This includes using dog sunscreen, UV-Protective Clothing and other summer essentials.
5. Other Health Conditions
Some eye conditions in dogs can cause changes to their eyes, including the color. But they typically change to a cloudy gray-blue and don't look the same as the genetic blue eyes. Conditions that can cause color changes in eyes include cataracts, glaucoma, corneal dystrophy, anterior uveitis, nuclear sclerosis, and interstitial keratitis. These often occur later in life as adult and senior dogs due to age, injury, or disease.
Pro Tip: These conditions can reduce eyesight or even lead to blindness, so take your dog to the vet if you notice changes in their eye color.
All puppies are born with blue or bluish eyes and tend to stay that way from the time they first open them to around 16 weeks. At that point, their eyes typically change to their permanent color (which is usually brown or amber).
Do Dogs With Blue Eyes Have More Health Issues?
As mentioned above, pigment is critical for the development of sight and hearing in dogs. This is why dogs often have color around the eyes and ears, even if they're white everywhere else. However, dogs with blue eyes, outside of those with the blue eye gene, can be more prone to health issues, particularly with their sight or hearing. They are at a greater risk of:
Cochleosaccular deafness, which is a hereditary condition related to pigment in the coat and eyes. This is more likely to be seen in white dogs with blue eyes and shows up within one to three weeks of age in one or both ears.
Merle ocular dysgenesis, which are eye abnormalities that arise in puppies from breeding two merle-coated dogs. It can cause impaired vision and poor eyesight, abnormally small eyes, increased sensitivity to light, a higher risk of cataract development, and more.
Eye abnormalities - such as eyes that are smaller than normal, increased sensitivity to light, lens or iris deformities, impaired vision and poor eyesight, or complete blindness - can occur with Albinism and unethical breeding (e.g. two merle variants).
Pro Tip: Some research from Louisiana State University concluded that "Blue eyes, resulting from an absence of pigment in the iris, are common with pigment-associated deafness, but are not, in and of itself, an indication of deafness or the presence of the deafness gene." However, when dogs of certain breeds do have blue eyes, they are statistically more likely to be deaf. These breeds include Dalmatians, English Cocker Spaniels, Bull Terriers, and English Setters. The most clear indicator of deafness in dogs is being positive for the deafness gene.
Dog Breeds With Blue Eyes
Alaskan Klee Kai
American Staffordshire Terrier
Australian Cattle Dog
Cardigan Welsh Corgi
Catahoula Leopard Dog
Miniature American Shepherd
Mixed Breed Dogs (e.g. Aussie Doodle, Husakdor, Pomsky, Shepsky)
Old English Sheepdog
Pembroke Welsh Corgi
Pit Bull Terrier