Why Do Some Dogs Have Different Colored Eyes?

Color Eyes

Have you ever seen dogs with two different colored eyes? Stunning! But why does this happen? Find out everything you ever wanted to know about heterochromia.


The next time you come across a dog with two different colored eyes, don't stop to clean your glasses or rub your eyes. You're not seeing things — you've simply found a dog with heterochromia. The term originates from the Greek word heteros, meaning "different," and chroma, meaning "color."


How Does This Happen?

A dog's eye color is determined by the amount of melanin found in the iris. Brown eyes indicate a high concentration of melanin, while green or blue eyes indicate a lower amount. Dogs with two different colored eyes have differing melanin levels in each eye. Heterochromia, however, can also be centralized. That is, the iris of one eye can be two different colors.


If a puppy had two different colored eyes when he was born, then the heterochromia is a genetic condition passed along from his mother and father. 


A dog can develop heterochromia later in life, though, resulting from an injury to the eyes, or from a condition like glaucoma, cataracts, an underdeveloped optic nerve, or retinal dysplasia. If this is the case, be sure to inform your dog's veterinarian in order to check for any underlying diseases or issues developing in your dog's eyes. Blue eyes, for example, whether it's one eye or both, can be a sign of deafness in Dalmatians.


More Common for Certain Breeds

Some breeds of dog are more disposed to have heterochromia. Among these are Siberian huskies, American foxhounds, and Australian Shepherds. In addition to dogs, cats and horses are also susceptible to heterochromia. And, to a lesser extent, the condition also occurs in humans. Ever heard of David Bowie?


Like humans, every dog is unique in appearance and personality. Dogs with two different colored eyes certainly fit that mold. So if your dog has heterochromia, chalk it up to just another thing that makes your pet special. And know your pooch is not alone.