Have you ever seen a dog with two different colored eyes? The scientific term for this phenomenon is heterochromia. Our family dog actually has one of the three types of heterochromia. Though it seems like it would be rare and unique, this condition is more common than you may think. Why are there dogs with different colored eyes? What is heterochromia in dogs? Read on to find out and 15 breeds with dog heterochromia.
Causes of Heterochromia in Dogs
Heterochromia can affect dogs, cats, horses and even people. It's caused by an absence of the pigment melanin in all or part of the eye, resulting in a blue or bluish-white color. The color of a dog's eye is determined by melanin, with most having high amounts of melanocytes (which is why many dogs have golden to dark brown eyes).
Usually, heterochromia is a genetic condition or hereditary, inherited from a relative. But it can also occur later in life from an issue with or related to the eye, such as injuries, health issues, inflammatory conditions and certain medications. This is referred to as acquired heterochromia. While hereditary heterochromia is often nothing to worry about, any changes in eye color are potential cause for concern. So consult your vet if you noticed your dog's eye color has changed.
The color and pattern of a dog's coat also has an influence on heterochromia. It's more common among dogs with fur - particularly around the head - that is merle, white or dappled (lighter areas mixed with darker areas of color, sometimes showing as spots or splotches). In addition, female Dalmatians are more affected than males, interestingly.
Types of Heterochromia
There are three types of heterochromia:
- Heterochromia iridis (one eye is a completely different color from the other, also known as complete heterochromia)
- Sectoral heterochromia (iris is partially blue or bluish-white)
- Central heterochromia: (blue color spreads out from the pupil, mixing with other colors in a spiked or halo pattern)
Does Heterochromia Come With Health Issues?
It's a common misconception that heterochromia means a dog's vision or hearing is impaired. The only breed that may have a higher incidence of blindness or deafness with heterochromia are Dalmatians. That being said, acquired heterochromia can be caused by an eye injury or health issue and, because of that, may have health implications. Health conditions that can cause changes to the color of your dog's eye include cataracts, glaucoma, retinal dysplasia, corneal dystrophy, nuclear sclerosis, uveitis, and underdeveloped optic nerves.
Most Common Dog Breeds With Heterochromia
Heterochromia is most common among the following 15 breeds. Heterochromia iridis is more frequently observed in Huskies, Dalmatians, Australian Shepherds, and Australian Cattle Dogs. While the other two types of heterochromia are more common in general and more often seen in the remaining breeds.