Many dogs have brown eyes (or golden- or amber-colored eyes, which are a variation of brown). Some dogs have blue eyes, and some dogs even have two different-colored eyes, sometimes referred to as “odd eyes.” This hauntingly beautiful phenomenon, called heterochromia, can also occur in cats and even people. Let’s learn more about dogs with different-colored eyes or heterochromia in dogs.
Heterochromia in dogs is common in breeds like Australian Cattle Dogs, Australian Shepherds, Border Collies, Chihuahuas, Dachshunds, Dalmatians, Great Danes (harlequin coat pattern), Shetland Sheepdogs, Siberian Huskies and Shih Tzus.
“Coat color and pattern can also have an influence on heterochromia,” explains Doug Payne, DVM, medical director of VCA East Penn Animal Hospital in Pen Argyl, Pennsylvania. “Merle, dapple, white, and increased white patterns around the head all appear to be more prevalent. Interestingly, in Dalmatians there appear to be more females affected than males.”
The iris is the colored part of a dog’s eye. “The color of the iris is determined by the presence of pigment, also known as melanin,” Dr. Payne says. “The iris in most dogs and cats has high amounts of melanocytes that give it the normal dark to golden-brown color. Pets with blue eyes have a genetic mutation in the genes that is responsible for regulating the concentration and distribution of melanin. This results in the absence of melanocytes in the iris, giving them blue eyes.”
Heterochromia in dogs may be hereditary (the dog was born that way) or acquired (the dog’s eyes change color over time).
There are three variations of hereditary heterochromia in dogs:
Complete heterochromia in dogs is frequently seen in Australian Cattle Dogs, Australian Shepherds, Dalmatians and Siberian Huskies. According to Dr. Payne, sectoral and central heterochromia (called heterochromia iridis) seems like an overall more common presentation in dogs. These types are frequently seen in Border Collies, Catahoula Leopard Dogs, Chihuahuas, Dachshunds, Dalmatians, Great Danes (harlequin coat pattern), Shetland Sheepdogs, Siberian Huskies and Shih Tzus.
With acquired heterochromia, a loss of pigmentation within the iris occurs because of some other cause. “This can be attributed to many factors, such as inflammatory conditions, physical injuries and even certain medications,” Dr. Payne explains. “There are many other conditions that may affect eye color in dogs and cats. Some of these conditions can be very uncomfortable for pets and if left unaddressed could lead to permanent damage or even loss of vision.”
If you notice a change in the color of your dog’s eyes or if your dog’s eyes seem painful or uncomfortable, bring your dog to the veterinarian for an eye exam. “Other conditions that can cause color changes in the eyes that are not associated with heterochromia can include cataracts, glaucoma, corneal dystrophy, uveitis, nuclear sclerosis, underdeveloped optic nerve and retinal dysplasia,” Dr. Payne says.
According to Dr. Payne, contrary to myth, dogs with blue eyes usually don’t have any vision problems or impairments and most of them have normal hearing. “There can be rare exceptions to this, as in the case of Dalmatians with partial or sectoral heterochromia,” he says. “These dogs can have a higher incidence of complete or partial deafness.”
Tell us: Do you have any dogs with different-colored eyes? What breeds or mix of breeds are they?
Thumbnail: Photography ©EmilySkeels | iStock / Getty Images Plus.