What is an “odd-eyed cat“, how does such a phenomenon occur, and how can you find one as a pet? Let’s dig into what makes these beautiful felines so unique!
Feline heterochromia iridum is the official latin name for the phenomenon in which a cat has more than one eye color. Hetero = multiple, chromia=color, and iridum=of the eye. This is what occurs in an odd-eyed cat!
Types of odd-eyed cats
The condition is called complete heterochromia when each eye is a different, single color, such as when a cat has one blue eye and one yellow eye. Partial or sectoral heterochromia is when one eye has more than one color in it. For example, a green eye may have splotches of brown scattered throughout. Sometimes the eye has one color in the center and another on the outside edge of the eye (also called central heterochromia). Sometimes the eye color is splotched throughout the iris with no pattern.
Eye pigmentation is determined by the distribution of melanin, which also determines the color of the cat’s nose, paws, and fur. Odd-eyed cats frequently have white or predominantly white fur, and one blue eye, since a gene that controls fur color is also connected to a tendency to have differently color eyes (there are multiple genes that contribute to fur color).
Genetics behind odd-eyed cats
Feline heterochromia can be inherited, meaning certain genes were pass from parent to kitten to code for differently colored eyes. It can also result from a congenital condition such as chimerism, in which two zygotes fused together to form one kitten instead of two. Due to the extra genetic material, each eye may have a different color.
Alternatively, a genetic process known as mosaicism can result in a single-zygote having cells with multiple genetic makeups, which could also result in an animal having two differently colored eyes. The genetics behind feline eye color are complicated but fascinating! For a deep-dive on feline genetics that affect breeding, health, and other topics, check out this resource on cat genetics.
All kittens are born with blue eyes. Their eyes change to their final color over the first few months of life. If a kitten is to grow up with one blue eye and one eye of another color, the blues will be slightly different. The kitten’s non-blue eye will change slowly to the other color and the blue eye will remain blue. If an older cat has an eye that changes to a different color, this is not due to heterochromia. Rather, this is likely indicative of a medical condition and a veterinarian should be consulted.
How to find an odd-eyed cat?
Cats with two differently colored eyes are prized by many cat lovers due to their uniqueness! Consult your local shelter to see if they have any odd-eyed cats. Let them know you are interested in adopting if one arrives! Considering fostering kittens, and see if any white kittens you foster turn out to have differently colored eyes. Certain breeds of cat have a high incidence of having two differently colored eyes, such as the Turkish Angora. Thus, you may want to look for breeders near you who might have one available for adoption. Since they are so loved, though, it will likely be expensive. Fostering and adoption is a great way to get exposure to many different kitties, and perhaps find your one true love in the form of an odd-eyed cat!
Scroll down for a small gallery of stunning odd-eyed cats. Share in the comments if you love them, if you think they’re strange, or if you have any questions about cats with differently colored eyes!