Cats With Different Eye Color: Photo And Scientific Explanation Of A Beautiful Phenomenon
A cat with eyes of different colours looks mesmerizing. Who would refuse such a pet, which arouses persistent interest and admiration among guests and friends! People even start looking for a breed of cats with different eyes, not understanding the reason for this unusual phenomenon.
I am in a hurry to disappoint — such a breed does not exist. The good news is that kittens with different eyes are found in any cat breed, for which we assume a solid white or turtle color.
I walked with my friend when we saw an adorable cat sitting on the street. We couldn’t take our eyes off this animal, so my friend decided to go and talk to his owner. After some time, he came back with an excited smile.
“She said that she found him in her front yard only two days ago!” He exclaimed happily. “But what’s even more amazing is that he has different-colored eyes.”
We were both intrigued by this story and immediately agreed to adopt the little kitten as soon as possible!
How does it turn out that cats with different eyes colour?
Different eye colour has a scientific name — heterochromia. Heterochromia is found in cats and dogs, horses, and even humans (although sporadic).
Complete heterochromia — is when each eye is colored in its own color, and partial heterochromia — when two colors are combined in the eye’s iris. Partial heterochromia is really rare, but you will not surprise anyone with entirely different eyes in a cat.
At full heterochromia, one eye will always be blue, and the other will still be any color: yellow, green, orange. The secret is that cats’ blue eyes are not the color at all, but their absence. In other words, the color is genetic, but something has prevented the pigment from migrating to the iris.
The pigment is distributed at the moment when the kitten is still in the mother’s womb. It is impossible to influence this process, and so is the prediction. Therefore, breeding a “breed of cats with different eyes” is simply impossible.
Why does disagreement occur regularly in specific breeds or breeding lines? The white color is to blame for everything! The white color gene (W — white) doesn’t carry information about the color, but suppresses all other colors. A snowy white cat may well give birth to colored kittens if it is secretly not white, but red or black. This white gene also violates the pigment in one eye — or both, as it turns out. In other words, some kittens will have green or yellow eyes, some will have blue eyes, and some will have different eyes.
When the new family moved into the neighborhood, I had to show them all around. They were just so incredibly interesting! Not only did they have a white cat, but their dog was also white. She’s such a cute little thing, and she likes attention too.
Anyway, we go back to their house and meet the cat who is so friendly, and you can tell that he loves people — not like some standoffish cats. And of course, we went inside and saw this beautiful green mink rug with matching pillows on the couch! It was supper time when we left there because it seemed like they wanted privacy for dinner.
I guess different breeds or breeds generally disagree more than others do about things sometimes too! Oh, I almost forgot to tell you about the name of their cat! You’ll never guess. It’s Mittens! Isn’t that the cutest thing ever?
When the new family moved into the neighborhood, I had to show them all around. They were just so incredibly interesting! Not only did they have a white cat, but their dog was also white. She’s such a cute little thing, and she likes attention too. Anyway, we go back to their house and meet the cat who is so friendly, and you can tell that he loves people — not like some cats which are standoffish. And of course, we went inside and saw this beautiful green mink rug with matching pillows on the couch! It was supper time when we left there because it seemed like they wanted privacy for dinner. I guess different breeds or breeds generally disagree more than others do about things sometimes too! Oh, I almost forgot to tell you about the name of their cat! You’ll never guess.
Does it affect the health of the kitten?
Eye color does not affect the cat’s vision. But if different eyes appeared under the dominant white gene’s influence, the cat may have hearing problems. The fact is that W-gene inhibits the migration of melanoblasts cells to the iris and the inner ear, disrupting this organ’s development.
That is why white cats sometimes suffer from congenital deafness. The problem often concerns blue-eyed animals (the gene’s action is manifested as much as possible).
Still, contrary to the general misconception, a white cat with colored eyes can also be deaf. If one eye is colored and the second one is blue, the cat may be deaf from the blue eye, and it is customary to hear with the second ear. In this case, the owner will hardly notice any problem. It will be possible to check the cat’s hearing only with special tests under anesthesia in the veterinary clinic.
Deaf cats should be strictly rejected. They are not allowed to breed — this applies to any breed. In addition, two white blue-eyed individuals should not be crossed with each other, even if both cat and cat hear perfectly.
Breeds of cats with different eyes
So, there is no blue-eyed gene, no deafness gene, and no discord gene. Why does the Internet persist in offering some breeds of cats as “discord”? These are the breeds where the snow and white color:
- is the only acceptable color: Kao mani;
- is very common: Turkish Angora;
- is combined with colored spots: Turkish Van.
Different eyes are often found in breeds of cats. White color is the only tolerable variety, not the main feature of the breed. Breeders have a theory that white animals must be crossed with two colors to get kittens with heterochromia.
Such animals are also called pegs: white spots alternate with painted areas. If the white spots are very, the cat may look completely white (a spot of color may be on the tail, on the head). This white color is not caused by the gene W, but the spot is S (spot) by the white peg leg gene. Gene S also disrupts the migration of melanocytes to the wool and sometimes to the eyes, but does not cause deafness. Since the spots are asymmetrical, it is not surprising if one eye is dyed and the other is not.
There is another pattern: if a kitten (or several) with different eyes was born in the litter, these parents would likely get stable kittens with heterochromia in the next litters.
The white color is not caused by the gene W, but the white peg leg gene is S (spot). Gene S also disrupts the migration of melanocytes to the wool and sometimes to the eyes but does not cause deafness. Since this genetic mutation causes a variety of patterns in different colors on cats with spots, some may also have heterochromia! Which pattern has your cat been developing? Let us know to find out if they, too, are part pegs or completely white!
Thus, eyes of different colors can be found in cats of any breed. The standards we assume white or spotted color — Cornish Rex, Sphynx, Maine Coon, Persian cats and exotics, British cats, and many others.
Do not discount the usual pedigree cats — mestizos, who also often have heterochromia. It should be said that a discordant kitten has a dramatically increased chance of finding a home — many are willing to take such an unusual pet, even if it is “noble” blood. Such cats will never bite you 😜
It is believed that cats with different eyes bring good luck to the owner and have strong magical powers. And even if you are far from esoteric, it is impossible to deny that cats with heterochromia look very impressive and mysterious.
One of my acquaintances even found his mongrel cat a “bride” in the hope of getting a discordant kitten. Unfortunately, white Dobby (one eye yellow, the other blue) and white blue-eyed cat had kittens with the same yellow or blue eyes. Two of them were cream color, two were white and both white kittens were deaf.
Interesting observation
There is another reason why a cat may have elegant colors (like a two-faced Venus cat, for example) or eyes of different colors.
Cats are multi-berry animals. Occasionally, two fertilized eggs merge into one instead of quietly attaching to the uterus wall and developing further. It turns out one healthy, viable kitten, but with a double set of chromosomes. This phenomenon is called chimerism.
Embryo fusion — it sounds pretty creepy, but in fact, such animals live quietly, bring offspring, and no one even knows what an unusual creature is sheltered at home. You can’t consider a cat a chimera just based on a strange color, to confirm if you need genetic tests (which no one is in a hurry to perform).
Some kittens were born in human families just for curiosity. For example, in 1998, a kitten was born in the UK who got into the world with two different and well-developed forepaws: one expected and another that looks like a flipper. His owner brought him to the local history museum, but when they saw this miracle of nature, the staff decided to keep him in their collection. I think his paw like a flipper will be helpful for future archeologists: they can dig more efficiently and pleasantly with it :)
Also, cats may have mosaicism — areas of cells with DNA differences resulting from the mutation. Mosaicism is often “blamed” for the appearance of hair areas of “impossible color”, partial eye heterochromia, complete heterochromia in turtle, colored cats. The difference between a mosaic and a chimera is that the mosaic mutations occurred based on their own cells. In contrast, the chimera has two complete and different sets of chromosomes that were not mutable.
It makes sense to suspect such deviations if cats have different eyes, but neither is blue. For example, one is yellow or orange, the other is green. Interestingly, heterochromia variants in completely colored cats are much rarer than in white animals, but still happens!
From what age you can determine the different eye color of a kitten
If before heterochromia was considered a genetic anomaly and did not welcome such kittens’ appearance, now it is just the opposite. Breeders fight over the unraveling of genetic algorithms responsible for eye color in cats, and kittens with heterochromia are welcome and in demand.
But when kittens only open their eyes, they all have the same “baby” blue color.
The accumulation of pigment in the iris occurs gradually, and with age, the color of the eyes changes. It is guaranteed to determine heterochromia at 2.5–3 months.
Experienced cat guides, however, know that you can learn eye color before. For this purpose, kittens are examined in a dark room with a weak light source. Blue eyes burn red and the rest green.
Conclusion
Fixing the different colors of the eyes and passing them on to the offspring is not yet possible. If someone tells you that there is a breed of cat with different eyes, know it’s a myth.
Do not cross pure white animals with different eye colors in the hope of getting an unusual offspring with heterochromia: remember the negative impact of gene W on your hearing.
