Are White Cats More Likely to Be Deaf?
There’s a reason a white cat with beautiful blue eyes might ignore you, and it’s not just because cats are total jerks. That cat might be deaf.
Studies have found [PDF] that white cats (but not albino cats) are more likely to be deaf than the general cat population, especially if they're blue-eyed. According to Cornell University veterinarian James Flanders, “About 80 percent of white cats with two blue eyes will start to show signs of deafness when they are about four days old as the result of cochlear degeneration.” The feline disorder been compared to Scheibe hearing impairment, a human condition that results in the degeneration of the cochlea.
But it’s surprisingly difficult to nail down exact statistics on cat deafness. Many studies have explored the phenomenon, but because of the difficulties of putting together a large-scale survey of cat populations, few provide a good estimate of how prevalent the condition is.
As Louisiana State University professor George Strain explains in a 2007 editorial for The Veterinary Journal, “not all white cats are deaf and not all blue-eyed white cats are deaf, but a great many of them are so-affected” [PDF]. A 1984 review of three studies found that, of 256 mixed-breed white cats, a total of 50 percent were partially or fully deaf. Almost 38 percent were deaf in one ear; 12 percent were deaf in both ears. A full 85 percent of cats with two blue eyes were deaf in at least one ear, and 40 percent of cats with one blue eye were. However, an earlier study had put those estimates at 65 percent for two blue eyes and 39 percent for one blue eye [PDF].
Essentially, an inherited trait that disrupts the normal growth and function of a cat’s cochlear pathways is linked to the gene that codes for white pigmentation, called the W gene [PDF]. However, Strain noted in his editorial that few studies have explored the genetic origins of deafness in white cats. A 1996 study of deaf white cats found they had significantly smaller auditory neurons than colored, hearing cats [PDF].
The link between white coloring and sensory impairment isn’t limited to cats. Blue-eyed Dalmatians are also more likely to be deaf than their brown-eyed compatriots. But because so many blue-eyed, white cats are born deaf, they have been used as an animal model to study congenital deafness (a trait present from birth) in humans. However, lest you get too worried about all the cats who can't enjoy music, there aren't that many white cats with blue eyes, compared to the general feline population. One 1991 study [PDF] estimates that white cats constitute about 5.7 percent of the total feline population, and 15 percent of these white cats have blue eyes.
Now, please enjoy this cat-tastic Dutch music video, which includes a white cat jamming out on a speaker and other adorable kitties playing with a metronome.