About 3 percent of cats are white. However, the question needs to apply to domestic and stray cats outside of the pedigree cat population. This is because cat breeders sometimes selectively breed white cat, which distorts the percentage of all-white, cats in the population. So, taking the non-pedigree cat population, it is said that white cats ‘rarely represent more than 3% of the free-ranging cat population’. This means that about 3 percent (3 cats in 100) of the non-purebred cat population are totally white.
The source of the information is Dr. Bradshaw in his book Cat Sense. It’s a good source. By contrast, he says that black cats are “so common and widespread that it must not bring any major biological disadvantage to the cats that carry it”. He is referring to the genetic mutation which causes the coats to be all-black.
The reason why all-white cats are much rarer than all-black cats is because the dominant white gene (DW) ensures that the cat stands out against a background. Or they are genuine albinos.
Their camouflage is gone and they are less likely to catch food to sustain themselves. The gene brings biological disadvantage. The dominant white gene has a negative impact upon survivability. I would suggest that using Darwin’s theory of evolution, and by natural selection, white cats would eventually fade from the entire domestic cat population but for the fact that they are domesticated and therefore supported by their human caretakers.
White cats are less healthy than black cats. In fact, it is said that black cats are healthier than the general population. Conversely, white cats are often deaf. And of course, the lack of melanin in their hair strands means that the skin of the ear flaps is more exposed to ultraviolet light which can damage it causing cancer.
You will see white cats with ear flaps amputations through damage from sunlight. The fact is that the dominant white gene removes pigment from hair strands. This is not a gene which creates white pigment. It is a lack of pigmentation which is also why white cats have blue eyes or odd-eye colour (one blue and the other gold/yellow). Blue eyes are those with no pigmentation in the iris. The blueness comes from reflection of white light in the eye.
As a postscript, black is commonest in Britain and Ireland, in Utrecht in the Netherlands, in a few American cities such as Denton in Texas and in the city of Chaiang Mai northern Thailand.
Black cats are generally unpopular despite the health advantages of being black while white cats are generally popular especially white Persian cats. This difference emphasises the fact that most people are more concerned about the appearance of the domestic cat rather than their health.
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