White paws, often called socks, are an endearing color marking in our pets.  Socks are often seen in cats, but can also be found in dogs and other animals like horses and guinea pigs.

Where do socks come from?  According to a recent article in Popular Science, which outlines some new scientific research on the genetics of coat color, white socks are a form of piebaldism (a genetic mutation that causes white patches of skin and hair).

Before birth, the cells that give color to a kitten’s eyes, skin, and hair (called melanocytes) are concentrated along the back.  During development, these pigment cells move to other areas of the body.

Sometimes the distribution is even, giving the cat a solid color.  But sometimes the color is spread unevenly, leaving white socks on the feet.  Many cats with white feet also have other white areas, such as the chest, belly, and part of the face.  Tuxedo cats are a good example of this.

Interested in learning more about the genetics of coat color in dogs and cats?  Check out this guide to coat colors and patterns in cats…and this one for dogs!