If your dog's dark lips start turning pink, don't panic. It's possible he inherited a condition called vitiligo, which turns black pigment in skin pink as the dog ages. There's no treatment for vitiligo, but not to worry it's only cosmetic and doesn't harm the dog. However, it's always a good idea to have your vet examine your dog if he develops any change in skin color. There's always the possibility that an allergic reaction or some other disorder caused the discoloration.
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Vitiligo in Dogs
While dogs inherit vitiligo, it's not apparent in puppies. The darker skin starts losing color when the animal reaches adulthood. In addition to the lips, an affected dog might lose color on his coat and nails. Generally, hair color changes in the area of the eyes or muzzle. Sometimes, the color changes back to the original dark shade, only to fade again.
Affected breeds include the dachshund, Doberman pinscher, golden retriever, Belgian Tervuren, Irish setter, Old English sheepdog, Rottweiler, Australian shepherd, Shetland sheepdog, Samoyed, Saint Bernard and Siberian husky.