Dear AKC: My two-year-old yellow Labrador Retriever usually has a black nose but this winter it turned a very light pink. His nose is not dry, but looks like someone drained the color out of it. What causes this? Is there anything I can do to fix it? -- In the Pink
Dear Pink: Whenever your dog's nose becomes something other than the cold wet nose they are famous for, take note and decide whether a trip to the vet is called for. A dog's nose that becomes dry and cracked or changes color is cause for further investigation. It may be a symptom of some more serious problem.
Most likely, what your dog is experiencing is something called "winter nose" or "snow nose" and it affects many breeds, including Labradors, some northern breeds and even smaller dogs like terriers. A normally black nose will fade during the colder, shorter daylight hours of winter. The dark pigment will return when the days are longer and the weather warms up. Dogs are known to repeat this process year after year.
There is no definitive answer for why this happens, but several observations have been made and a few theories bandied about. One notable observation is that this condition happens to dogs in warmer climates, so the cold temperature most likely isn't as big a factor in triggering it. Perhaps the length of daylight associated with colder weather plays a part. And some researchers and breeders believe there may be a genetic component to this condition. The temporary loss of pigment is not anything that is harmful to the dog and there is no "cure" or fix for it, short of coloring it with make-up, which I don't recommend. But you can check to see if your dog has a permanent loss of color to his nose.
The term "Dudley Nose" can refer to a yellow Labrador with chocolate pigmentation. A Lab with absolutely no pigmentation on the nose or eye rims, where all areas are pink in color, is very rare and most likely a genetic quirk.
To tell the difference between a simply faded nose and a "Dudley" check the eye rims and gum tissue color. A Dudley will have only light pink or tan skin while the other dogs will have black pigment in these areas. In some dogs this permanent lack of pigment in nose and eye rims is a disqualification for the show ring, while winter nose is not. The pink nose has also been nicknamed a "Liver Nose" in some breeds, and is acceptable in some liver-colored breeds but not in others. "Liver Nose" has been linked to a chromosome, which gives credence to the possible genetic origin of winter or snow nose. While winter or snow nose is not harmful in any way, sun-block should be applied when dogs are outside for a long time to avoid sunburn to the sensitive pink skin.