Susceptible varieties: Alaska, husky, golden retriever, Labrador.

There are two possible reasons:

1, genetic

It is caused by the lack of sunshine and nutrition.

Take Labrador out for a walk when the weather is fine. Buy some seaweed powder for Labrador, and it will get better. I often take him out to bask in the sun, then feed him seaweed powder, occasionally cook some kelp and chop it up for the dog to eat, and then the dog will recover soon.

Extended data:

Snow nose is a normal phenomenon of nose fading in winter. The formation of snow nose is related to an enzyme in the body, and the enzyme responsible for producing black/liver pigment on the nose is affected by temperature, so some people think that "snow nose" is formed because of lack of sunshine in winter.

These enzymes are very active when the temperature is high, that is to say, dogs with bright noses in winter may gradually turn black or even black again in summer. But in winter, this enzyme becomes inactive, so the color of the nose will gradually fade and the snow nose will become obvious again.

This makes many dog parents extremely confused. Although it won't have any impact on the body, some parents always think that a faded nose is not as good-looking as a black nose.

Baidu Encyclopedia-Labrador (canine mammal, pet)