Labrador nose pink is purebred?

Labrador nose pink is purebred 1. genetic inheritance. The dog was born with a pink nose, and cannot be changed. 2. the dog is older, resulting in melanin deposition disorder, so the nose and coat color becomes lighter. 3. lack of trace elements or vitamins, will make the dog nose melanin deposition reduced, pay attention to supplement these nutrients, while more dogs out or in the balcony in the sun. 4. the dog’s nose because of the wound broken skin and become pink, to be wound recovery It can become black.