Snow nose occurs when a dog’s normally dark nose loses pigment and becomes noticeably lighter in color. A dark dog nose can become brown or pink. Sometimes lighter dog noses may still have a darker stripe across the nose. The outer edges of the nose, however, will remain dark.
Snow nose affects white dogs and lighter colored dogs most often, but other dogs may also lose nose pigment. It occurs most often during winter months, causing some people to theorize that the condition is related to sunlight. Because snow nose often occurs in winter time, it is sometimes called “winter nose.”
If your dog’s nose becomes paler in the winter then it will usually become dark again in the summer months, though as they get older some dogs will keep their lighter colored noses year-round.