Is it true that seven human years are equivalent to one dog year? Can dogs really smell cancer? Here, we debunk some commonly held canine myths. Dog Age Though many believe one human year equals seven dog years, this is a common misconception. When your dog reaches 2 years of age, it will age about five dog years to every human year in smaller to medium-sized breeds, and one human year for every six to seven dog years in larger breeds. Nose Color A dog's nose can actually change color in the winter months due to a condition called snow nose (or winter nose). In winter months, owners of black-nosed dogs may notice their pets' noses turning a pinkish color, which is believed to be caused by an enzyme deficiency. Any sudden changes should be examined by a veterinarian. Dog Doctor The ability of dogs to detect cancer via scent receptors ("their sniffer") is, in fact, a truth. A German research report revealed that dogs are able to find early-stage lung...