A dog that loses its sense of smell may show symptoms such as loss of appetite and long-term dryness of the nose, which are generally not very obvious, so it is best to take the dog to the pet hospital for examination. Generally, a dog's nose may malfunction due to pungent smells, exposure to the sun or other circumstances. If the dog does not lick its nose frequently and the nose is dry for a long time, it means that the dog's sense of smell may be problematic.