To answer this question, first you must answer my question. Why do Dogs lick their private parts? If you said to clean themselves... you are totally mistaken and must leave now! For the rest of you, I will detail it. Dog's lick their private parts to relieve the searing, blinding, fiery pain of Dog Flu. You see, Dog Flu attaches itself to the sexual organs, causing severe pain and swelling. The only way to relieve this pain is by licking one's private parts almost constantly.