Dogs licking a person in the face and primarily on the lips

Question
Dogs licking a person in the face and primarily on the lips.

My children see no problem at all with allowing our family dog to lick them in the face and will not stop our dog from doing that. My argument to that is that you shouldn't even let a human lick you in the face much less a dog. Thier argument and my question is, isn't it a urban rumor that a dogs mouth is cleaner than a humans? I can not see how this could be possible as dogs will eat some pretty nasty things as cat poop seems to be a delicacy to them among other nasty things. And then they ge straight from eating things like that or licking their own private areas to licking my kids in the face. I've never heard of any tranmittable disease from a dog to a human but I would think things like diarrhea could be caused from allowing a dog to do this.
Please let me know if my concerns are correct in allowing a dog to freely lick them in the face. Also to solve whether it is a urban rumor or not please let me know if a dogs mouth is in fact cleaner than a humans.
Thank you for your time to review and answer my question.
Brian

Answer
I am in agreement with you in that I do not like a "licky dog", Brian. However, face-licking is something that some dogs do more than others, and it is a completely natural thing for them to do. 99% of the time, when a dog licks you on the chin or mouth, it is showing submission to you (there is that 1% that actually does it in a dominant fashion, but I won't go into that right now). The urban myth about a dog's mouth being clean is not an excuse for letting a dog lick you in the face, for the very reasons that you gave. It is my understanding that the myth originated because people discovered that if a human were bitten by another human, this would be more dangerous than if the human were bitten by a dog. That is because the wounds would have a larger chance of getting infected, since the biting human has human germs, while a biting dog has dog germs (less harmful to humans). Another possibility is that when a dog is injured, he licks the wound until it is better, so people assumed that a dog's saliva was somehow 'clean.'

If you do not want the dog to lick people in the face, there are a few things you can do (but EVERYONE that comes in contact with the dog must follow the rules as well - if one person allows licking and one does not, you'll never get the dog trained). First off, since this is a natural behavior, do not punish or correct the dog for licking. Instead, if the dog starts to lick, simply tell him "No lick" and stand up and walk away. Do not look at him, talk to him, or acknowledge his presence for at least a minute or two. He will learn that licking causes you go go away and ignore him and will soon stop the behavior. If this doesn't work, or you need anything else, please don't hesitate to let me know!

Kristen