A human has one of the most deadly mouths there is. We have very nasty bacterium in our mouths, which are part of our immune system. This is one reason we are supposed to chew our food well, because the saliva carries these "germs" which kill other germs with are potentially dangerous to us. Yes and no about a dog's mouth being cleaner. They are different germs for the most part than what we carry, and germs a dog carry are unlikely to effect a human badly, whereas the germs we carry often can effect you badly. So it depends on how you view "cleanliness".. A lack of nasty sounding stuff... Or lack of dangerous germs. A bite from a human is one of the most dangerous there is, and you can get blood poisoning very easy that way. I was curious enough about it that I asked my doctor, and he said that part was true.
That being said, our hands are dirtier and deadlier yet. You are more likely to get a disease by shaking hands with a person, than you would be if you kissed that person.
That being said, our hands are dirtier and deadlier yet. You are more likely to get a disease by shaking hands with a person, than you would be if you kissed that person.