Tracey-LOL, Eden and one of our puppies do that too- in fact Eden now opens her mouth when Gazzy comes towards her, and she is fast learning to keep a close eye on her arrowroot or it becomes puppy property...
Satya- ive heard that too- dogs have far less germs in their mouths than us....
But its not silly to question these things, knowing everything that pops up as a first time mummy, or 2nd/3rd etc is impossible... plus you are just looking out for your bub.
xoox