My 9 week old puppy of course is teething and nipping when playing. But I get nervous when he's playing with other dogs and is jumping and play nipping at them. The other dogs will start to growl etc... What do I do? Should I pick him up and stop him or let the other dog tell him no. (The dogs I know, I want my puppy to play with are good dogs, but some I don't know at all if we are in public)I'm afraid he'll play nip 1 to many times to the wrong dog and get hurt!

Yes, you do want to be careful out in public. At 9 weeks, I would keep my puppy away from any dog that you don't know that it is up to date on shots. Even the best shot program leaves a window where your puppy is vulnerable to parvo and other life threatening diseases. See Canine Parvovirus, What you should know about

Many dogs past about 3 years old want nothing to do with puppies and their sharp little teeth. Many owners don't want their dogs to to do play fighting. Treat the older dog like the sofa cushion or other things the puppy shouldn't chew. As soon as the puppy focuses on the older dog, give it a sharp ''Ah, ah, ah!'' and offer it a chew toy. In a couple of weeks, we will be getting the fifth new puppy since old Aster came to live with us at 10 years old 4 years ago. We support her wanting to be left alone.