[JoeyP]

The real answer is No, a 10 year old should never be doing this to a dog of any age
But grabbing a puppy ... not a dog by the scruff of the neck is a good tool to use at times
depending on how you do it and for what reason
mothers will move a puppy from place to place lifting the puppy by the scruff of the neck
and dominant members of a pack will bite and grab other pack members there too
I grab my puppies there when I have to stop them from doing something Right away ... like chewing on something that can be dangerous or if I need to get something out of their mouths before they swallow it
It does freeze them allowing you to stop an activity right away