My puppy, Koli, is wonderful, he does fantastic on leash walks and is very responsive to commands - aside from the whole "landshark" thing I only have one problem. When we take our puppy and son (2 1/2 year old) to the park or on a walk, Koli FREAKS out when our son isn't nearby. He must be near our son at all times, and as soon as our son walks out of leash range Koli will begin barking, yelping, crying until he comes back. He never reacts if somebody else visits or holds our son, so I don't exactly think he's being "possessive" of him? And he isn't up in my son's face or anything, he'll just lay down and chew or play with us as long as we're CLOSE to the kiddo. I don't mind our pup being closely bonded with our son, of course - they'll grow up to be best friends. But I need to know whether this is considered normal since I've read that these dogs don't become little "guardians" until they're older. I'd hate for this to be something fear-related that can turn into aggression later. Keep in mind this only happens outside the house, never inside - they can be separated by crate or rooms (or our son could be at somebody else's house) and Koli is totally fine.
Advice would be very much appreciated!! I am planning on working with pup for the next couple weeks (however long it takes) at the park and gradually having him separated from our son farther and farther, with lots of treats and training, in hopes that he won't become too possessive of our son later on - but if anybody has other suggestions, or has dealt with something similar, PLEASE do share!!