JJ wont share.

Question
I have a 9 year old male Jack Russell.  He was very good until we got a new puppy.  He still listens to all my commands but won't play nice with new dog.  He has to take whatever toy the new dog is playing with.  He growls and snipps at her even when she lays submissively.  The new puppy is a female Lab and Boxer mix.  She tries to play with him but all he does is snap at her.  He has never done this with other dogs.  He plays great with every other dog he comes in contact with.  I have put him in a submissive position when he tries to steal a toy from her and then claim the toy for myself for several minutes.  I offer him other toys I know he love but he fixates on what the other dog has.  When laying anywhere and the new pup comes along he immediately growls and snaps at her.  I shoosh him and tell him no but with no affect.  Any advise is appreciated.  He is still our best friend and want to add to his friendship with this new puppy.

Answer
Hi Toni,
JJ is feeling jealous! He has been the "king" of the house for 9 years and is wondering when is this new little pest leaving?
It's going to take some time for him to get used to the new dog but there are a few things you can do to help ease the transition.
First, whenever the dogs are outside make sure JJ returns into the house BEFORE the puppy. The puppy should be following him inside. It sends a signal to both dogs of who is the dominant one.
When JJ growls or snaps at the puppy, you have to immediately correct him and I use the Cesar Milan technique which is using your hand as if it were a dogs mouth and firmly touch/squeeze the nape of his neck and a "psssh" sound. What you are doing is correcting him as if you were his dog mother. Dogs don't use words and when mother dogs correct their puppies, they give a nudge or gentle bite on the neck to redirect their behavior. This correction has to be swift and immediate when the growling happens. Eventually JJ will get used to JUST hearing you use the "psssh" noise and will correct his behavior when he hears it. It takes time, patience and most of all consistency.
Just as important as correction is reward.
Let JJ know how much you still love him and reassure him that he is NOT being replaced with this new little fellow.
Take him for long walks ALONE - just the two of you.
Give him one on one attention and affection and make your time together special.
Everyone loves puppies and gives them all the attention, making the other dog sad and jealous. Make sure people who come into the house lavish the same amount of attention on JJ as well as the puppy. Have them give JJ a special treat, reinforcing the fact that he is still JUST as special as the new puppy.
Jacks are set in their ways and JJ has been enjoying his one dog status for 9 years. It's going to take some adjustment time for him to accept the puppy. Stay consistent with the corrections and lavish the love and attention on JJ when he is being GOOD. Be patient it could be a while, but things should settle down nicely, eventually!
Good luck, keep up the good work.