New Jack Russell Puppy

Question
I have a 2 year old female jack who gets along with most other dogs. She goes to the dog park regualarly and gets regular excercise. So, when we decided to get a new jack puppy we thought it would be fine with our old one. WORNG! We made the mistake of introducing the new male puppy to our old one in our home (which I read now was a big mistake) and our 2 year old, Molly, was very agressive and territorial. Should we try to start over and let them meet again somewhere else? Molly got very stressed and we had to seperate them almost immediatly. Please, any help will be appreciated.

-Brian

Answer
Hi Brian,

Congratulations on your new puppy (I think!)
It's actually a little late for introductions because Molly knows about the other dog and has his scent now.... but that's OK, you're just going to have to work hard at training Molly to accept this new little intruder. :)
Where is the puppy now? If you took him out of the house and have kept them separate, then yes re-introduce them outside and let them "play" outside for a little while. Keep a leash on Molly in case she gets jealous again, you'll have to pull her away.
Definitely don't ever leave them alone together and be consistent with your approach to training Molly to be non aggressive.
She has been the queen of the house for two years now and is feeling that she may be being "replaced" - it's important to give her some alone time with yourself, (still take her to the park, etc..),  give her some extra attention, don't share her toys or bed with the new puppy and mostly don't let her feel that you are nervous. Stay calm and be the boss, and don't let her show any signs of aggression at all. Correct immediately at any sign of aggression with a NO and a firm touch to Molly. Praise and pat her later when she is being good with the puppy. If you have a partner at home, the two of you should sit together with the dogs, each holding one and then switch dogs after a while - to show Molly that she is still special to each of you, but that this new puppy is here to stay too. It will take some time and consistency but you can do it.  Spaying and neutering will help with the aggression too (if Molly's not already done). Make sure you especially neuter the male because as he gets older, he is going to want to dominate the female and those male hormones will make him pee all over the house trying to make it his own.
Consistent and firm correction and training.
Consistent and loving praise when Molly is being "good". Praise her for just laying there!
Send clear authoritative messages to both dogs (you're the boss).
Give special alone time/attention to each dog.
Hope this helped, write anytime.
Carol