Integration

Question
We have an 8 month old xbreed puppy from a rescue shelter, medium sized, we have had him 6 months now. he is extremely social and very playful to the point of damaging neighbours fence to play with their dogs. After much discussions and advice from friends we decided to get another dog. We chose one from the shelter again, a jack russel cross, female about 2 years old. We took our puppy to meet her and they both seemed happy enough, although he is alot bigger than her.

They showed a little aggression and the shelter told us this was normal. We have brought her home and she is adorable although not interested in our pup at all. He keeps sniffing her and wants to play and she is growling. I have made sure I pet him first and then her and introduced them in different parts of property for short periods. As soon as they show aggression, she growls first at him and then he barks and starts showing his teeth, I intervene as the pack leader showing them that I won't tolerate aggression.

Am I doing the right thing? How can I integrate them better and how long does is usually take for them to be comfortable with each other? I'm starting to wonder if I have made a mistake as my pup sleeps in our porch and I feel like I'm closing him out when I seperate them!

Answer
How long have they been together?  It could take a couple months or more for this to work itself out and even longer if you intervene and prevent them from working through it.  Your approach sounds reasonable but you are probably making a mistake by separating them.  The aggression that you describe here may not be aggression at all but simply communication and the two dogs introducing themselves to each other and establishing there position with each other.  By separating the dogs each time they demonstrate this behavior you are not helping the situation.  You should keep them together forcing them to accept each other under your supervision and control.  Considering breed and age I would let them work things out and get used to one another.  It is best to observe the from afar and see how they interact rather than be right their as a immediate part of their interaction.  Also I would allow the dogs to sleep together.  Often dogs will bond during this time more easily than during active time.  Since the pup is a pup and has the tendency to be obnoxious he will certainly get snapped at a few times.  Considering the small dog is a terrier it will have no problem taking care of itself.  Simply insert yourself as you have described if the interaction begins to get to rough.  Remember these are dogs and growling is can really be no more than talking.  Watch the posture of the dog to determine the level of aggressiveness.  The female will of course want to assert herself over the male both because of age and sex.  Just remember that anytime you interject yourself and the dogs cease the aggressive demonstration they should be rewarded immediately with praise and then the process should be repeated.  Spending time putting the dogs into situations where they are close together under your guidance will assist in them getting used to one another.