dog introductions and behavior

Question
Hi Sandy,
Thanks for taking the time to help.  I have adopted a 4 year old female pit-bull from the local dog pound. She was there 18 months and appears loving and affectionate.  She was fixed three days ago and she is becoming more active.  We have a 2-year-old male beagle/rotweiler mix  that is shy and somewhat skittish.  I brought him to the pound to visit the prospective new dog and they seemed to get a long ok.  At home, our dog (male) attempted to bite the new dog.  Since then, the new dog has been aggressive towards our dog.  The new dog seems to be trying to establish her dominance while our other dog is somewhat resistant.  How can I reduce this behavior?  I want them to get along.  In the past, our other dogs have never displayed this type of behavior but I have always had one older, established dog with a new puppy.  The new dog, pitbull 3-4 years  old, our original dog 2 years old.  Any ideas?  

Answer
A good trainer would be a lot of help to you. It's hard to know online if this is something that's going to be a continuing problem, or just a little glitch in getting acquainted. It's normal for your resident dog's nose to be a bit out of joint over a new dog, and for a new dog to be defensive against a dog who has shown aggression towards her. I wouldn't try to think of it too much in terms of dominance, as there are many other possibilities. And as both dogs are of breeds (pit bull and rottweiler) that can be other-dog aggressive, in-person professional help would be best to have, to know how do-able this will be. That said, I wouldn't just let them work it out, but start by doing on-leash parallel walking and working on obedience at a distance on neutral turf, and gradually decreasing distance as they are able to handle it. Sandy Case BFA MEd CPDT www.positivelycanine.com