My small (35lb) 6 yo female has always been the most loving, non-aggressive dog and got along with my 2 cats and my 12 yo red male dobie. Three weeks ago we brought in a young rescue dog (pit mix) – he’s about 14mo, neutered, housebroken and very smart and affectionate but high energy. We first introduced him to the little one (Asia) as we thought she would be an easier welcome…we were wrong. For the first time in her life she growled, showed her teeth, and went after him. In the past two weeks we lost our beloved dobie and now we are desperately trying to keep the peace between the two young ones but we are becoming increasingly frustrated and are concerned he will pick up and copy her aggressive behavior. I just don’t know how to proceed with getting them to get along.