do you have any history as to why the dog was surrendered? how long have you had her?
I know when I got my doxie rescue last October, he was very determined to be alpha leader. He had a real attitude problem. I worked with the foster mom and she helped me get through to him. Within about a month, he turned around completely and now the greatest little guy in the world.
Dogs don't understand why they are being shuffled around from home to home so some will act out. Doxies are known for their attitude issues but they are also very loving and loyal little companions.
What kind of dog is it (if you know)?