Carpet stained with Dog Odor?

I just moved into my new house and there is a HORRIBLE odor of Dog urine. The rental company I am working with claim they professionally washed the carpet, but the smell remained. I thought the scent may have been in the walls so i bleached ALL of the walls in a 2 story house. We then put odor deodorizer (baking soda) on the carpet, and let it sit in for a day, the next day we vacuumed. The smell still remains! I have carpet in the bed rooms and hardwood floor in the dining room and living room, sun room, and kitchen. What do you guys recommend me doing? What could get the smell out?