Recently I saw a show Cesar did with an aggressive Chow and another family dog. It turned out that the dog that was thought aggressive was not causing the problem. A quiet posturing on the part of the Chow caused the other dog to react aggressively.
This is why Cesar always recommends consulting professionals in cases of aggression. You need to find someone who has experience with aggressive dogs, has Cesar's philosophy and can read a dogs body language. You will have to consult an animal behaviorist and interview the person before allowing them to work with your dogs. Ask for references, people you can speak with who have use this person. Sometimes you can find an experienced dog trainer who actually uses many of Cesar's methods and is good at reading body language. So if you can't locate a behaviorist you like, check out your AKC instructors and IACP instructors.
www.dogpro.org
http://www.akc.org/events/obedience/training_clubs/
He shall be everything humanity strives to be: Honest, Loyal, Kind in Heart, and Strong in Spirit. Therefore, you shall call him Partner and Best Friend."
Author Unknown