This is definitely the biggest problem for many dog owners. Aggression takes the fun out of having and dog and adds a high level of stress and fear that the dog is going to hurt someone. First we have to understand that aggression is a normal behaviour in all dogs. There is good aggression and bad aggression. The difference between them is that good aggression is based in the dog’s natural protective instincts and bad aggression is based in fear or an unsound temperament. Aggression can also be influenced by experience be it good or bad aggression. For example; mailman comes, dog growls, mailman goes away. This reinforces the dog’s aggressive behaviour by thinking he chased the man away and through repetition by the end of the week the dog is lunging at the door barking at the mailman. There are many levels of aggression that range from body language, prolonged eye contact, growling, barking, snapping, and then the bite. There are also many different reasons that a dog displays aggression and just as many ways to treat the problem. Understanding why the dog is aggressive and how the problem developed in the first place is the key to long term success in treating this behaviour.