Definition of an Aggressive Dog
An aggressive dog — not to be confused with a reactive dog — is one that has already attacked another dog or animal or has bitten a person. There are many causes for a dog to become aggressive, but what we find most often is that this problem begins at home. The pup is deciding that he needs to take over the role as Alpha in your family (or pack, in the eyes of your pup).
Once a dog has started down this path, it is going to take a lot of work, time, and commitment on behalf of the owner — you — to turn the tables. When you have taken the role of Alpha, your pup will be relieved that he no longer needs to make decisions on what is good or bad, and he will begin to relax.
The key to becoming the Alpha in your family is knowing how to assert yourself as the pack leader. To become the Alpha, you will need to learn to be a trainer and be consistent (relentless) in your training, presenting your pup constantly with new scenarios so as to confirm yourself as the decision-maker in every situation.
Other causes for the development of aggression in dogs may be seclusion, neglect, taunting, baiting, and — last but certainly not least — torture.
In a lot of cases, an aggressive dog is a scared dog. This is where consistent, intense training makes the difference. These dogs can learn to trust your decision-making and begin to relax.
If you have an aggressive dog, the training you will receive will greatly increase your confidence in handling dogs in general, and that confidence will be felt by your pup. Your training will increase your ability to identify situations that your dog is not comfortable with and will teach you how to avoid them/train for them. The training will help you manage your aggressive dog.