1. Ethology - Review territorial aggression and especially what is NOT this type of aggression.  You may need to make plans that address other aggression types as well (reference aggression types here).
2. Health
   1. Be sure the dog is on a quality diet.  It may make subtle differences.
   2. Consider any sight or hearing problems.  Being caught off guard can trigger an aggressive response.
   3. Consider any evidence that the aggression may be related to chronic pain or discomfort.
   4. Consider neutering male dogs in extreme cases.  Testosterone can exasperate the intensity of any type of aggression and is reported as a risk factor in most dog bite studies.
   5. Consider supplementing with Tryptophan and Tyrosine.
3. Diagnosis - After considering ethology and health, if the dog is not your own, be sure to communicate to the owner a clear diagnosis of what the behavior is, what is triggering it, and what may be exasperating it.  It is also recommended to discuss the difference between management, training, and rehabilitation.
4. Attitude - Recognize if there are any poor attitudes that have been formed before understanding the behavior (the dog is a jerk, trying to be the boss, etc..) and attempt to change the attitude based off the true etiology of the behavior before working on a plan with the owner.  Any plans or behavior that are influenced by a poor or incorrect attitude will likely have side effects.
5. Manage - Without much formal training territorial aggression can be managed to prepare for further training or to reduce incidents in the cases where no further training is feasible.
   1. Train the dog to accept a muzzle.  This will be vital for future training and for preventing bites in high-risk situations.  Never take chances or "hope" the dog does well.  Make it impossible for a bite to occur if in a doubtful situation.
   2. Doors in the home are always locked to prevent accidental encounters with friends/family entering that the dog may be aggressive toward.
   3. The yard is secure and entrance locked and/or has a sign with appropriate warning or instructions visible.
   4. Do not tether the dog and leave unsupervised in a yard without a physical barrier between the dog and potential targets.
   5. Always use quality and properly fitted equipment.  (leashes that will not break, collars that are tight enough that the dog cannot back out of, etc..)
   6. If using prong style training collars, halter-style, or other potentially unstable training collars be sure to use a loose fitting slip loop or another back-up attached to the leash snap as a "safety" in case the primary training collar accidentally disconnect.
   7. When possible (and dependent on the risk factors) carry or have within easy access a spare leash, breaking stick, and a spray deterrent such as spray shield.
   8. Use extreme supervision around children or anyone not familiar with the dog's triggers.
   9. Avoid the use of invisible fence systems if possible. Even if it keeps the dog in the yard, it does not prevent people or animals from entering.
   10. If the aggression is around the neighborhood, consider where the dog "marks".  Only allow the dog to relieve self in certain areas.  If possible switch up the route where a dog is walked daily.
6. Leadership - Strict leadership exercises reinforce the management and further prepare the dog for more formal training:  Refresher here
   1. Emphasize the importance of leading from an ethology point of view to make many decisions related to aggression.
   2. Leadership will also effectively establish operations, making all positive reinforcers more powerful during counter-conditioning exercises.
7. Habitation - Strict housebreaking that involves environmental punishment for taking possession of any object that is not given to the dog by the handler can eliminate most situations where there would otherwise be a conflict between the dog and humans.  Also, a dog that is properly habituated to the home, in general, has its needs better attended to and managed by the owner which further eliminates the potential motivation for conflict with visiting humans or dogs. Habitation is best reviewed here.
8. Training - Minimal training recommended for territorial aggression (phase 3 level) Proper leash handling is a MUST!! Leash Ninja Video Here    It is also helpful to be skilled in using leash resistance.
   1. Leave it - disengage focus from an object, dog, person etc..
   2. Look -  Look at the handler in the face until given a different command.
   3. Heel - Walk behind left heel
   4. Come - Come when called
   5. Sit and/or Down
   6. Place, Post, ect - Commands that direct the dog to different places
9. Advanced - Use the training to do these exercises.  Be sure to use the dog training trinity as much as possible during the process.    A muzzle can be used while teaching these exercises around a trigger since it is common for a dog to try biting the handler as an option instead of obeying around a trigger they truly are motivated to attack.
   1. Go to a "place" to or various "posts" depending on if answering the door, in the yard, etc..
   2. "Leave it" is to be used to communicate to the dog that the trigger is not an option to be interacted with, regardless if on any other command.
   3. "Look" is used instead of "leave it" if you want the dog's focus BEFORE the dog has noticed a potential trigger.  Great to use when passing by a dog that you notice is already staring down the handled dog.  It is unreasonable to expect the dog to hold this command for long periods but very useful for short spurts while you and dog are passing or something else passing by.
   4. Various exercises that involve different presentations of triggers that the dog would encounter in everyday life, especially passing by other people and/or people with other dogs if the problem is in the neighborhood and/or drills calling the dog from the fence if in a yard.

Things to consider:

• Personal protection training is often a great outlet for some dogs with territorial aggression toward people.  This training can also enhance the handler's confidence and experience in controlling the dog while highly aroused in an aggressive state. This training should never be done without mastery of basic phase 3 control, a responsible management plan, and leadership exercises in place.
• Safety precautioned should always be exercised with dogs that are capable of inflicting serious injury.  Be extra cautious with dogs that have a known history of skipping steps in the aggression cycle and/or are powerful enough to overpower a person.  Layered clothing with Cordura or leather on the outer layer, protective gloves, and/or other clothing specifically manufactured to protect against dog bites should be used when there is not a physical barrier, restraint, and/or help of a second person between you and a dog that is in early stages of training.  The use of back-ties can also be useful to give the dog freedom of movement while keeping a trainer out of range of a bite.