These two are classified in the same section because there is only one key difference between the two for purposes of making training plans easier.
Protective aggression is triggered by the instinct of a dog to defend themselves and other packmates from a threat.
This is a clearly observable behavior in all studies of wild and feral dogs and an instinct that humans have taken advantage of in many working dogs.
The term "fear aggression" is a variance of this behavior which is best used as a classifying term instead of protective aggression when the triggers seem to be irrational or inappropriate triggers for a protective response. There may be some gray area as to what constitutes a rational protective response and what would be considered irrational. Further complicating the terms are the expectations of the handler from the dog. For example, a rottweiler that acts aggressively when a stranger walks within close range on a walk is more likely to be called "protective" and a Labrador is more likely to be called "fearful" for the same behavior. Therefore, it is somewhat subjective.
Protective Aggression Examples:
- aggression when a stranger hugs the owner
- aggression from bitch when stranger handles puppies
- aggression when a stranger approaches in a "threatening" posture
- aggression toward a dog that approaches with threatening body postures
Fear aggression Examples:
- aggression toward most approaching dogs regardless of the posture
- aggression toward most approaching people regardless of the posture