Many dogs have a high stress level because of demands resulting from a young age, anger and aggression from the owner’s side, or being constantly commanded to obey, with the owner often using a harsh voice. A dog such as this is stressed by these things every day. As a result, stress levels remain high, and consequently the dog never calms down. This dog will also have a very high degree of self-defense. He is the one to behave aggressively towards other male dogs or people.