I'll believe it if I see it" for dogs translates to "I'll believe it if I smell it." So don't bother yelling at them; it's the energy and scent they pay attention to, not your words.
Cesar MillanAll dogs can become aggressive, but the difference between an aggressive Chihuahua and an aggressive pit bull is that the pit bull can do more damage. That's why it's important to make sure you are a hundred percent ready for the responsibility if you own a 'power' breed, like a pit bull, German shepherd, or Rottweiler.
Cesar Millan