In tonight's episode of "Cesar 911" I show how the combination of a fearfully aggressive dog and a timid owner creates a vicious cycle. It's up to the human to step into the leadership role to resolve the problem. Watch tonight at 9/8c on Nat Geo Wild. | Cesar Millan

In this Cesar911 Episode, I help a family whose dog barks at everything! The mom's son, Mason, is scared to even enter the house because the dog makes him feel uncomfortable. He is afraid that the dog, Buddy, will lash out. #betterhumansbetterplanet Full Video: https://youtu.be/1ln5lpH5Nf0 | Cesar Millan

My toughest task yet. In this clip of Cesar 911, I meet a dog that bites an innocent bystander. Could this be the first dog that I can't help? Stella is a Weimaraner with a killer instinct. She attacks dogs and humans and if the issue isn't deal with right away, I fear something terrible can happen. | Cesar Millan