Dog Whisperer with Cesar Millan

Cesar Millan goes back to the basics in the Season 6 opener by adopting four puppies into his pack and demonstrating how to avoid dog-behavioral.

Mary Jane rescued lab-mastiff mix, Cujo, from a bad home.

A French bulldog used to be friendly with strangers, but for unknown reasons, his behavior changed suddenly and he became aggressive.

French bulldog Hardy suddenly goes from being a friendly resident salon dog to snapping at strangers and even biting a few clients.

Life coach and fitness trainer Jillian Michaels whips clients into shape, but when it comes to her greyhound mix Seven, she is at a loss.

Two German shepherds get along fine when they're at home, but when they go to doggy day care, it's another story.

Fitness coach Paul Watson can't stop his great Dane, Willow, from biting at him. Cesar travels down under to tame Willow's wild side.

A Weimaraner is aggressive towards anyone who turns on one of the motorized bikes used to deliver the mail; an aggressive shar-pei; an Australian red.

A border collie's dangerous obsession with moving water is addressed.

While any size dog can become aggressive, several breeds seem to have the worst reputations. Some have even been banned in certain areas of the US.

Josh got his dream dog, a Siberian husky named Spike. But sweet-tempered Spike became increasingly hyperactive, jumping and nipping incessantly.

Cesar comes in to help twins with their Chihuahua-Pomeranian mix that bites.

When Susan MacDonald met Cobar, an Australian Koolie dog, she thought it would be a match made in heaven.

A rehabilitated wheaten terrier mix named Tillie, grows overly attached to art collector Joel.