PHOENIX -- Ever wonder what your dog would do if a burglar broke into your home?

CBS 5 News investigates and put to the test man's best friend.

The dogs chosen were named Brutus, Nico, Champ, Buddy and weighing in at a whopping six pounds -- Zorro.

"Most people would like to believe their dogs would protect them," said Leighton Oosthuisen, a professional security dog trainer. He owns and operates Partners Dog Training in Cave Creek.

Dogs like Jedi take years to train and serious cash. Leighton said people who are dedicated to having a dog as security can spend up to $40,000 training a dog to attack or not attack on command.

For the CBS 5 News test, the owners left the house and drove away. The trainer dressed up as a burglar and then broke in.

First up -- Nico, a black labrador. The owner had no idea what to expect.

Nico met the fake burglar at the door, didn't bark and was friendly. In fact, he wanted to play.

"Some may bark, some may growl, but once you open the door they'll pretty much welcome you in," Oosthuisen said.

Or will they? Champ's owner was absolutely sure he would be protective. At first, he showed promise when the would-be burglar opened the door. But, a few seconds later, Oosthuisen, was playing with Champ in the owner's living room.

"I was pretty sure that he was going to bite him, but he said he let him through and let him walk around in the room so, it's kind of disappointing," said Tim Wuolle, Champ's owner.

But the Leighton didn't think Champ failed the test.

"He is the best of all the dogs we've tested so far," Oosthuisen said. "When I pushed through the door and I kind of showed him, I was coming inside he was not going to give space just because of that."

Next up, Brutus, who barked, but quickly retreated, leaving the trainer to wander the house freely.

Brutus barked for about 10 seconds and then went right up to him and was friendly as could be.

While pit bulls may have the reputation as being ferocious, Buddy showed none of that.

In fact, when Oosthuisen pretended to attack, Buddy jumped on him in a playful manner.

"They're not protective unless they are trained to be protective and despite the fact a lot of people think they're going to protect them, the truth is in most cases they won't," said Oosthuisen.

Finally, CBS 5 put Zorro to the test.His owner believed he would tear off the intruder's ankles.

But even though Zorro had the heart of a lion, he backed down and eventually allowed Oosthuisen to pick him up as they settled in to watch a little TV.

"This dog was actually in many ways more defensive of his territory than what a lot of the other dogs were," Oosthuisen said.

Zoor's owner, Carrie Marchese, said she thought Zorro was going to rip the burglar's ankle off. "I am surprised," Marchese said.

"It's a misconception," Oosthuisen said. "About 95 percent of dogs unless they are trained will not protect their owners or homeowners or the homes they are in."

If you want to find out more about training your dog, whether you want to spend hundreds or thousands, click here for the information.