When it comes to the danger of pit bulls, some of you are really worried, like Verify viewer, Lisa Shannon.

“I'm concerned with the number of pit bull attacks and mauling that's been happening,” Lisa said in a video she sent to Verify.

On Facebook, I've been hearing from a lot of pit bull owners who say don't blame the breed, blame the dog owner. Lisa is still wondering.

“My question is, are they more dangerous than other dogs?” Lisa asked.

To learn more, I'm spending the day with Ray Rentschler. He's the top dog catcher in Arlington, Texas. And pit bulls? He sees a lot of them.

“It's a big dog. It's a strong dog. They've got big powerful jaws. When they bite, they can do a lot of damage to somebody,” Ray says.

Arlington Animal Services ranks dog bites on a scale of 1 to 6. A level 6 is fatal.

“When you get into those high-level classifications, how much is coming from pit bulls?” WFAA asked Ray.

“This year we've had 10 level 4 bites. Out of those, 5-of-the-10 were pit bull type dogs,” he answers.

The Pit Bull’s Bite

Today, Ray and his crew are chasing a loose pit bull. This dog is fast and tough to corner, running in and out of people's backyards. Turns out, this dog has a home, but he's malnourished and might be sick. Ray’s staff takes the dog to the vet.

One common belief about pit bulls is they have a different kind of bite. Some even think it has a locking jaw. What I want to know from Ray is does a Pit Bull have a different kind of bite?

“Pit bulls, when they fight they'll get into, what I call it, a zone and they lock in. They get ahold and they jockey for position,” Ray says.

“So, they just hang on. It's not that their jaw is locked up, or anything. But they hang on. It creates a more vicious bite,” he added.

Do pit bulls have a more vicious bite? I'm bringing in an expert. Dr. Jessica Lockhart is one of about 50 Certified Applied Animal Behaviorist in the world.

“Does a pit bull have a clamping mechanism, where they clamp on when they bite?” I ask her.

“No,” she answers.

“With any dog that's being aggressive, despite its breed, any dog in that situation is going to bite and hold,” Jessica says.

“So, it’s not just pit bulls?” I ask.

“Right. It's not breed specific to pit bulls,” says Jessica.

She says the pit bull has a bigger mouth and, therefore a bigger bite. But bottom line, she says, all aggressive dogs bite and hold.

Pit Bull Aggression

I’m back on the streets now with Ray now, and he’s showing me where he keeps the dangerous dogs. That’s where we find a pit bull named Poseidon, who’s lunging at us, from behind an 8-foot high cage. In court proceedings, Poseidon has been ruled by a judge to be a dangerous dog.

"Whoa!" I say, as Poseidon starts to growl at us.

“We're not going to take him out to play,” Ray says.

“That dog scared the crap out of me,” I tell Ray.

“Me too. That's a very dominant, aggressive dog,” says Ray.

“What did that dog do?” I ask Ray.

“He was running at large and he attacked a man who was sitting in his garage and bit his arm and ripped it open where all his muscle was exposed. That (breed of) dog is so strong and so powerful that when it does attack, they just do so much damage,” Ray says.

That’s an example of a dangerous dog. But, in the town of Anna, I met up with 5-year old Mason Barbay and his mom Kyndal. They love their two pit bulls.

When I began reporting on this story, I admit, I was a little afraid of pit bulls, but the Barbay’s dogs put me right at ease, even licked my face.

“How are they around Mason?” I ask Kyndal.

“Awesome. They're inseparable. They just run around with him and cuddle on the couch. He lays on top of them. They lay on top of him,” Kyndal says.

Most of what we know about dog attacks comes from the news. The website www.dogsbite.org says pit bulls contributed to 65 percent of fatal dog attacks in the last 12 years. But the news only covers the worst cases. In fact, there is no stat that captures all bites, by all dog breeds.

But there's another way to get at this. A widely-cited research study that surveyed dog owners about aggressive behaviors. It’s called breed differences in canine aggression by Deborah Duffy, Yuying Hsu and James Serpell.

In the category of a dog's aggression against other dogs, pit bulls score high. The breed measures about the same as a Chihuahua but below the Akita.

Another loose dog Ray sees a lot is the Chihuahua. And in that same research report, Chihuahua scores really high on aggression towards people. Pit bulls are in the middle of the pack.

But, while Chihuahua's have been known to do some damage, it's pit bulls we're worried about. The perception persists that they are a highly aggressive dog.

“Completely wrong for that breed,” Jessica Lockhart is saying. “They are actually very sociable and very affable breed. They are a very friendly breed,” she says.

So, what did we learn?

• Pit bulls are about average when it comes to aggressive behavior towards people.
• They are high on the list of aggression toward other dogs -- but not the highest.
• And even though a pit bull is strong enough to do a lot of damage when it does bite -- it does not bite differently than any other dog.

If you’ve got something you’d like me to look into, I’d love to hear about it. Send an email to david@verifytv.com.