Penni the pit bull was not raised to survive.

From birth, she was locked in a drug-house basement in the Bronx, New York City. At two years old, she was dumped onto the streets with a few other dogs and picked up by police. The abandoned pup had a sore on her rib cage that was developing a tumor. Shortly thereafter, she was brought to a local pound. She was put on a euthanasia list because the place was over capacity.

That's when Fur Friends in Need stepped in. The nonprofit rescue organization scooped up the pooch, helped her heal, and put her up for adoption. Shortly thereafter, Blaine DeLuca came onto the scene.

"I'd been on the prowl for a dog for the better part of six months," DeLuca, an engineer, says. "I knew I definitely wanted to get a rescue. I knew I'd be doing a lot of adventuring, so I wanted a fit dog."

When DeLuca met Penni, he was warned her upbringing might make her standoffish. But the dog, who still had stitches from the tumor removal, walked right up to DeLuca and plopped in his lap. Soon, the pair would be climbing mountains together.

Reintroduction to Life

DeLuca brought his new dog back to his home in New Jersey. Although she had been open to DeLuca, the dog was still anxious and had to be introduced to normal life.

"She was terrified of everything under the sun," DeLuca says. "It was a pretty calculated rehabilitation program I put her through."

DeLuca didn't know if Penni would ever recover from her past abuse. She didn't bark for a year and a half after her adoption, and she had to learn how to run after being cooped up in a basement for most of her life. DeLuca says it was another two and a half years until she started acting like a "normal" dog.

At first, he would take Penni out around town, which was busy with sidewalks, houses, and traffic. At times, Penni would just stop walking and DeLuca would have to pick her up and carry her the rest of the way. But slowly, DeLuca introduced the dog to nature by taking her into the woods during the day.

"She was able to relax," DeLuca says. "It was like a whole different dog when I got her out there."

Adventure Dog

The duo soon began to branch out into more adventurous terrain. Today, DeLuca says Penni has experience with long-distance hiking, high elevations, rappelling, cliff-side scrambles, and zip-lining. He rarely has Penni on a leash when they explore because he's confident she'll stay by his side. The acclimated pooch seems to be doing well.

DeLuca eventually moved to Las Vegas for work, so he and his dog began adventuring through Nevada, Arizona, California, and Utah together. Despite her abusive upbringing, Penni is fearless in the wild. She runs right up to DeLuca when he prepares for them to rappel down cliffs. He says she particularly enjoys playing in the snow, where she runs at full speed and digs her face in "like a bulldozer."

When hiking, DeLuca puts a pack on Penni filled with her collapsible bowls, food, snacks, boots, and—if it gets cold—a pair of fitted pajamas. He says he never puts more than 10 pounds on the 60-pound dog. As an athletic breed, pit bull dogs are known for their weight-lifting abilities.

Russ Boles, a co-founder of the pet blog Wagbrag, says healthy dogs should carry no more than 25 percent of their weight, which varies depending on the age and fitness level of the dog. (Older dogs should carry lighter loads.) He says dogs need to be conditioned for and evaluated during long-distance hikes, because their paws can get easily cut up by rough terrain. Their backpacks should be properly fitted to prevent chafing.

Pit bulls have been stereotyped as aggressive dogs trained for fighting, but DeLuca is quick to debunk this misconception. One look at Penni's Instagram account shows she's a popular pooch.

"We're really trying to help change the pit bull stereotype," DeLuca says.