Every time she crosses the threshold of the Pennsylvania animal shelter where she volunteers, Kayla Filoon sees dogs in terrible need.

Some are headed to be euthanized. Others have been abused or neglected.

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But there was something about Russ, a beat-up and abandoned pit bull, that spoke directly to her heart.

"He was just sitting there, all proper, not making any noise, and he had these sad, puppy-dog eyes,” she told InsideEdition.com Thursday.

The 20-year-old college student was instantly smitten. And so, apparently, was Russ, a brown-and-white bundle of gentle affection.

Photos of Russ cuddling with his new owner have gone nuts on social media, with more than 300,000 likes.

“This is like crazy,” Filoon said of Russ’ newfound fame. “Because he’s a pit bull, it’s eye-opening for a lot of people.”

The breed is sometimes considered dangerous because of its powerful jaws, and is often bred and trained to fight and kill other dogs.

“I took him out and we went for a car ride. I bought him some chicken nuggets,” Filoon said, laughing. “He just sat in the passenger seat like a little gentleman. I just knew I was going to adopt him. I got him that night.”

Read: Hero Stray Pit Bull Slashed While Stopping Stabbing Attack Gets Forever Home

Russ has rarely left her side since then. "He always has to be close to me," she said.

She estimates Russ is about 4 years old. She doesn’t know how he came to be roaming the streets of Philadelphia, but believes he once had a good owner.

"He knows commands," she said. "He knows 'sit,' 'down,' 'stay' and 'paw.'"

After two weeks, Russ is right at home in his new home, Filoon says.

“He is the most cuddly dog I’ve ever encountered.”

Watch: Dog Rescued from Neglectful Home Now Wins National Competitions