A Calgary dog climbed a few showbiz rungs in an appearance with David Letterman on the "Late Show" Tuesday night.

Lexi, a rescue Labrador-Collie mix, made an appearance on the show's "Stupid Pet Tricks" segment to show off some of her acrobatic skills.

The six-year-old pooch was accompanied on stage by her owner, Chris Jansen, who encouraged her to climb up a ladder. Letterman held the ladder steady as she scampered her way to the top.

She hesitated for a moment, and then leapt into her owner's arms, drawing applause from the crowd and the "Late Show" host.

"That was heroic," said Letterman. "What a dog."

Jansen says despite the bright lights of the New York soundstage, Lexi thrived under pressure.

"Lexi is a high energy rescue dog," he told CTV News Channel. "When we're not around a busy environment, she's looking for stuff to do … In busier environments, she really behaves well, she really listens to me and she really pays more attention to me."

A YouTube video, posted by Jansen's wife, demonstrating Lexi's trademark tricks caught the eye of one of the show's talent coordinators. And last week, Lexi, Jansen and his wife were flown to New York to audition for the show.

"It didn’t really faze me because we've done demonstrations before, and the more hectic the environment the better she performs," Jansen said. "It really worked in her favour."

Jansen worked carefully to teach his dog how to climb a ladder. He says he starts slow when teaching her new tricks, but because of Lexi's intelligence she progresses quickly. Once Lexi got her paws up on a ladder, it didn't take long for her to climb that first step.

"We just grabbed a ladder and put her front paws on it and she wanted to go to the second step, but I didn't let her," he said. I put her back paws on it so she understood what it was, and the next day she was at the top."

In total, Lexi can perform nearly 40 tricks, including jumping posts, walking down the railings of stairways and urinating in the toilet.