They say you can't teach an old dog a new trick, but apparently you can teach a series of dogs — all named Sport — the same trick: namely, fetching a cold beverage from the refrigerator.

That's the task Brainerd area resident Kris Scheller started teaching his dogs in the mid-1980s. It's a skill that has given him and his dogs more than their share of 15 minutes of fame, with appearances on "Late Night With David Letterman" and other TV programs over the years.

Scheller, 63, said his adventures in dog training began in 1985 when he gave his recently widowed father a black Labrador puppy for Christmas. But his father didn't want the dog, so Scheller kept it and named it Sport.

Scheller, a fan of David Letterman, liked the occasional "Stupid Pet Tricks" segment on Letterman's late-night show, so he decided to try training his new dog.

It did not go well. Scheller had to pay for the dog training book he got from the Brainerd library, "Paul Loeb's Complete Book of Dog Training," because Sport chewed the cover.

But eventually, Scheller was able to teach Sport to get a can of beer out of a cooler. It was funny enough to get him and Sport on Letterman's show in 1989. He also made appearances on "America's Funniest People," "American's Funniest Home Videos" and the "Maury Povich Show."

Sport also made appearances at Treasure Island Resort and Casino in Red Wing. Sport lived for about 15 years. But his successor, Sport 2, was not to be outdone. He appeared on David Letterman in 2009, this time answering and hanging up a landline telephone. (Scheller said that trick was inspired by the horse trained to pick up a phone on the old "Mister Ed" sitcom.)

In 2011, he made a video of his next dog, Sport 3, as an entry in the Doritos "Crash the Super Bowl" competition for fan-made commercials.

"I spent $600 to have a videographer take it," Scheller said. They didn't win the competition, even though Sport 3 was able to answer and hang up the phone and get a can of Pepsi Max from the refrigerator.

Sport 4 is another good boy, but according to Scheller, not so motivated to learn tricks.

So recently Scheller acquired another puppy, named Sport 5. In nine months, Scheller has taught Sport 5 to open the refrigerator and take out a can of nonalcoholic beer or a can of Dog Brew by Busch (a pork bone broth meant as a canine beverage). Sport 5 will then dutifully push the refrigerator door shut and hand Scheller the beverage. He'll also take an empty can away and drop it into a waste can, operating the step-up lid with his paw.

Scheller is hoping that a TikTok video he made of Sport 5 will be good enough for an appearance on a TBS show called "Stupid Pet Tricks."

All of the Sports have been black Labs or Lab mixes, although Scheller also once had a yellow Lab named Buddy who appeared in print ads.

He said he's used a treat-based training method to get his dogs to do tricks, breaking up a complicated set of behaviors into individual steps like hold, retrieve, shake and drop.

"Everything I learned, I learned from that book that's chewed up," Scheller said. "It's just something to do. It's a hobby."

But just because Sport 5 can do a lot of tricks doesn't mean he's perfectly well behaved.

"I can't get him to stay off the counter," Scheller said.