The pets, head scratches, and smiles start before we even get to the terminal.

A young woman in line for security asks for permission and then strokes the lumbering Bernese Mountain Dog. A TSA employee checking IDs reaches down to gently tousle the fur on top of his head. And other folks working the body scanner crack a grin after the four-legged floofer, outfitted in a blue-and-black plaid vest advertising “Pet me!”, emerges from the metal detector.

I’m at Denver International Airport (DIA) on Halloween shadowing Shogun, a 7-year-old pooch who’s one of over 100 animals in DIA’s Canine Airport Therapy Squad (CATS) program, and his joy-inducing effect on the masses becomes quickly apparent.

“The goal of the program is to excite and delight our customers and also to relieve stress,” says Karla Grahn, volunteer program manager of CATS, which celebrated its fourth anniversary last month. And just based on my observations of Shogun’s late morning shift, that goal is most definitely achieved.

Like Shogun, all members of the CATS program are trained and registered with a recognized pet therapy association. Their human handlers sign up for airport shifts on a volunteer basis with the goal of having, on average, four CATS present per day. Currently, there are 109 animals in the program (108 dogs, plus one actual cat), with an additional 13 canines joining the squad by the end of this month, says Grahn. It’s good timing, as DIA expects to see about 190,000 travelers, on average, per day between Thanksgiving and New Year’s Day alone.

Over the course of his two-hour shift, as Shogun and his owner Yasuko Tsunekawa meander gate-to-gate in Terminal B, the Lafayette-based pup elicits approximately 87 pets, five photo requests, at least one hug, and too many smiles to accurately document. In an environment typically synonymous with stress, Shogun seems to uplift all types of travelers—from the toddler clutching a polka dot fleece blanket who wraps both arms around him, to the United Airlines pilot who starts speaking in baby talk, to the trio of elderly women who serenade him with a harmonized a cappella song about angels (yes, this was as lovely/strange as you might imagine).

Courtesy of Denver International Airport

There’s also the middle-aged woman who plops down on the floor and shakes his paw, the employee at Que Bueno! Mexican Grille who runs from the restaurant (seemingly mid-shift) to greet him, and the older gentlemen who coos to Shogun: “You’re beautiful, yes you are.”

As Shogun patiently absorbs the attention like a seasoned celebrity, Tsunekawa, in a matching blue-and-black plaid vest, chats up travelers and passes out his official CATS business cards, which contain a handsome professional headshot and important facts about the 89-pound gentle giant (his favorite activities are hiking and napping; his pet peeve is “being left behind”).

For pet-loving travelers eager to experience the “Shogun Effect,” the airport’s official Twitter account, @DENAirport, regularly posts updates on where CATS members may be stationed on a given day, and employees working the information booths in each terminal can also direct folks toward the animals.

The feel-good vibes that CATS members spread seem to work both ways. Shogun loves people—especially children and babies—says Tsunekawa, 54, and the best part about being a therapy dog handler, she explains, is making people happy. “Pretty much every single person [says] thank you,” she says. “You cannot buy the thank you from somebody.”

Alas, after nearly three years with CATS, Shogun, who’s on the older side for his breed, will retire from the program at the end of November, Tsunekawa tells me. Currently, he’s the only Bernese Mountain Dog in CATS, but that will soon change in a few weeks. Two of the newest pooches joining the squad are also Berners.

Right around Thanksgiving, Syrah and Merlot (yup, actual names) will start roaming the airport terminals, taking their crack at combating travel stress—one pet, head scratch, and smile at a time.