Dogs competed in a ‘smile-off’ contest at the National Dog Show preview. Everybody won.

Two dog breeds renowned for their uncanny smiles — the Lancashire heeler and the Samoyed — were pitted head-to-head in a “smile-off” contest at the National Dog Show press preview Tuesday, shepherding in howls of laughter from the crowd and confused head tilts from the contestants.

These noble descendants of wolves, bred to strike fear in the hearts of livestock with their impeccable herding skills, just had to grin and bear the attention lavished upon them. Sometimes being man’s best friend is ruff (and very silly).

The news conference at the Hilton Garden Inn Valley Forge/Oaks is held to get people pupped up for the main event this weekend at the Greater Philadelphia Expo Center at Oaks, where more than 1,900 dogs will compete for the title of “Best in Show” over two days.

This is the first time the Kennel Club of Philadelphia, which hosts the National Dog Show, has held a smile-off contest. As it turns out, getting herding dogs to smile on cue is a lot like herding cats. People lobbed treats in the air, made prolonged kissy-face sounds, and somewhere in the distance, someone repeatedly squeezed a squeaky toy to try and get the dogs to smile (no word on whether it was a Busy Bee).

Unable to choose between the toothy canine grins, judge Steve Sansone, a member of the board of directors of the Kennel Club of Philadelphia, awarded the title of “Best in Smile” to both dogged competitors — Kanji, a tiny-but-mighty 5-year-old Lancashire heeler from Cape Cod, Mass., and Prince Louis, a big-and-fluffy 6-year-old Samoyed from Clementon, N.J.

King Edward, whom presenters said was Prince Louis’ 11-week-old grandson but I’m pretty sure was the offspring of a cloud and polar bear, was awarded the title of “Reserve Best in Smile.”

The contest was inspired by the introduction of the Lancashire heeler into the National Dog Show for the first time this year. The breed, which is considered rare with only about 5,000 dogs worldwide, is known for its “Heeler Smile,” which emulates a human smile, according to the American Kennel Club.

The Samoyed’s smile, which is characterized by “slightly curved lips, preferably black in color,” is a breed standard for the group, but it also serves an evolutionary purpose — to stop their drool from freezing when it’s cold out, according to the AKC.

While some breeds are predisposed to smiling, it’s typically to illustrate submission or relaxation and not sheer joy. Thus, it’s often referred to as a “submissive grin.”

Following the smile-off, the winners and about a dozen other dogs on hand for the news conference — including one who shares his name with a brand of vacuum cleaners (Dyson), one whose name was inspired by a color-matching system (Pantone), and one named after a Japanese horseradish (Wasabi) — were sworn in as National Park Service “Bark Rangers” by Adam Gresek, a ranger at nearby Valley Forge National Historical Park.

With paws raised (kind of), the dogs swore to ensure their humans would bag up any waste, always keep them on a leash, respect wildlife, and know where they’re allowed to go in the parks. The dogs were then bestowed with nifty Bark Ranger bandannas (for more information about how your dog can become a Bark Ranger, visit NPS.org).

This year, a record number of breeds — 205 — will compete at the show and you can compete with your friends and family to see who can pet the most floofs at the event.

The National Dog Show is the only benched dog competition in the nation this year, meaning that when the dogs aren’t competing in the ring, they stay in a specific area on the expo center floor so the public can walk around and see them up close. Ask nicely, and owners are likely to give you permission to pet and boop the snoots of their prized floofs — just don’t mess up their perfectly coifed hairs.

Want to meet or interact with a specific breed? Attendees are given programs that outline where every dog’s bench and breed are located.

The 1,940 purebred pooches, ranging from Chihuahuas to Great Danes, will vie for the title of the best in their breed, then best in one of seven groups (sporting, hound, working, terrier, toy, nonsporting, or herding), before the champions move on to compete for the much-coveted title of Best in Show. The pups and their people hail from 40 states, D.C., and five foreign countries.

This year, the Chesapeake Bay retriever is the most-well represented dog, with 54 contestants, followed closely by the the golden retriever, with 52.

On Saturday, the show — which began in Philadelphia in 1879 and has run continuously in the area since 1933 — will be filmed and later televised at noon Thanksgiving Day on NBC, following the Macy’s Thanksgiving Day Parade, as it has been since 2002.

NBC executives were inspired to air the show on Thanksgiving by the 2000 Christopher Guest movie, Best in Show, which is set in Philadelphia and lovingly satirizes the world of dog shows. Those who attend Saturday’s taping and competition are asked to keep the winner secret until the broadcast airs (a separate Best in Show winner is named at Sunday’s show).

Aside from competitions in the ring, there’s also a vendor marketplace, dog agility demonstrations, and a therapy dog booth where members of the show’s Therapy Dog Ambassador Team will be waiting to give free hugs and kisses.

Alice Hoersch of Hatfield, who runs the therapy booth, was at Tuesday’s news conference with Dyson, her 6-year-old Shetland sheepdog. She said Dyson, who works at hospitals and retirements homes, is extremely chill and only has two weaknesses.

“He’s bombproof except for squirrels and birds, then he becomes like the dog in that movie Up,” she said.

The National Dog Show runs from 8 a.m. to 6 p.m. Saturday and 8 a.m. to 5 p.m. Sunday. Tickets for adults are $20, tickets for children 4-to-11 are $10, and kids 3 and under are free. Tickets can be purchased in advance at nds.nationaldogshow.com or at the door.