The veterinarian, dressed in candy-cane-striped overalls and a fuzzy Santa hat, presses a stethoscope to the woolly reindeer’s chest. He carefully inspects a front hoof and runs his hand over the animal’s bristly haunches. Then dutifully scribbles on a clipboard.

“After thorough examination,” he says, gazing solemnly at the video camera, “I can tell you that Santa’s reindeer are perfectly healthy and ready for their flight.”

The veterinarian is Joseph Kinnarney, president of the American Veterinary Medical Association, and the recently released video of his reindeer checkup marks the fifth year the association has issued a detailed certificate of health for Santa Claus’s sleigh-pullers - complete with a checklist of ailments afflicting reindeer both mortal and magical: No sign this year of chronic wasting disease or “eggnogosis” in Santa’s herd.

Really? Oh, yes, Virginia: The good doctor even has his own “Official North Pole Identification Number” to show you.

The AVMA is hardly the first group of respected adults to get a little carried away by holiday nostalgia — or the allure of good PR — and throw its weight behind the wink-nudge myth of Saint Nick; even government agencies have done the same.

But by putting a seemingly official stamp on Santa, these campaigns add another dimension to the spirited seasonal squabble over whether parents should lie to their kids about Kris Kringle: Is it just an extra helping of holiday magic? Or are these otherwise serious institutions creating credulity and confusion in impressionable young minds?

If you ask David K. Johnson, an associate professor of philosophy at King’s College in Pennsylvania and author of a new book, “The Myths That Stole Christmas,” it’s definitely the latter. The government and other official bodies should steer clear of mixing fact and fable, he says.

“If parents want to lie to their kids, then let them do it,” he says, “but don’t present them with the fodder to keep it going.”

Societal institutions, however, have done the opposite for more than a century. The media famously vouched for Santa in 1897, when the New York Sun assured a dubious 8-year-old that Claus certainly does exist: “Virginia, your little friends are wrong. They have been affected by the skepticism of a skeptical age,” the paper editorialized. (No word on whether Virginia canceled her subscription when she grew up and learned the truth.)

The U.S. Postal Service followed suit in the early 1900s with its popular “Letters to Santa” program, assigning St. Nick a legit North Pole address. And there is, of course, the famous “Santa Tracker,” operated by the North American Aerospace Defense Command (NORAD), which claims to use satellite data and “Santa cams” to monitor St. Nick’s progress as he circles the globe every Christmas Eve.

To be fair, the Santa Tracker — which celebrates its 60th year this month — didn’t start as a deliberate deception, NORAD officials say. In 1955, a Sears Roebuck & Co. ad misprinted a phone number for kids to dial Santa and the calls were instead connected to a NORAD hotline used for national emergencies.

The director of operations at the time, Col. Harry Shoup, recalled the mishap in a 2009 interview he taped for NORAD: “The red phone rang, and it’s either the Pentagon calling or the four-star general,” he says in the video, his voice gruff, his silver hair neatly combed. “So I picked it up and I said, ‘Yes, sir, this is Col. Shoup.’”

After a few moments of silence, a small child’s voice piped up: “Are you really Santa Claus?”

Shoup thought it was a joke. But when the little girl earnestly repeated her question, he played along. “I said, ‘Yes, I am. Have you been a good little girl?’”

Henceforth, his office began giving all its young callers a “current location” for Santa. The program has since grown into a wildly popular and increasingly sophisticated effort, with a multilingual website and a vast following of devoted Santa fans on Facebook and Twitter.

But that’s a problem, Johnson says. “You have trusted agencies like NORAD or the AVMA presenting evidence to kids to try to keep them believing. They’re taking a side on this issue,” he says, “and it’s the wrong side.”

Despite these worries, plenty of people have clearly emerged unscathed from childhoods spent happily believing in Father Christmas. Numerous psychologists maintain that the Santa lie is just fine, even healthy. And the public generally embraces companies and organizations that get on board with the story.

Kim May, director of communications for AVMA, says that the response to the reindeer checkup video has been “incredibly positive.” It has helped humanize the agency, she says, and convey important pet safety tips.

“I certainly respect the concerns, but we feel like the adults are loving this, and they can counsel their children,” she says. “And if they don’t like it, they’re not going to share it with their kids.”

For the record, Johnson says, he’s not actually proposing a moratorium on Santa. He says he knows families that participate in all the de rigueur Santa activities — mall visits, parades, the plate of cookies — but their kids know it’s just pretend. There’s an important difference between imagining that Santa is real and believing it, Johnson argues.

And even believing in Santa isn’t all that bad, he says. The problem is when parents actively perpetuate the myth, even after a kid starts doubting it.

“It’s one thing to play the game and let children believe what they want, and then when they ask for the truth, you tell them the truth,” he says. “We should celebrate it whenever they discover the truth. We should encourage that kind of critical thinking, not try to stifle it.”

Well ... easier said than done. When the little girl who called Shoup asked him exactly how Santa manages to pack so much traveling into a single night, Shoup, like so many parents put on the spot by inquisitive kids, decided to double-down on the myth.

“If anybody asks, you just tell them, that’s the magic of Christmas,” Shoup recalled telling the child. “And they better not ask any more questions.”