With the Belmont Stakes just two weeks away, let’s keep some grim statistics in mind: Every year, more than 2,000 horses are killed while racing or training.

Approximately 13,000 retired thoroughbreds are packed off to slaughterhouses. And that’s to say nothing of the hundreds — often in puberty and active racers — who suffer painful and lonely deaths in their stalls each year, from infection or neglect or catastrophic injury.

All in service of a multibillion dollar industry that largely looks the other way.

“They’ve been allowed to operate under this cloak of secrecy for nearly 100 years,” New York-based activist Patrick Battuello tells The Post. But that is beginning to change.

The rampant deaths at California’s Santa Anita racetrack — 25 since December, including a 3-year-old named Spectacular Magic last Monday — have made national headlines. This week’s episode of “Real Sports with Bryant Gumbel” ran a devastating expose of the industry, replete with footage of one-time champions killed in the most heartless and savage ways. Even the storied Jockey Club has called for reforms.

Just as the national conversation about football always includes concussion, viewership and fandom of horse racing should now include talk of these atrocities.

Let’s take what seems the least of it: so-called stall deaths. If only those were as clinical and painless as they sound. These young horses often suffer from laminitis, which causes excruciating hoof pain, or colic or limb fractures or broken necks, crushed spines, blunt force trauma.

“The confinement and the isolation is perhaps the worst of it,” Battuello says. “These are herd animals, naturally social, alone for 23 hours a day. So you often see bobbing and weaving and self-mutilation — these animals are going mad. Doctors will say, ‘The horse was found dead in a stall in the morning.’ That means the horse died alone, in a little 12-by-12 stall, painfully and horribly.”

Dr. Kate Papp, who treats horses at Penn National, told “Real Sports” of a horse she recently found standing on three legs, the other shattered and dangling. “Just the look in his eyes says, ‘Please, somebody, help me,” Papp said.

Trainers often demand that an injured horse be drugged up to race on broken legs and, Papp said, there’s no shortage of unethical vets who’ll do just that. “One injection takes two seconds and makes you $30,” she said. “And if you multiply that by 10 in one day, that’s $300 for five minutes’ worth of work.”

So deplorable are our protections of racehorses that the USDA allows them to be transported for slaughter for 28 hours straight, in cramped trailers, without food or water. “They’re panicked; they don’t understand what’s happening to them,” says Battuello. “When they get to the slaughterhouse, the terror just intensifies.”

A horse is first shunted into a high-walled metal stall. A worker stands above, wielding a machine meant to shock the horse’s brain and render the animal unconscious.

If that doesn’t work — and it often doesn’t — the horse is nonetheless strung up by one leg, awake and upside down, and slashed open until they bleed out and die. The meat is shipped to foreign markets and the rest of the horse is considered waste.

Leaving aside the ethics of sport, let’s acknowledge the human-equine bond. There are very few animals that have helped build our civilizations, fought alongside us in war, evolved for human companionship. In that regard, this bond may be second only to the human-canine one.

And as Battuello points out, we’ve begun a true reckoning with the ethics of animals as entertainment. Ringling Brothers and Barnum & Bailey Circus is out of business.

Rodeos are banned in some parts of the country, with Los Angeles likely next. Sea World never really recovered from “Blackfish.” Four states have shut down greyhound racing.

Can’t we at least get federal oversight for our racehorses — just as a start?

Battuello thinks so. “I’m heartened that the conversation has been engaged,” he says. “You can’t stop moral progress.”