The bond between pets and their human is amazing, powerful, touching, inspiring and really, really annoying if you’re seated next to them on a packed airplane.

That’s happening more and more these days as thousands of Americans catch on to this generous scam of airlines. The con is that passengers can claim they need the dog or cat’s company for “emotional support.” Airlines simply require a health professional’s letter confirming the need for such support. Apparently, few doctors have the emotional fortitude to deny a paying patient such a letter.

It’s one thing if the four-legged passenger is a genuine service animal. Transportation companies are required to accommodate them under the Americans With Disabilities Act.

But there’s also the Air Carrier Access Act of 1986, which broadens the requirement to animals “providing emotional support.”

The means a lot of different things to pet owners and non-pet owners.

The result is a rapidly-growing number of jammed airliners taking off like flying kennels. Last year U.S. airlines flew more than 750,000 emotional support animals — for free. As in, so very much cheaper than boarding the little darling back home and considerably less than shipping the animal in the cargo hold, which can also be dangerous.

According to one air carrier survey, that was an 80 percent increase in freeloading flea bags. Just kidding.

The trouble, of course, is the difference between a tiny, well-trained chihuahua in a carry-bag under the next seat. And, say, a gorgeous St. Bernard slobbering its way cross-country 0r a large, panting Labrador discarding its winter coat with everyone nearby.

Or how about an emotional support duck? Or peacock? Both have flown as emotional support creatures. Airlines are concerned about breaking the law with limits and sincerely don’t want to appear inconsiderate of those with PTSD or vets with retired war dogs, for instance.

But paying passengers who draw their emotional support from devices with Airplane Mode did not pay a large sum of money to ride on an Ark. Delta and United have begun cautiously tightening rules on verification letters, which some websites provide online with no real consultations.

The challenge of freeloading, four-legged passengers could be addressed by some kind of congressional legislation. Yeh, right. What pol is gonna crack down on pet-travel entitlements in an election year?

Better yet, might be some clarifying regulations from the Transportation Department requiring certification of passenger and pet health and training (for the animal). That should take — what? — only a few years.