When Melodee Leiderman got a toy schnauzer last year, the Upper East Sider’s first bit of business was upping the number of guests when she made restaurant reservations.

“I just take her everywhere,” says the mother of two, who claims her pup, Truffles — a non-service dog — is welcomed with open paws at Morton’s and Del Frisco’s. “I wasn’t worried about taking her. I saw everyone else doing it.”

But doggy dining is driving some people barking mad. Restaurateurs say the wobbly balancing act between federal Americans With Disabilities Act rules and city Department of Health regulations have allowed a wave of non-service dogs to dine with impunity.

In June, the NYC Commission of Human Rights issued a new set of legal guidelines regarding people with disabilities. Among other things, it reminds restaurants that they are forbidden to demand proof of either a person’s disability or an animal’s use as a service companion. So, while hosts at Del Frisco’s and Morton’s say that only service dogs are permitted, they rely on customers’ honesty.

Henry Roberts, co-owner of Tribeca’s Two Hands, says he’s been seeing a lot more hungry hounds in his restaurant since the announcement.

“There’s really no way of policing this,” he tells The Post, as he eyes one dog at a table. “Now, people walk in with dogs of every shape and size. There’s nothing we can do — it’s a free-for-all.”

Celebs don’t seem to be complaining. Actor Justin Theroux routinely takes his pit bull, Kuma, to restaurants around the city, including Midtown’s Fine & Rare and the Waverly Inn. In February, Page Six reported that Adrian Grenier and his date brought their dogs to Scarpetta, where the “Entourage” actor told the hostess that the pups were service dogs.

But some diners are less than thrilled.

“It’s gross,” says Danit Sibovits, an Upper West Side lawyer. “I don’t want dog hair or slobber near my food.”

Unfortunately for her, restaurant workers feel powerless to stop the canine takeover.

“I can’t say, ‘Excuse me, can I see ID for this dog?’ It’s like profiling,” says Noel Shu, co-owner of downtown’s Windrose restaurant, which is slated to reopen later this month. “The customer can turn the tables and say they’re being discriminated against. People are definitely bringing in their dogs because they know they’re not going to be asked.”

Although the Department of Health has restrictions on dogs in restaurants, such as forbidding them from actually eating there, food-service workers say those rules are difficult to enforce. For example, if they go after Fido for hopping up on a chair or sniffing the bread basket, they could be committing a human rights violation: Service animals can’t be banned from touching things because they may be performing a critical task for their owner, such as nudging silverware toward them, a spokesperson from the New York City Commission on Human Rights tells The Post.

And dogs aren’t always well-behaved, Shu points out. Once, his restaurant buddy was livid when a customer’s pup jump up and start sniffing diners’ necks. “Who wants to deal with that when eating out?”

Jeremy Wladis, owner of the Flying Fisherman, recalls a German shepherd who ran amok in his previous Upper West Side restaurant.

“It was going after people’s food, and people were pissed,” says Wladis. Nevertheless, he adds, his hands are tied. “You don’t have the legal right to kick them out.”

Longtime food publicist Steven Hall sympathizes with the restaurateur’s plight.

“No one wants to piss anyone off because they’ll go on Yelp to complain they won’t let you in with their service dog — or so-called service dog,” Hall tells The Post. “I think it happens in some neighborhoods more than others. The Upper West Side is a magnet for people who feel entitled to bring their pets or screaming children. And maybe Tribeca is the same.”

It’s true in the Meatpacking District, where Christopher Lee, who manages a restaurant he declined to name, is fed up with furry diners.

“It’s a restaurant,” he says. “You shouldn’t have a dog at a dinner table, but these days, you have a lot of people who get their dog certified as a service animal just to bring their dogs with them.”

Last week, Lee says, a customer hauled in her huge dog, promising he’d lie still. Even so, he says, “everyone kept tripping over this 100-pound dog.” Nor does size matter: Lee recalls another woman’s Maltese, who barked every time the owner took a bite — over the course of a two-hour meal.

“I had to give customers free champagne just to calm them down,” he says. “They’re paying a few hundred for a meal. You don’t want a dog yapping on top of you.”

Then again, Lee says, “How can I say no to them? It can become a discrimination thing. It’s a mess.”

‘People walk in with dogs of every shape and size. There’s nothing we can do — it’s a free-for-all.’

But some restaurateurs are putting their foot down.

“We’ve definitely been booted,” says Kendall Anderson, a 32-year-old decorator from Williamsburg who has a 25-pound Rhodesian mix, Georgie. At her go-to restaurant, which she declined to name, “The owner was watching on the camera and the bartender said, ‘We have health inspectors coming in the next week or so. We can’t have a dog here.’ ”

And some restaurants are exercising their limited rights to ask about diners’ pooches.

“I got questioned the other day if he was a service dog,” says Lee Abbamonte, 40, of his 30-pound French bulldog, Hector. Unlike many, Abbamonte, an Upper East Side entrepreneur, has a certificate proclaiming the pup an emotional-support animal, although according to the guidelines he is not required to show it. (Though the new advisory requires that landlords accommodate emotional-support pets, which unlike service animals do not need any special training, the language is more vague when it comes to restaurants and bars.)

“Usually no one says anything, but sometimes you’ll get bad looks from people,” says Abbamonte, who sometimes sneaks Hector food when they’re dining out together. “Either an owner is nice or an a - - hole. What am I going to do — argue with them?”

Back at Two Hands, Roberts is bracing for a snowball effect. “At a certain point, if everyone brings their dog in it could get a little crazy, and become a health thing if there’s animals everywhere.

“Who knows what’s next?” he says. “They’ll say, ‘What about cats? That’s not fair!’ It’s a slippery slope. I wouldn’t put it past these millennial kids.”