Often, the pets make an understated entrance. “A lot of times, you won’t even see the dog” until you seat the owners, said Ally Gallegos, a former maître d’ at an upscale neighborhood restaurant in the West Village. “And you’re like, ‘Oh, God.’”

What happens next is straightforward, at least in theory. The Americans With Disabilities Act allows the staff to ask just two questions: Is the dog a service animal, required because of the owner’s disability? And what work or task has the dog been trained to perform? This should mean that service dogs get in with no problems, and other pets are gently redirected outside. (Pets are allowed on outdoor patios at the restaurant’s discretion.)

In practice, this is often not what happens: “People are afraid to deny a dog,” said Thomas Panek, the chief executive and president of the nonprofit Guiding Eyes for the Blind, in Yorktown Heights, N.Y. (Mr. Panek, who is legally blind, is assisted by a service dog named Ten.) A result is that, over time, “they have all these bad experiences with dogs that really shouldn’t be in the restaurant.”

“You’re getting into hundreds of conflicts of varying degrees of intensity every shift,” said Lindsey Peckham, a hospitality consultant who has worked in some of the city’s most acclaimed dining rooms, including Eleven Madison Park. “You’re like, this isn’t the hill I’m going to die on.”

Ms. Peckham recalls a time when “dogs in restaurants were a very rare exception.” Then, she said, came the proliferation of emotional support dogs, which do not legally qualify as service animals, but sound as if they do. And in the return to post-pandemic normalcy, she theorized, many New Yorkers wouldn’t — or couldn’t — leave their dogs at home. “So all of a sudden, dogs are everywhere.”