That group might well include the couple whose elderly dog had a pet peeve about being stuck in New York traffic. “They had a weekend house and they wanted their primary residence to be close to the F.D.R. so they could get out of town quickly for the sake of the dog, because otherwise he would get very stressed,” said Barbara J. Dervan, an associate broker at Fox Residential Group. The solution: an apartment on East End Avenue.

“Not all clients who have pets are intense,” Ms. Dervan added. “But over the last five to eight years, even people who don’t have pets have shied away from buildings with a no-pet policy. It takes away the option of buyers to change their mind about pet ownership in the future. And when they go to resell their apartment there are fewer people willing to look at it.”

Some newly developed condos and rentals have been responding to the pet-possessed with far more than a pet-friendly policy. There are on-site day care and dog-walking services and grooming stations. Such amenities were partly what inspired Bert Saville to rent at MiMA, a mixed-use high-rise in Hell’s Kitchen.

Three years ago, when Mr. Saville, 39, a marketing manager at Pernod Ricard U.S.A., the wine and spirits company, moved to New York from Miami, he knew what he wanted: a walk-up, preferably in a brownstone; failing that, an apartment on a high floor with a grand view of the city. Dreams, dreams, idle dreams. None of this was going to work for Wesley, Mr. Saville’s harlequin Great Dane. Climbing stairs would have been tough on Wesley’s legs, so an elevator building was a must. But an apartment high in the sky, Mr. Saville’s preference, wouldn’t have served Wesley’s needs, either.

“I wouldn’t say I’m ruled by my dog, but I have to give up a certain number of things because of him,” Mr. Saville said. Despite his own preferences for an eyeful of cityscape and sky, he looked for a vacancy on the lowest floor available.