BELOW THE $75-per-night penthouse of Sniff Dog Hotel, in the archetypal neighborhood known simply as Northwest, humans have formed an important new bond around a shiny bar/café next to the K9-grass-carpeted playroom for their pets. On a recent evening, two business-clad women sat on the sidewalk patio, sipping chardonnay. A black Labrador reclined beneath their table, dining on a grass-fed-beef Bully Stick.

Inside, Match.com first-daters strived for common ground, while more established couples quietly drank beer and tapped on laptops. On the other side of the plate-glass window, a large sheepdog bounded about while a docile dachshund watched from its perch on a raised dog bed.

A bartender reported that wilder moments on the other side of the glass produce an echo effect in the café: “Everyone will be like, ‘Whose dog is that?’ Then strangers will start talking. Next thing you know, people are dating.” So far, the most notable romantic success involves the owners of a Bernese mix and a pointer.

Meanwhile, cliques have begun to form. A group of about five couples, for instance, gathers around a chosen table once a week. A few weeks ago, it seems they took matters beyond Sniff when they met for a hike. No word on how they chose a leader of the pack.

Sniff Dog Hotel’s bar/café offers complimentary doggy day care with a two-drink minimum, 5–7 p.m. Mon–Sat.