NEW YORK » Four days before previews, the cast and crew of the new Broadway version of "Breakfast at Tiffany’s" were putting the finishing touches on the show’s blocking, lighting and costumes. But on this final day of February, there remained one gaping hole: The director still hadn’t cast the role of Holly Golightly’s cat.

It is not, thankfully, a speaking role. But the requirements are stiff. Just as Holly’s cat plays a key part in the Truman Capote novella, it does in this new Richard Greenberg adaptation. It must be handed from one actor to another, sit during a party scene as Holly explains that it is nameless because it doesn’t belong to anyone, and walk offstage. Near the end, saying they are both independents who never made each other any promises, Holly tosses it onto a city street, and the cat must run into the wings.

So the role requires not only an animal that can handle lights, microphones and an audience, but also one that can cross the stage, sit, stay and exit on cue. In short, it requires a dog.

The 1961 film version of "Breakfast at Tiffany’s," with its star turn by Audrey Hepburn as a New York party girl, may be part of the Library of Congress’ National Film Registry, but stage productions haven’t proved as memorable. A 1966 musical was pulled during previews when the producer David Merrick decided it was "excruciatingly boring." The director of this version, Sean Mathias, oversaw a different adaptation in London in 2009 that received middling reviews. And in January a major investor pulled out of this production, but producers wooed him back, and the show will go on, with its opening night on March 20, assuming that the cat will go on.

If audiences coo when an animal appears onstage, directors groan. Even trained animals still react like, well, animals. Bill Berloni, an animal trainer who cast the dog Sandy in the current Broadway production of "Annie," remembers when a family in the front rows of "Legally Blonde: The Musical" brought a bucket of chicken, and the Chihuahua he had cast abandoned his role to hover at the edge of the stage. And last-minute changes complicate matters even more: When the Radio City Christmas show used a new musical cue during a scene with donkeys, "the donkeys were trying to lead their actors offstage when the music changed, and they couldn’t understand why they weren’t allowed to leave," said Babette Corelli, the donkeys’ animal trainer.

With "Breakfast at Tiffany’s," the bigger headache is that it’s not any animal, it’s a cat. While dogs have been bred to obey and please humans, cats are independent and don’t train as well, Berloni said. Having a cat in a play can mean designing the action around it, "as opposed to going, ‘The cat has to walk to center stage and do something,’ because cats don’t do that," he said.

An earlier open call for the cat in "Breakfast at Tiffany’s" brought in 100 submissions, and eight cats auditioned live. But Corelli, who is training cats for the show, said they were "amateur" cats. A few fled the stage in terror, and the rest didn’t learn commands quickly enough, so Corelli called in two pros: One of her own cats, a skinny, inquisitive black-and-white male named Montie, would go up against Vito Vincent, a plump ginger-colored male whose card lists him as "Talent."

Corelli helps run Dawn Animal Agency, an animal-casting company with a 300-acre animal sanctuary in New York’s Hudson Valley filled with cats, dogs, rats, camels, birds and more. Almost all of her 90 or so cats are rescues, and she chooses the ones for acting work based on whether they are confident, sensible and aren’t bothered by noises or people, and then determines what rewards they want (food, toys, or, occasionally, affection).

Leading up to Vito and Montie’s auditions, Corelli used a clicker, verbal commands and hand signals to teach the cats the role. When they arrived at the theater, she let each one explore the stage to get used to the smell and dimensions. Their dressing room was in between George Wendt’s, who plays Joe Bell, the local bartender, and Cory Michael Smith’s, who plays Fred, Holly’s neighbor, sparring partner and admirer. It was stocked with well water from the farm for Montie, and for Vito, a framed photo of himself "so he had a little bit of home," said his owner and handler, Michael LeCrichia.

By midweek, Montie and Vito were in the show-business whirl. In a suite at the Carlyle during a press event, Vito was sacked out by the windowsill, while Montie rooted through Corelli’s bag for snacks. When the time for a photo op came, the cats sauntered down the hall with their trainers as Corelli got sidelined by a blogger for Fancy Feast cat food.

The cats’ second rehearsal of the party scene occurred the next day, this time at the show’s home, the Cort Theater. But, unknown to Corelli, the director had changed some of the blocking, from the fire escape the cats had rehearsed on before to inside Holly’s apartment, stacked with suitcases. With no time to check out the new set, Vito and Montie were going in cold.

The director, Mathias, was onstage, waiting for Smith to join the show’s Holly, Emilia Clarke, for the scene. "Let’s bring the cats while we wait," said Mathias, who’s worked with felines in the London version of "Breakfast at Tiffany’s." Vito went first, carried out by an actor playing Holly’s suitor Rusty, who passed him to Clarke.

"Let’s try the new move with the suitcase," Mathias said, and Clarke turned and tried to hold on to Vito as she sank onto the suitcases. But Vito fidgeted. "Chill, Vito," Mathias said.

Clarke continued: "Poor slob without a name."

"Come upstage and set him down," Mathias instructed, but Vito leapt out of Clarke’s arms before she could. "Don’t throw him!" Mathias said.

Corelli sidled onstage. "I’ll make sure to send the cat out facing this direction so he has his face to the audience, not his butt," she said. LeCrichia then suggested that Clarke perch Vito on the stack of suitcases for the speech, rather than holding him. "You can just put him on the suitcase like that? Mathias said. "That’s great."

They tried again, but this time Vito ended the scene by wandering toward the lip of the stage. Though LeCrichia was in the second wing, where Vito was supposed to exit, the lights were too bright for Vito to see him, Corelli explained later, so LeCrichia would need to be louder.

Smith joined Clarke on the stage for a full run-through. It was Montie’s turn now, but a few moments into the scene, he jumped out of Rusty’s arms and scurried offstage. "Montie’s no good — it’s not going to work," Mathias said. (Corelli remains a Montie supporter, and will train him and three other cats as understudies.)

"We need to rehearse Vito one more time," a loudspeaker boomed.

"This is not about rehearsing the cats," Mathias muttered to an associate.

With minutes left before they had to move on to the next scene, Vito was given a final try. The handoff from Rusty was clean, and Clarke placed Vito on the suitcase as she sat. Although Vito leapt off the suitcase, Smith, reacting fast, knelt down to scratch the cat’s head as he delivered his lines, then plucked him from the floor and gave him back to Clarke. It wasn’t perfect, but it was close enough for a cat.

"And cut. Vito’s a star!" Mathias said. "Moving on."