By KATE TAYLOR

The mayoral candidates participating in a forum on Monday on animal rights all did their best, in various ways, to prove themselves animal lovers. But when it came to over-the-top stories of devotion, none of them outdid John A. Catsimatidis, the businessman and Republican candidate, who described how he once called the Fire Department to rescue his daughter’s escaped cockatiel, and how his wife tried to save the life of the family’s elderly cat by giving it mouth-to-mouth resuscitation. (The cat did not survive.)

Animal rights have emerged recently as an unexpected tinderbox in the mayoral race, primarily around the issue of New York’s horse carriages. Efforts to ban the industry, which some consider inhumane, have been opposed by Christine C. Quinn, the City Council speaker and Democratic mayoral candidate, making her a bête noire of animal rights activists. Recently, Steve Nislick, a parking garage magnate and the founder of a group that is dedicated to banning the carriages, helped pay for a series of ads attacking Ms. Quinn.

So it was little surprise that when Mr. Nislick’s group, Nyclass, announced that it was hosting a forum on animal rights, Ms. Quinn did not attend. Even so, her name was invoked frequently. Before the forum began, the executive director of the group, Allie Feldman, asked audience members to take out their cellphones and call her office to protest her stance on the carriage industry.

“There is one thing I think that just about everybody in this room can agree on,” Ms. Feldman said. “That is that Christine Quinn has not been a friend to animals.”

A spokesman for Ms. Quinn, Michael Morey, said Monday night that Ms. Quinn had a strong record on animal rights, including expanding financing for spaying and neutering programs, increasing safety measures for kennels and passing laws cracking down on animal abuse.

The moderator, Tom F. Allon, who recently gave up his campaign for the Republican nomination, asked the candidates whether they would support legislation requiring sprinklers in pet stores, and how they would manage New York’s goose population. But the emotional heart of the evening, for the audience, was the carriage issue.

Mr. de Blasio, the public advocate, drew thunderous applause and foot-stomping for his declaration, “The time for an end to horse carriages is now.”

John C. Liu, the comptroller, said he supported a pilot program to replace carriages withelectric cars, as Mr. Nislick’s group has proposed. He also tried to goad Mr. de Blasio, who he said had only recently come to oppose the carriage industry. After he noted that in the past Mr. de Blasio had voted to reform, but not ban, the industry, Mr. de Blasio erupted in irritation.

“John, I admire your debate technique,” he snapped dismissively. Both Mr. Thompson, a Democrat and former comptroller, and Mr. Albanese, a Democrat and former city councilman, said that they supported phasing out horse carriages but that they were concerned about the jobs of those in the industry.

In contrast, Mr. Catsimatidis said without apology that he liked the horse carriages. He said they contributed to the “ambience” of Central Park.

When the audience booed and hissed, Mr. Catsimatidis entreated them to let him finish. He suggested, among other things, that retired carriage horses could be housed at the Central Park Zoo. When the audience hooted with derision, he shrugged and said: “It’s only a suggestion.”

“I love the animals,” he continued, “and I think they should be well treated.”