SACRAMENTO — The Legislature's customary agenda of healthcare, education, public safety and other human affairs was interrupted today by this year's issue that mattered most to the masses: the sex lives of dogs and cats.

The Capitol doors opened extra early, an overflow room was provided to accommodate spectators and extra security was on hand for an 8 a.m. committee hearing that would determine the fate of AB1684 — a bill supporters called the California Healthy Pets Act, and opponents labeled the Pet Extinction Act.

In the end, the bill was put on hold until next year. The bill's author, Assemblyman Lloyd Levine, D-Van Nuys, made the decision after it became apparent that members of the Senate Local Government Committee were prepared to vote it down.

The bill called for the mandatory spaying or neutering of all dogs and cats, with certain exceptions for breeders of purebreds, police dogs, guide dogs for the disabled and for everyday pet owners who simply wanted the family pet to produce just one litter before being sterilized.

The list of organizations supporting the bill ran 10 pages, from the Alpha Canine Society to Underdog Rescue. The list of opponents was nine pages long, from the Airedale Terrier Club of America to the Yorkshire Terrier Club of Los Angeles. Opponents also weighed in with petitions containing 10,000 signatures and enough faxes to break the committee chairwoman's fax machine.

In the two days leading to the hearing, the bill had brought TV celebrity Bob Barker to the Capitol to lobby on its behalf, followed by a protest appearance by a descendant of TV's Lassie and the actor who played Timmy, Jon Provost, the dog's faithful companion.

In the end, Lassie won the day.

William Hemby, lobbyist for a pet owners' group called PetPac, attributed the bill's defeat to a true grassroots uprising the likes of which he's never seen in 30 years as a lobbyist.

"We put together thousands and thousands of pet owners," Hemby said. "It's never been done before in the history of the state."

He said they were motivated by the fear that such a law, if aggressively enforced, could have dried up the supply of puppies and kittens and ended pet ownership as it exists today.

"Our members were equating this to Prohibition," he said. "People just don't like to be told what to do with their dogs and cats."

Levine argued that, thanks to education and the proliferation of low-cost spay and neuter clinics, 70 percent of pets in California today are sterile. He said only a mandate could reach the remaining 30 percent and thus relieve the financial and emotional burden of having to exterminate tens of thousands of unwanted cats and dogs each year.

Barker, who spoke at a Capitol news conference Monday to promote the bill, said a mandate will be needed if California is to end the suffering and slaughter.

"Our country, if it's to be civilized, must protect all living things," he said.