LOS ANGELES -- A plan to crack down on pit bulls and Rottweilers -- aimed at reducing the number of dog attacks -- has mushroomed into a far more sweeping proposal that would require the spaying or neutering of most dogs in unincorporated areas of Los Angeles County.
About 1 million residents could be affected by the ordinance, which supervisors expect to revisit next month.
Other cities and counties around the nation are adopting similar measures, but few appear to be as broad as the one proposed by Mike Antonovich, county supervisor.
Although recent state legislation allows local governments to require spaying and neutering for some breeds, county animal control officials said they decided to push for a broader measure, in part because of complaints from pit bull and Rottweiler owners that it would be unfair to single out their dogs.
But officials also saw the rewrite of the proposed ordinance as an opportunity to help stem the problem of pet overpopulation.
''We still get other dogs in. We get way too many," said Marcia Mayeda, director of the county Department of Animal Care and Control who is working on the proposal. ''There was a point to be made. Why not all breeds? Why don't we include everybody?"
Last year, Mayeda said, nearly 20,000 dogs were put to death in the county's overcrowded animal shelters.
Most other jurisdictions that restrict dog ownership single out breeds considered dangerous.
In January, San Francisco made it illegal to own an unsterilized pit bull or pit bull mix. Denver outlawed pit bulls altogether in 2005. Animal control officials in the city of Los Angeles also are considering whether to propose spaying and neutering requirements for all dogs -- and perhaps for cats as well.
After a 10-month-old girl in his district was bitten in the face by a pit bull on Jan. 23, Antonovich asked county officials to come up with an ordinance that would address what he called a ''serious public safety threat." Pit bulls and Rottweilers were the ones responsible for the majority of attacks, he said.
But owners of those breeds disagreed and said the plan would perpetuate the stereotype that their dogs are dangerous. More than 50 dog owners, most of whom had pit bulls or Rottweilers, attended a recent Board of Supervisors meeting and protested the breed-specific proposal.
''It is not the breed that is the problem," Wendy Ruben, who runs a rescue kennel in Palmdale, north of Los Angeles, said at the meeting. She said a French woman who received the world's first face transplant last year had been mauled by a Labrador retriever.
Susan Taylor, executive director of Actors and Others for Animals, said that what officials may ''find wrong with one breed today will be another breed tomorrow."
''It really isn't the breed, it's the dog," she said in support of the revised proposal that would affect all dogs. The goal of her organization, founded in 1971, is to curb overpopulation by subsidizing spaying and neutering.
Mayeda said she had first suggested a breed-specific measure because pit bulls and Rottweilers were overrepresented in the county's six animal shelters.
''We selected those two breeds because they would decrease euthanasia in our shelters," she said.
But after meeting with pit bull and Rottweiler owners, she recommended that the county broaden the measure to include nearly all dogs.
The county charges $15 to license an altered dog and $30 for one that has not been spayed or neutered. Under the new proposal, which is still being drafted, a license for an unaltered dog could cost $150.
Under the proposed measure, only dogs that were purebred, registered, and equipped with an identifying microchip could remain unaltered.
They also would need to pass health and temperament tests. Officials would inspect the owners' houses to ensure that the premises are suitable for breeding.
Mayeda said she expects that most of the people who will apply for unaltered-dog licenses would be breeders and those who enter their pets in competitions. But some of these people aren't happy with the proposal.
''We ask that there be additional statutes in the ordinance for show dogs, so that we can continue to do what we do without being penalized," said Jeremy Schuster, who competes with his Rottweiler. ''A show dog is not likely to be a part of the shelter populace."
The American Kennel Club, which maintains a purebred dog registry and holds dog events around the country, opposes mandatory spaying or neutering of dogs.
Instead, the group supports better enforcement of laws against dangerous dogs, including increased fines or jail time, that are already on the books, according to spokeswoman Daisy Okas.