san francisco california may become the only us state to require the sterilisation of pets under a bill passed by the state assembly pitting dog and cat lovers against animal rights activistsits a horrific bill said maureen hillhauch executive director of castleton new yorkbased american dog owners association adding that enforcement of the bill in theory could wipe out californias dog populationthe bill would require pet owners to spay and neuter their dogs and cats or face a 500 fine for each animalbreeders as well as owners of guide dogs could obtain exemptionsthe democratled state assembly narrowly approved the bill late on wednesday it now goes to the state senate amid a flurry of legislation that must be passed by friday