South San Francisco, CA Animal Ordinances: Cat Rules (2026)

Cats in unincorporated San Mateo County are regulated under the County Ordinance Code, Title 6. PHS/SPCA, the County's contracted animal control provider, states that all dogs and cats over three months of age must be licensed and have a current rabies vaccination, with new residents allowed 60 days to comply. Chapter 6.12 (Spaying, Neutering and Breeding) adds a spay/neuter requirement: a person who owns or harbors within unincorporated San Mateo County any cat or dog over six months of age that has not been spayed or neutered must obtain either a license to keep an unaltered animal or a license and permit for breeding. This means an unaltered cat must be specifically licensed or permitted, encouraging sterilization. Unlike the dog rules, the County Ordinance Code does not impose a general cat-leash or confinement mandate equivalent to the dog leash law in Section 6.04.070, so cats are not required to be leashed; however, the animal-care standard in Section 6.04.070(d) (proper and adequate food, water, shelter, care, and attention) and the pet-limit and animal-fancier permit tiers still apply to cats. Owners of cats should keep rabies vaccinations and licensing current and, if keeping multiple cats, observe the animal fanciers permit threshold (up to ten) and the kennel/cattery permit threshold (more than ten).