Contra Costa County, CA Animal Ordinances: Breed Restrictions (2026)

Under § 416-12.402 (now codified in Chapter 416-18 after a 2020 amendment), an animal is 'potentially dangerous' if, on two separate occasions within 36 months and off the owner's property, it engages in unprovoked behavior requiring defensive action, or if it bites unprovoked causing a minor injury, kills or seriously injures a domestic animal off the property, or otherwise constitutes a physical threat. An animal becomes 'dangerous' under § 416-12.404 when it inflicts severe injury or kills a peaceful person unprovoked, has already been designated potentially dangerous and reoffends, is associated with a Penal Code § 597.5(a) conviction, or attacks livestock off the owner's property. These definitions are behavior-based and explicitly breed-neutral. California state law (Food & Agric. Code § 31683) further bars cities and counties from enacting breed-specific bans on dog ownership, though spay/neuter requirements targeting a breed are permitted. In 1985 Contra Costa considered and rejected breed-specific legislation in favor of the generic dangerous-dog framework that remains in effect.