Food and Agricultural Code § 31642
ARTICLE 3. Disposition of Potentially Dangerous or Vicious Dogs
A potentially dangerous dog, while on the owner’s property, shall, at all times, be kept indoors, or in a securely fenced yard from which the dog cannot escape, and into which children cannot trespass. A potentially dangerous animal may be off the owner’s premises only if it is restrained by a substantial leash, of appropriate length, and if it is under the control of a responsible adult.