Cal. Food and Agricultural Code - FAC § 30951. Section 30951.
It is unlawful for any person to own, harbor, or keep any dog over the age of four months, or to permit such a dog which is owned, harbored, or controlled by him to run at large, unless the dog has attached to its neck or leg a substantial collar on which one of the following is fastened:
(a)
A metallic tag which gives the name and post office address of the owner.
(b)
A metal license tag which is issued by the authority of a county, city and county, or any municipal corporation for the purpose of identifying the dog and designating the owner.
