Food and Agricultural Code § 31765
CHAPTER 2. Special Provisions Applicable to Counties With a Population of Less Than 100,000 Persons
Whenever a county, or a city that is within a county to which this chapter applies, requires cat license tags, the tag shall be issued for one-half or less of the fee required for a cat, if a certificate is presented from a licensed veterinarian that the cat has been spayed or neutered.