California Code, Revenue and Taxation Code - RTC § 5765

(a) The assessor may perform audits of the books and records of any owner of racehorses subject to the tax imposed by this part in the county to determine if the correct information has been reported and the proper amount of tax has been paid.

(b) In those cases wherein the board determines that an audit would have been required under Section 469 if the racehorses were subject to property taxation, rather than to the provisions of this part, the assessor shall perform such audits of the books and records of the owners of racehorses subject to the tax imposed by this part as the board by rules and regulations may prescribe.