Cal. Code Regs. tit. 18, § 1046
(b) In order to qualify as a racehorse a horse must be registered or eligible to be registered with an agency recognized by the California Horse Racing Board. Agencies currently recognized are as follows:
Agency
Breed
The Jockey Club
Thoroughbred
The American Quarter Horse Association
Quarter Horse
The United States Trotting Association
Standardbred
The Appaloosa Horse Club
Appaloosa Horse
The Arabian Horse Registry of America
Arabian Horse
A horse over three years of age, or over four years of age in the case of an Arabian horse, that, in the two previous calendar years, has neither participated in a horserace contest on which parimutuel wagering is permitted nor been used for breeding purposes in order to produce a racehorse eligible to participate in a horse race contest on which parimutuel wagering is permitted is not a racehorse within the meaning of part 12 of division 1 of the Revenue and Taxation Code. Any such horse is subject to ad valorem taxation unless otherwise exempt.
Note: Authority cited: Section 15606, Government Code; and Section 5781, Revenue and Taxation Code. Reference: Sections 5703, 5710, 5711 and Part 12, Division 1, Revenue and Taxation Code; and Sections 19409, 19413.5, 19416, 19416.5 and 19416.7, Business and Professions Code.
1. New section filed 11-1-72; effective thirtieth day thereafter (Register 72, No. 45).
2. Amendment to subsection (b) filed 5-2-74; effective thirtieth day thereafter (Register 74, No. 18).
3. Amendment filed 8-27-87; operative 9-26-87 (Register 87, No. 35).