The stewards may declare a horse out of a race when in the opinion of the Official Veterinarian or the Racing Veterinarian such horse cannot give his best efforts to win such race due to physical disability or other physical cause. The further entry to any race in this State of such horse shall not be accepted until the expiration of at least 48 hours from the time of declaration and until the said horse has been examined, and his physical condition approved for racing by the Official Veterinarian.
Cal. Code Regs. Tit. 4, § 1628