Should a horse leave the course while moving from the paddock to starting gate, it shall return to the course at the nearest practical point to that at which it left the course and shall complete its parade to the starting gate from the point at which it left the course. However, should such horse leave the course to the extent that it is out of the direct line of sight of the Stewards, or if such horse cannot be returned to the course within a reasonable amount of time, the Stewards shall scratch the horse. Any horse which leaves the course or loses its Jockey during the running of a race shall be disqualified and may be placed last, or the horse may be unplaced.
Okla. Admin. Code § 325:60-1-18