(a) A trainer shall be responsible at all times for the condition of all horses trained by him or her. No trainer shall start or permit a horse in his or her custody, care or control to be started if such trainer knows, or might have known cause to believe, that the horse has received any drug or other restricted substance that could result in a positive test. The trainer shall be held responsible for any positive test unless such trainer can show by substantial evidence that neither such trainer nor any employee nor agent was responsible for the administration of the drug or other restricted substance. Every trainer must guard each horse trained by him or her in such manner and for such period of time prior to racing the horse so as to prevent any person whether or not employed by or connected with the owner or trainer from administering any drug or other restricted substance to such horse contrary to this Part.

(b) Trainers shall maintain accurate records of all corticosteroid joint injections to horses trained by them. The record(s) of every corticosteroid joint injection shall be submitted, in a form and manner approved by the commission, by the trainer to the commission within 48 hours of the treatment. The trainer may delegate this responsibility to the treating veterinarian, who shall make these reports when so designated. The reports shall be accessible to the examining veterinarian for the purposes of assisting with pre-race veterinary examinations.