(a) Except as otherwise provided by this section, an occupational licensee may not, while performing duties required of the licensee, have present in his or her system a dangerous drug as defined by the Health and Safety Code, Chapter 483, or a controlled substance as defined by the Texas Controlled Substances Act, Health and Safety Code, Chapter 481. The Commission, stewards, or racing judges may decline to take disciplinary action against a licensee who violates this subsection if the Commission, stewards, or racing judges determine that:(1) the licensee holds a current prescription for the drug or substance, which was issued by a physician licensed to practice in the United States and authorized to dispense or prescribe controlled substances as provided by 21 USC 801 et seq. and the physician is acting in the course of the physician's professional practice;(2) the drug or substance was prescribed to the licensee for a legitimate medical use; and(3) the use of the drug or substance will not impair the licensee's judgment, reaction time, or physical abilities as they relate to the licensee's performance of his or her duties.(b) An occupational licensee may not possess, while on association grounds, a dangerous drug as defined by the Health and Safety Code, Chapter 483, or a controlled substance as defined by the Texas Controlled Substances Act, Health and Safety Code, Chapter 481. This subsection does not apply to:(1) a licensee who holds a current prescription for the drug or substance, which was issued by a physician licensed to practice in the United States and authorized to dispense or prescribe controlled substances as provided by 21 USC 801 et seq. and the physician is acting in the course of the physician's professional practice; or(2) a veterinarian licensed by the Commission who has obtained permission to possess a controlled substance or dangerous drug under §319.14 of this title (relating to Possession of Controlled Substances).