(a) Before sending a specimen from a horse to a testing laboratory, the commission veterinarian shall determine whether the specimen is of sufficient quantity to be split. If there is sufficient quantity, the commission veterinarian or the commission veterinarian's designee shall divide the specimen into two parts, and both parts will be shipped to the testing laboratory for testing and storage for future testing, if applicable. If the specimen is of insufficient quantity to be split, the commission veterinarian may require the horse to be detained until an adequate amount of urine can be obtained. If the commission veterinarian ultimately determines the quantity of the specimen obtained is insufficient to be split, the commission veterinarian shall certify that fact in writing and submit the entire specimen to the laboratory for testing.(b) An owner or trainer of a horse which has received a positive result on a drug test may request, in writing, that the split of the specimen for the primary sample with the positive result, be submitted for testing by a different technician at a Commission approved testing laboratory of the owner or trainer's choice if available. The owner or trainer must notify the executive director of the request not later than 48 hours after notice of the positive result. Failure to request the split within the prescribed time period will be deemed a waiver of the right to the split specimen.(c) If the test on the split specimen confirms the findings of the original laboratory, it is a prima facie violation of the applicable provisions of the chapter.(d) If the test on the split specimen portion does not substantially confirm the findings of the original laboratory, the stewards may not take disciplinary action regarding the original test results.(e) If an act of God, power failure, accident, labor strike, or any other event, beyond the control of the Commission, prevents the split from being tested, the findings of the original laboratory are prima facie evidence of the condition of the horse at the time of the race.