What must be done if any changes in ownership or trainers occur after registration papers have been submitted?

When there are changes in ownership or trainers after registration papers have been submitted, it is essential to report those changes to the steward's office. This requirement ensures that all stakeholders have up-to-date information about the horses and individuals involved in races, maintaining transparency and compliance with racing regulations.

Reporting changes to the steward's office facilitates proper oversight of the race participants and helps protect the integrity of the racing industry. The stewards are responsible for enforcing the rules and regulations of the racetrack and ensuring that all changes are documented and acknowledged, which is critical for both the safety and fairness of racing.

Other options would not adequately address the necessary protocol following a change in ownership or trainers. Failing to report could lead to issues concerning eligibility or disputes regarding the ownership or responsibilities of the horse, which could negatively impact the racing events and associated operations.