The Court of Arbitration for Sport (CAS) upheld the Fédération Equestre Internationale (FEI)’s policy of imposing two-month provisional suspensions on horses that test positive for banned substances under its Equine Anti-Doping Regulations.

The ruling came as part of an appeal filed by U.S. dressage athletes Adrienne Lyle and Kaitlin Blythe after two-month provisional suspensions were imposed on their horses, Horizon and Don Principe, on April 5, 2017. Samples taken from the horses at an international dressage event in Florida in February 2017 returned positive for the banned substance ractopamine, a beta adrenoceptor agonist which, according to the FEI Equine Prohibited Substance Database, has been shown to improve growth in pigs; it is not approved for use in equids. The FEI also provisionally suspended the two athletes, but lifted those suspensions.

The FEI Tribunal denied an application to lift the horses’ provisional suspensions, however. In May 2017, Lyle and Blythe obtained an CAS interim decision pending the full hearing of their appeal, which cleared the horses to compete again.

The CAS heard the full hearing on the riders’ appeal against the equine provisional suspensions in November 2017 and issued its final decision on March 19. The CAS confirmed the validity of the FEI’s policy of two-month equine provisional suspensions in banned substance cases. The three-person CAS panel held that the federation created the policy “in pursuit of a legitimate aim” and has “a consensus of approval in the equine community