Dressage rider Isabell Werth has been embroiled in a legal battle with the German Equestrian Federation since last fall, when the Olympian received a six-month competition ban and a €2,000 fine, stemming from a June 2012 positive drug test in one of her mounts.

Werth’s horse, El Santo NRW, tested positive for cimetidine at the 2012 Rhineland Championships. The drug, which is used to treat stomach ulcers, is not banned by the FEI, but is on the German Equestrian Federation’s forbidden substances and prohibited medication in competition list.

Recently, a major sponsor of the international German equestrian teams, AGCO/Fendt, urged the German Equestrian Federation to lift the suspension, as they support Werth’s claim that the horse was accidentally contaminated with the drug through a faulty watering system.

On March 17th, the Court of Arbitration for Sport (CAS) acknowledged that a minor violation had occurred in this case, and upheld the fine, plus legal costs, but reinstated Werth’s right to compete. Werth told reporters she was relieved and called for harmonization between national and international medication rules.