German dressage rider Isabell Werth is meeting her fair share of battles in 2013. In addition to facing possible sanctions for prohibited substances, the five-time Olympic gold medalist is also contending with public fire over hyperflexion.

Werth’s 11-year-old Rhinelander gelding El Santo tested positive for cimetidine, a prohibited substance in the rules of the German Equestrian Federation (FN), at a national competition last June, a spokesperson for the FN said. Cimetidine is a drug used for treating or preventing digestive tract ulcers.

"It’s possible that this was an unintentional ingestion of the medication through a technical problem in the stall, and Isabell Werth must prove that to the German federation through analyses and testing," FN spokesperson Susanne Hennig told The Horse. "Theoretically if she can prove her innocence, then there will be no sanctions."

El Santo’s stall neighbor Warum Nicht FRH–Werth’s mount at the 2010 World Equestrian Games, held in Lexington, Ky.–was being treated with cimetidine to prevent stomach upset after a prolonged treatment with pain medicine following a fracture, according to a spokesperson for Werth. Werth suspects that El Santo might have accidentally consumed some of the medication due to the close proximity of the horses, the spokesperson said. Currently all sorts of potential contamination are being examined