Belgian endurance rider Evelyne Stoffel has been given a 15-month suspension and been handed a fine by the FEI Tribunal.

Her horse Houkoumi G tested positive for the opioid analgesic O-Desmethyl-Tramadol at a race in Virton on September 4, 2015.

A decision was also taken to give Mexican showjumper Andres Arozarena a six-month suspension, following a positive test for his horse La Petite Fleur 6.

Having competed in Coapexpan on October 14, the horse tested positive for the anti-inflammatory piroxicam.

With Arozarena having already begun a provisional suspension on December 20, it was credited against his period of ineligibility.

His suspension therefore ran until June 19, with Arozarena now free to return to competition.

He was also made to pay a fine following the case.

The third case involved the horse Felix Van De Mispelaere, which tested positive for the vasodilator minoxidil, which can be used to lower blood pressure.

The horse tested positive at a competition in Polokwane on August 29, 2015, when ridden by South Africa’s Jonathan Clarke.

Clarke had been provisionally suspended from October 21 of the same year to May 18, 2016.

The FEI Tribunal ruled that Clarke did not bear any fault for the rule violation, with a decision made to not give a further period of suspension.

It was argued that the positive test had occurred as a result of contamination, with the horses’ owner Mark Slade claiming he used minoxidil to help regrow hair.

Slade claimed the substance may have entered the horse’s system through barley grass, which may have been transferred following his personal use.

“The Tribunal follows the FEI submission, and finds that the PR could not have suspected or reasonably have known, even with the exercise of utmost caution, that the product used by Mr Slade – of which he had no knowledge – could have contaminated either the barely grass or potentially also the urine sample.

“As a consequence, the Tribunal finds that the person responsible bore no fault for the rule violation.”

The athletes have been given 21 days to appeal decisions to the Court of Arbitration for Sport from the date of notification of the decisions.