You'll see balms and creams advertised everywhere, replete with the magical ingredient capsaicin. It's what makes hot peppers hot, and it's supposed to be great for relieving arthritis pain and soothing sore muscles. It's also banned in the Olympics.
Horses have their own brands of pain-relieving ointments containing capsaicin, and Denis Lynch made the mistake of using it on his horse. He didn't think twice about rubbing a bit of Equi-Block on Lantinus. It's not a product requiring a prescription or a vet's approval.
A horse jumping in Olympic competition is an athlete, and is subject to the same doping tests. The lab in Hong Kong discovered capsaicin in Lantinus' samples, and so Tipperary native Denis Lynch was disqualified from the competition.
Capsaicin works the same in horses as in people, but when it's a champion jumper that's getting pain relief, it's not allowed. A showjumper that isn't feeling a twinge would jump a bit better, hence the performance would be enhanced and performance enhancement is strictly forbidden for all athletes competing in the Olympic Games.
You'd think that after the Athens Olympics, when Cian O'Connor lost his gold medal because his horse turned up with traces of banned substances, that Ireland's riders would be doubly cautious. However, the Irish horse wasn't alone in showing traces of capsaicin. Brazil, Germany and Norway also had riders tossed out.
Mr. Lynch faces a long-term ban from showjumping, unless he can convince the ruling body that he wasn't cheating, but was merely rubbing his horse with the sort of cream that any desk jockey would apply after a weekend of yard work. The equestrian federation will have to decide if this is a new angle to get horses to lift their legs higher, or if riders were only tending to their horses with loving care.