By Caroline Stauffer

SAO PAULO (Reuters) - In a sport long dominated by Europeans, South American riders will be out in force at the continent's first Olympic Games to be held in Rio de Janeiro's Deodoro area next month.

Argentina, Colombia, Venezuela, Uruguay and hosts Brazil are all represented. Peru qualified for the individual show jumping competition for the first time, as did Ecuador in individual three-day eventing.

"It's more than the usual... The level has increased tremendously so they are a force to contend with in the future," Sabrina Ibanez, secretary general of the International Equestrian Federation (FEI), said of South American riders.

Ibanez told Reuters more South Americans had qualified after investment in grass-roots development programs over the past decade. She noted a strong showing in last year's Pan American Games in Toronto, where Venezuela claimed silver in individual jumping and Argentina came second in team jumping to Canada.

Riders from Chinese Taipei, the Dominican Republic, Palestine, Qatar and Zimbabwe will also be making Olympic debuts, though the favorites are coming from more traditional equestrian strongholds like Germany and Great Britain.

At the 2012 Olympics in London, New Zealand and Saudi Arabia were the only non-European countries to take home equestrian medals - bronze for team eventing and team show jumping respectively.

In addition to the geographical diversity, much of the 2016 equestrian field is young. The entire Brazil dressage team is under 25.

With a new generation coming up, some notable veterans were left out. Brazil's only Olympic gold medal equestrian, the 2012 flag bearer Rodrigo Pessoa, is the alternate of the host nation's show jumping team.

Canada's Ian Millar, who holds the record for most Olympic appearances at 10 Games, has been sidelined due to an injured horse but his daughter Amy will make her show jumping debut.

Among the Olympic champions returning are Germany's four-time gold medal list Ludger Beerbaum, 52, in show jumping and New Zealand's double gold medalist Mark Todd, 60, in eventing.

"The level of competition is so strong at the moment and you just need everything... it could go to any one of 10 different people and hopefully I might be one of those 10," Todd, who heads to Rio with more Olympic medals than any other equestrian, told Reuters.

Germany's Michael Jung is returning after winning team and individual gold in eventing in London and Great Britain's dressage prodigy Charlotte Dujardin is back with Valegro, the horse she won individual and team gold medals on in 2012.

Athletes and the FEI, the sport's governing body, said they were pleased with the Deodoro facility, which has been upgraded since hosting the Panamerican Games in 2007.

An episode of Glanders, a fatal disease for horses, at a nearby military facility is no longer a concern after Deodoro was isolated for much of last year, Ibanez said.

"The agriculture ministry has guaranteed that the place is clean, they have done all tests necessary so we are confident it is completely free," she said.

(Additional reporting by Alan Baldwin; Editing by Ken Ferris)