FEI President Princess Haya of Jordan described the support as "a true landmark moment in the history of our sport."

Princess Haya commissioned a review after six horses tested positive for banned drugs at last year's Beijing Olympics.

She has led a modernizing campaign since being elected president in 2006, two years after three gold medals were taken from riders involved in doping at the Athens Games.

"This vote has given us the power to roll out (the review) and allow us to restore the public image of our sport as a clean and uncorrupt product," she said in a statement.

National associations voted 90 to 8 at their general assembly in favor of measures to crack down on teams and riders doping horses. The FEI will employ an independent investigations unit and step up stables security at top events.

They also voted 95-5 for rules controlling the use of certain medications. More than 1,000 drugs now feature on a prohibited list revised each year.

Riders had argued for better guidance on using some drugs that are banned in competition but can be used in training.

The new program was shaped by research led by Arne Ljungqvist, vice president of the World Anti-Doping Agency, and former London Metropolitan Police chief John Stevens.

Ljungqvist said FEI was now a frontrunner among Olympic sports in tackling doping issues.

"They felt they had a problem and they didn't hide it," Ljungqvist told the Associated Press in a telephone interview. "The first way to solve a problem is to recognize that you have one."

He said the FEI now followed WADA guidelines on out-of-competition testing, targeting support staff as well as athletes and requiring riders to keep a logbook of their horses' treatments, similar to the biological passport used in cycling.

The rules approved Thursday will take effect in January and be tested at the 2010 World Equestrian Games in the United States. World championships in eight disciplines will be held Sept. 25-Oct. 10 in Lexington, Kentucky.