 Foals of AQHA-registered stallions and mares born on or after January 1, 2007 that carry HYPP will be required to be HYPP tested and have their HYPP status designated on their registration papers.Both drugs are controversial, in part because they are considered drug maskers and diuretics that can make it difficult to detect the presence of other drugs in the horse's system.On one side, it is argued that the United States Equestrian Federation (USEF), which sponsors show competition for many different horse breeds, and the International Federation for Equestrian Sports (FEI), which governs international and Olympic equestrian competition, ban the use of furosemide.