WASHINGTON (AP) — Top horse racing industry figures took different sides before Congress on Thursday over whether the sport needs federal oversight to ban doping.

"We need a new and tougher federal law," said Barry Irwin, whose Team Valor ownership group won last year's Kentucky Derby with Animal Kingdom. He said states don't do an adequate job regulating horse racing, and that a national law is needed so that "all states will be on a level playing field."

But Kent Stirling, chairman of the National Horsemen's Benevolent & Protective Association's medication committee, said in prepared remarks that uniform rules should be implemented by a national compact of states. He said they shouldn't be "imposed by the federal government, which has no experience or expertise in horse racing." Stirling's group represents thoroughbred horse owners and trainers.

Sen. Tom Udall, a New Mexico Democrat who is chairing the hearing, has proposed legislation to ban race-day medication in horse racing.

"The chronic abuse of horses with painkillers and other drugs is just plain wrong," Udall said. "And it is dangerous. An injured horse, feeling no pain, continues to charge down the track. This endangers every horse. It endangers every rider. And, in the long run, it endangers the sport itself ... Congress should not tolerate doping and cheating in interstate horse racing."

Udall said Congress considered legislation regulating the sport in the 1980s.

"And industry groups insisted that congressional action was not needed," he said. "Well, it was needed then. And over 30 years later, the need has only increased."

Udall's bill would ban substances such as Lasix, a diuretic that can enhance performance. Lasix is banned in most other countries.

Stirling defended the use of Lasix, which is used commonly to stop bleeding in the throat and lungs of racehorses. He said it was necessary to keep horses healthy and it would be inhumane to withhold it.

"Lasix is not performance-enhancing," he argued.