Kent Desormeaux, Maryland's leading jockey, yesterday was given a seven-day suspension for precipitating a two-horse spill in Laurel's 10th race Tuesday. The suspension will begin Sunday.

Laurel's racing stewards faulted Desormeaux for permitting his mount, Proud O Letti, to drop in on Gold Knickers around the far turn. The one-week suspension is standard for such an infraction.

As jockey Clarence (JoJo) Ladner was advancing Gold Knickers along the rail, Desormeaux whipped Proud O Letti right-handed, and his mount angled left, shutting off Gold Knickers. Ladner pulled back on the reins, but Gold Knickers clipped Proud O Letti's heels and fell, hurling Ladner beneath the inner rail. Jockey Mike Hunter went tumbling when his mount, Soda Say, became entangled with fallen Gold Knickers.

Neither Ladner nor Hunter was injured.

This is Desormeaux's first suspension in 11 months.

"The ruling was fair," said Desormeaux, who has a 132-45 victory lead over his closest pursuers, Ladner and Allen Stacy. "It took me a little long to get a hold of {Proud O Letti}, but that's about it. I did what I could, but it was a little late."

Because Desormeaux has been named to ride horses Saturday at Laurel, his suspension cannot begin until Sunday. One of his Saturday mounts, Endless Surprise, is the 121-pound highweight in the $50,000 Challedon Handicap.

Spiffy Lady, a 3-year-old filly who won a $6,500 claiming race for nonwinners Jan. 5, was disqualified and her $3,300 winnings rescinded after she tested positive for Trimethoprim, a sulphur derivative, in a postrace urine sample.

The result does not appear to be the cause of foul play. Pat Brackett, a track veterinarian, said Trimethoprim is an antibiotic. "It's totally innocuous," Brackett said. "It's nothing you would give a horse to change his performance."

Mert Bailes, who trains Spiffy Lady for John Korman Jr., said the positive reading likely resulted from a bad lot of vitamins he gave Spiffy Lady to combat a throat infection. Stewards are investigating.

Mass Avenue, who finished second in Spiffy Lady's victory, was declared the winner by stewards. Mass Avenue had been scheduled to run today against nonwinners, but the stewards' ruling makes her ineligible.