LEXINGTON, Ky. - Dubai Millennium, Darley Stud's English champion and promising young stallion,was euthanized Sunday night because of an acute case of grass sickness. Owner and breeder Sheikh Mohammed al Maktoum Dubai Millennium, said he considered Dubai Millennium to be the best horse he ever campaigned.

A 5-year-old Seeking the Gold horse, Dubai Millennium became ill early last week and underwent colic surgery to relieve intestinal blockages on Monday and Tuesday. Attending veterinarians at the Greenwood, Ellis, and Partners clinic in Newmarket determined through an intestinal biopsy that Dubai Millennium had an acute case of grass sickness, which affects about 200 horses annually in Britain, mainly in the North of England and in Scotland.

"Dubai Millennium became uncomfortable on Sunday night, and it was evident that a third emergency surgery was necessary," said John Ferguson, Sheikh Mohammed's bloodstock advisor, in a statement issued by Darley. "It soon became clear that there were complications of the intestinal tract that were inoperable. His prospects were hopeless and, on humane grounds, Dubai Millennium was not allowed to recover from the anesthetic. The horse was the most marvelous patient, and everyone who knew him is very sad to see him go."

Dubai Millennium stood for about $150,000 and had covered his first mares this year at Darley's Dalham Hall Stud near Newmarket, England. He will be buried in the stallion graveyard at Dalham Hall, where he was foaled. He will be buried next to his maternal grandsire, Shareef Dancer.

Dubai Millennium was out of Colorado Dancer (Ireland). He became one of Europe's most highly regarded 3-year-olds in 1999, with victories in the Group 1 Queen Elizabeth II Stakes in England and the Group 1 Prix Jacques le Marois in France. In 2000, he won the Group 1 Dubai World Cup and Prince of Wales's Stakes. Sheikh Mohammed suggested a $6 million match race against Michael Tabor's Montjeu, winner of England's Group 1 King George VI and Queen Elizabeth Diamond Stakes. But 24 hours later, on Aug. 5, Dubai Millennium sustained a condylar fracture in his right hind leg. He retired with a career record of nine wins from 10 races, and total earnings in excess of $4.4 million.

Sheikh Mohammed shipped about 35 mares each from North America and Europe to Dalham Hall to be covered free under a foal-share agreement with the mare owners. Sheikh Mohammed also had booked about 30 mares from his family's Godolphin partnership to be bred to Dubai Millennium. Darley officials said last week that the stallion had covered about 80 percent of his book when he first became ill; the organization is helping participating breeders make alternate arrangements for mares who were not bred before Dubai Millennium's hospitalization.