Possible tainted feed forces O'Brien to scratch four from Arc

Rainy weather and a softening course led Aidan O'Brien to withdraw his top filly Love from Sunday's Prix de l'Arc de Triomphe (G1). Now failed drug tests blamed on contaminated feed forced him to remove his four remaining horses from Europe's richest race.

He and his son Joseph also had to withdraw four other horses from Breeders' Cup qualifiers that are also on the Arc card at ParisLongchamp. According to Racing Post, they were all feared to have ingested a trace amount of zilpaterol, a drug used by farmers to make cattle bigger before they are slaughtered.

"Unfortunately the results of the urine samples taken from the horses (Friday) have come back positive from the French laboratory," a tweet from Ballydoyle Racing said Saturday night. "There is a possibility that the contaminant may have left their system by the time of racing (Sunday). However we have no guarantee of this, and in order to protect the integrity of racing, we have decided to withdraw all our horses from racing (Sunday)."

Although they did not carry the backing that Love had from bettors before she was withdrawn, Mogul (16-1), Serpentine (16-1), Japan (18-1) and Sovereign (100-1) did make up more than a quarter of the field of 15 that had been drawn into the automatic qualifier for the Breeders' Cup Turf.

O'Brien was also forced to withdraw St Mark's Basilica, the 15-8 second choice in the Prix Jean-Luc Lagardere, from which the winner gets an invitation to the Breeders' Cup Juvenile Turf.

O'Brien's son Joseph is also withdrawing his horses from Sunday's races, including Pretty Gorgeous, the 15-8 favorite in the Prix Marcel Boussac, a "Win and You're In" for the Breeders' Cup Juvenile Fillies Turf. Aidan O'Brien's Mother Earth was 14-1 for the Boussac.

Another Aidan O'Brien long shot, Laburnum, would have been 25-1 in the Prix de l'Opera, a Breeders' Cup Filly and Mare Turf qualifier.

The suspected feed came from Gain Equine Nutrition, which Racing Post said was investigating how the drug may have contaminated its product.