Horse racing-International Star scratched from Derby field

May 2 (Reuters) - International Star has been scratched from Saturday's Kentucky Derby over concerns over a possible abscess in his left front foot, owner Ken Ramsey said. Without International Star, rated a 20-1 shot in the early betting line, the field is down to 18 horses at Churchill Downs for the first race of the Triple Crown series for 3-year-olds. Ramsey said the state veterinarian did not like the way the horse jogged down the shedrow on Saturday morning at "Our blacksmith took the left-front shoe off and there was definitely some heat on the inside quarter of the left-front foot," the horse owner said. "Something's brewing in there, probably an abscess. There's nothing major wrong with the horse whatsoever. We think we'll probably have him ready to come back for the Preakness but time will tell." International Star, winner of three in a row including the Louisiana Derby in his last start, was slated to go off from the 12th post position. Post position number one will be left open, and all other horses will slide down with no gaps. "It's a devastating blow to come this far. I thought I had a decent shot at winning the race," said Ramsey. (Reporting by Larry Fine in New York; Editing by Gene Cherry)