Authorities have a search warrant to look for as many as 30 dog carcasses on property owned by Michael Vick that is at the center of a dog fighting investigation. But the warrant has not been executed. In a news release, Sheriff Harold D. Brown said the warrant issued May 23 has not been executed at the request of Brown and Surry County Commonwealth's Attorney Gerald G. Poindexter. The release did not say why the two officials leading the investigation into possible dog fighting on the 15-acre property made the request. Brown was not in the office and is the only member of the sheriff's department who can comment on the case, a dispatcher said. Poindexter also was out of the office and did not return a message left by The Associated Press seeking comment.