Arrangements are pending for Viking Stud owner Rick Littrell, who died at a Lexington hospital Thursday night. He was 50.Littrell and his wife, Pam, operated Viking Stud on Lemmons Mill Road and were regular consignors to auctions. Their two sons both worked at the farm, Joe as farm manager and Mike as yearling manager.Littrell had some health problems over the years related to diabetes. Late last year, he was relegated to a wheelchair for a period of time because of a complication in his leg. His death was due to a blood clot in his lung."He was a quiet guy that worked behind the scenes but was a great horseman," bloodstock agent Mike Akers, a close friend, said. "He really had a passion for the business."He was the kind of guy that you watched work his way up the hard way," Akers added. "He worked in Northern Kentucky for Bill Melton, later worked for Don Sucher (at Echo Valley Farm), and then began leasing his own place. He had developed a good client base, had become a top consignor, and was diversifying into buying mares of his own."Akers said among Littrell's clients was Helen Andrews of Cincinnati, who operated as Twin Hopes Farm. He also represented Lance Robinson and Jerry Bailey and was involved early with David Plummer as he was developing ClassicStar.