By Kathleen AdamsLong-time equine practitioner Dr. Alex Harthill was hospitalized May 27 after experiencing stroke-like symptoms while working in his Louisville office. After undergoing a series of medical tests, Harthill, 78, is expected to be released from Jewish Hospital Saturday.Speaking by telephone from his hospital room, the legendary veterinarian whose patients over the years include everything from Kentucky Derby and Triple Crown winners, to horses running in the claiming-ranks, joked that when doctors performed a CAT scan, "they found nothing in my head."Several of Harthill's employees first noticed something was wrong with the equine veterinarian when he began to slur his words while dictating a letter."I had a mini-stroke I guess," Harthill said. "But all the tests look good."Two years ago, a horse suffering from West Nile virus fell on top of Harthill breaking both his legs and fracturing his back. As a result of the accident, Harthill has become increasingly unsteady on his feet and earlier this year decided to enter into what he refers to as "selective retirement." Now, the veterinarian who has been in practice for some 57 years has culled his client list and takes on few new patients.But through the years, Harthill has treated many of the big names in racing. The first racehorse he ever treated was Citation, who won the 1948 Triple Crown. Known on the backside for both his quick wit and temper, Harthill vowed the mini-stroke would not keep him away from Churchill Downs for too long. He plans to return to the racetrack on May 30.