Part of trainer Peter Miller’s base at the San Luis Rey Downs training center in Bonsall, Calif., is under quarantine after a horse in his care was euthanized Tuesday at a veterinary clinic following a diagnosis of equine herpesvirus, a highly contagious disease, according to California equine medical director Jeff Blea. Miller’s operation has more than one physical barn at San Luis Rey Downs. The quarantined runners represent a segment of the stable’s overall setup. Miller has a small number of horses based at Santa Anita that are not affected. The affected barn at San Luis Rey Downs is under a 21-day quarantine period. On Wednesday, veterinary officials employed by Santa Anita, and working with Miller, were undertaking “biosecurity measures” to isolate the affected barn, Blea said. Blea said such measures include foot baths and frequent hand washing for stable staff as well as enhanced fencing. The horses will not be allowed to leave San Luis Rey Downs and will have their own dedicated training time, Blea said. “We plan to restrict movement of those horses and prevent comingling of horses that haven’t been exposed,” Blea said. “The barn will be isolated, and only that barn will be isolated. “Peter has been an exemplary individual in ‘What do you need me to do?’ He’s doing his part.” :: Bet with the Best! Get FREE All-Access PPs and Weekly Cashback when you wager on DRF Bets. Blea compared the security measures as similar to the way foreign horses are housed and allowed to train before clearing quarantine in advance of Breeders’ Cup races. Miller said in a text message that his two barns at San Luis Rey Downs will have “separate people and equipment in each barn” during the quarantine period. Each barn has 40 horses, Miller wrote. Blea said a horse trained by Miller was hospitalized over the weekend and was euthanized after showing neurological difficulties. Blea did not identify the stricken horse. “The horse got down and could not get up,” Blea said. Miller had five horses withdrawn from Friday’s opening day of the fall meeting at Santa Anita. He has three entered on Saturday. One of the horses entered for Saturday, Ivory Moon, is a recent arrival from trainer Brian Lynch’s stable in Kentucky. Ivory Moon was sent straight to Santa Anita and will be allowed to run in Saturday’s first race, Blea said. Blea said that veterinary laboratories are required to report equine herpesvirus, or EHV-1, cases to state officials. The diagnosis was made on the basis of lab findings, Blea said. “It’s a reportable disease,” Blea said. EHV-1 outbreaks have occurred at other tracks in recent years. Blea emphasized that the disease affects all disciplines of horses. “It’s a disease in the equine population,” he said. “You see different outbreaks in the show horse world and polo horses. It’s not specifically racehorses.” Miller is one of the most prominent trainers in California. At the Del Mar summer meeting that ended earlier this month, Miller won 13 races, finishing in a tie for sixth in the trainer’s standings. – additional reporting by Brad Free :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.