A horse at Parx Racing who became ill this week has been determined to have the equineherpesvirus, resulting in two barns at the Pennsylvania track being quarantined. As a result, no horses stabled at Parx will be allowed to ship off the grounds until the quarantine is lifted. No Quid Pro Quo, who won a $25,000 maiden-claiming race for trainer Michael Aro on March 20, became ill Wednesday and was sent to the Mid-Atlantic Equine Center in Ringoes, N.J., which has state-of-the art quarantine facilities. Tests results on Friday revealed that No Quid Pro Quo has the equineherpesvirus. "His back right leg blew up so I sent him right to the clinic," Aro said. Aro is stabled in Barn 30, along with trainer Ron Dandy. Their horses will not be allowed to train or race during the quarantine, which will remain in place for 28 days, as long as no other horses test positive for the virus. Barn 4, where trainers Butch Reid and Keith Nations are stabled, also is under quarantine because Reid claimed Sunshine Wild from Dandy for $40,000 on Tuesday, the day before No Quid Pro Quo became ill. Sam Elliott, the director of racing at Parx, said racing will continue at Parx during the quarantine. As of late Friday afternoon, Elliott had not yet decided whether horses would be allowed to ship in to race. If they are, they will not be allowed to leave during the quarantine. "The thing is, I have very limited space on the backstretch for horses shipping in," Elliott said. The equineherpesvirus is contagious and can cause respiratory and neurological problems in horses. It can sometimes be fatal. Parx was under quarantine for most of last October when a 2-year-old filly tested positive for the equineherpesvirus. There were no other cases during that quarantine. This winter, Sunland Park in New Mexico and Turf Paradise in Arizona were placed under quarantine for the equineherpesvirus. Sunland Park was forced to suspend racing from Jan. 23 to Feb. 26 after 68 horses tested positive for the virus. The Parx quarantine will prevent trainer Ramon Preciado from shipping three horses to Aqueduct on Saturday for New York Claiming Championship Day. Trainer Ned Allard and owner Gilbert Campbell recently supplemented Abiding Star to the Triple Crown for $6,000 and planned to run him in the Federico Tesio Stakes next Saturday at Laurel Park. Allard and Campbell also have been pointing Tom Fool runner-up Always Sunshine to next Saturday's Grade 1 Carter at Aqueduct. It is unlikely either will be able to leave Parx.