A small outbreak of equine herpes at Penn National Racecourse has prompted management of Philadelphia Park to bar horses shipping in to race as well as horses shipping out to "race and return" from the Grantville, Pa. oval.Richard Schnaars, general manager of Penn National, stressed that the situation is "very localized," with only two horses from the stable of trainer Bob Wolfe testing positive for the virus. It is transferred from horse to horse by contact, usually through the nostrils. A 10-14 day quarantine is typical, said Schnaars."The two horses are contained in the same barn and, hopefully, that's all there is," said Schnaars. The affected horses spiked fevers but are currently being treated, he said. In some forms, the equine herpes virus can cause respiratory and neurological problems.Hal Handel, CEO of Philadelphia Park, said that the ban on incoming and outgoing shippers is a "cautionary measure" and would be evaluated on a day to day basis."The worst thing we could do would be to cause it to spread," said Handel. "Until the dust settles, we're playing it safe."