PA Horses Tested Positive for Neurologic Equine Herpesvirus (EHV-1)

The Pennsylvania Department of Agriculture reports that specimens collected from 3 of 4 horses at a boarding/riding stable in Allegheny County have tested positive for neurologic Equine Herpesvirus (EHV-1). The 3 positive horses in addition to a fourth untested horse began developing neurologic signs on July 17,2009 (progressive paralysis and recumbency) and deteriorated to a point where euthanasia was necessary. On Monday July 20, 2009, an official quarantine was placed on the entire premises including 4 barns housing 117 horses by the Pennsylvania Department of Agriculture. A fifth horse has since developed signs of the disease. Thus far all horses that have developed clinical signs of EHV-1 were housed in the same barn. Testing and monitoring of temperatures of the remaining exposed horses is ongoing. Traces of all horses that might have left the facility since July 7 are underway and notifications will be given as results become available. The quarantine will remain in effect until a period o f 21 days has elapsed without relevant clinical signs in any horses. Once this point has been reached, all horses will be tested for Neurologic Equine Herpesvirus 1. The quarantine will be released when all horses test negative. Equine herpesvirus causes upper respiratory infection and in some cases severe neurological disease may develop. There is currently no known method to reliably prevent the neurologic form of EHV-1 infection. It is recommended to maintain appropriate vaccination procedures in an attempt to reduce the incidence of the respiratory form of EHV-1 infection. Transmission occurs primarily by direct nose to nose contact or contaminated hands, equipment, feed and water. It can also be spread up to 35 feet by airborn droplets. This virus is not associated with any human health risk. Pennsylvania Department of Agriculture Bureau of Animal Health and Diagnostic Services By Craig Shultz, DVM, Telephone No: 717-772-2852 DISCLAIMER: This notification does not constitute a press release from the Pennsylvania Department of Agriculture. The content is intended for the informational purposes of those involved in the animal health community in the Commonwealth.