While Ohio veterinarians are busy fighting what seems to be an especially aggressive strain of equine herpesvirus type 1 (EHV-1), two horses were euthanized due to illness from the virus at Penn National Race Course in Grantville, Penn., in an outbreak that appears to be a more typical, sporadic episode. Additionally, at least two Iowa horses have been euthanized after battling what officials believe might be EHV-1.

The two horses at Penn National were euthanized because of severe neurologic signs consistent with EHV-1. Three horses stabled with these animals tested positive for EHV-1, although reportedly, they only exhibited respiratory illness. The training barn is under a self-imposed quarantine, with disinfection protocol in place.

The Philadelphia Park Racetrack, which typically has horses shuttling between Penn National and its facility on a daily basis, placed a restriction on horses shipping in from Penn National (scheduled to end March 19). Racetracks in neighboring West Virginia have also decided to implement the shipping restriction as a precaution.

Nan Henshaw-Roberts, DVM, a veterinarian at the Pennsylvania Department of Agriculture, said, “Every so often we see EHV-1. We had one small outbreak in Pennsylvania last year, so there are isolated incidents of this