There has been a surge of diagnostic activity at the Oregon State University Veterinary Diagnostic Laboratory (OSU VDL) in the wake of the recent outbreak of Equine Herpesvirus-1 (EHV-1) infection and Equine Herpes Virus Myeloencephalopathy (EHM) in horses in the western United States. Samples from several areas of Oregon have been submitted to the OSU VDL for the real-time PCR diagnostic test for this virus. EHV-1 can cause a variety of clinical problems in horses, including profound, life-threatening neurologic disease.
EHV-1 infection and EHM were identified in horses that attended a major horse event in Utah in late April and early May. Horses that may have been exposed to the virus at the event then returned to their home farm or equine facility, taking with them the potential to expose additional horses to the virus. Some of those horses returned home to Oregon.