On April 19, the Washington Department of Agriculture confirmed a case of equine herpesvirus myeloencephalopathy (EHM) in Thurston County.
The affected 19-year-old gelding had onset of clinical signs on April 16. Clinical signs included hind limb ataxia and loss of tail tone. The gelding was referred to Oregon State University Vet Hospital and is recovering.
The state has quarantined the gelding's premises, which has 80 horses on the property.