In many horses, the only sign of EHV-1 infection is fever, which can go undetected. | Photo: Kevin Thompson/The Horse

The Equine Disease Communication Center (EDCC) reported May 3 that a Carbon County, Wyoming, horse has been diagnosed with equine herpesvirus myeloencephalopathy (EHM), the neurologic form of equine herpesvirus-1 (EHV-1).

“On April 27, the Wyoming Livestock Board received negative laboratory results for EHV-1 in a blood sample from a horse in Carbon County” that had been exhibiting hind-limb neurologic deficits, the EDCC’s statement said. “Nasal swabs had not been taken. Still concerned about EHM, the owners were advised to impose a self-quarantine and closely monitor all horses for EHM symptoms, including temping two times daily. The veterinary clinic was advised to maintain isolation and resubmit both blood and nasal samples.”

On May 2, the horse’s nasal swab test results were reported as positive for wild-type EHV-1