Four horses that contracted EHV-1, the neurological form of the equine herpes virus, were euthanized at a boarding stable in North Carolina at the end of December.

The deaths were confirmed by the North Carolina Department of Agriculture and Consumer Services, and the cause of the illness was verified at a laboratory in Iowa, where samples were sent for testing.

Twenty-nine horses were exposed to the virus at J&H Stables in Raleigh, and are currently being monitored at the facility, which is under quarantine. It will remain so for at least 28 days after the last signs of fever in any of the horses.