The California Department of Food and Agriculture updated a neurologic equine herpesvirus (equine herpesvirus myeloencephalopathy or EHM) outbreak with the following:

A 14-year-old Warmblood gelding currently at the Sonoma County event premises displaying fever on August 4 was promptly isolated and subsequently confirmed negative for EHV-1 on August 4. CDFA was on site at the Sonoma County premises on August 4. 

The two confirmed positive non-neurologic EHV-1 cases at the index premises—a 5-year-old Warmblood gelding and a 14-year-old pony mare—have both had a first negative test confirmed on August 4. 

CDFA was onsite at the Sacramento County index premises on August 3. No additional cases or clinical signs have been reported. CDFA continues to actively monitor the situation.

In the initial outbreak, seven horses were confirmed with EHV and six were suspected.

See the previous article on this outbreak here.

Information for this report was provided by the Equine Disease Communication Center.