Source:  CDFA News Release

California EHV-1 Causing EHM Disease Update as of 12 PM 6/1/11 

California has no new confirmed case of Equine Herpes Myeloencephalopathy (EHM) caused by EHV-1. There are a total of 20 confirmed EHV-1/ EHM cases in the state. The last confirmed case was on May 31, 2011.

• The positive confirmed cases are located in the following 13 counties: Amador(1), Colusa(1), Glenn(3), Kern(2), Los Angeles(1), Marin(1), Napa(1), Placer (3), Plumas(1), Sacramento (1), Shasta(1), Stanislaus(3) and Ventura(1).
• Sixteen(16) of the confirmed positive EHV-1/EHM CA cases participated in the National Cutting Horse Association’s Western National Championships in Ogden, Utah.
• Two (2) of the confirmed positive EHV-1/ EHM CA cases participated only in the Kern County Cutting Horse Event on May 13th in Bakersfield, CA.
• Two (2) of the confirmed positive EHV-1/EHM CA cases were exposed horses to an Ogden, UT participant.
• Two (2) confirmed positive EHM horses were euthanized after showing severe neurological signs associated with EHM.
• All positive confirmed EHV-1/EHM cases are under a State Quarantine.