We are currently fielding a lot of questions regarding EHV-1 in the office and out in the field. EHV (Equine Herpes Virus) causes the disease commonly known as rhinopneumonitis in equids. There is no specific vaccine for the neurologic form of EHV-1, although we regularly vaccinate horses for the respiratory form of the virus (part of the "flu/rhino"). Horse-to-horse contact, aerosol transmission, and contaminated hands, equipment, tack, and feed all play a role in disease spread.
Most current information from the CDFA website:
EHV-1 Disease Update as of 8am 5/18/2011
10 confirmed cases of Equine Herpes Myeloencephalopathy caused by EHV-1.
Currently there is no evidence of EHV-1 disease spread outside the cutting horses who participated in the Odgen, Utah event.
The California Department of Food and Agriculture has been updating their website regularly regarding this disease:
http://www.cdfa.ca.gov/ahfss/animal_health/equine_herpes_virus.html
The CDFA also has a fact sheet with more information regarding EHV-1:
http://www.cdfa.ca.gov/AHFSS/Animal_Health/pdfs/EHV-1FactSheetSept2010.pdf
UC Davis fact sheet:
http://www.vetmed.ucdavis.edu/ceh/currenthealth.cfm