In the recent Sonoma County instance, a 15-year-old Oldenburg mare from Sonoma County was confirmed positive for the neuropathogenic strain of Equine Herpes Virus-1 on August 23, 2011. Two additional horses on the affected premises were confirmed positive by nasal swab for the same virus. The only clinical sign displayed by these two horses was a fever. An epidemiologic investigation conducted by CDFA revealed minimal disease risk based on lack of animal movement on and off the affected premises. The affected premises were quarantined and the 13 other horses on the property were temperature monitored twice daily and observed for clinical signs for 21 days. No additional horses have demonstrated a fever or any other compatible clinical signs. On September 13, 2011, the quarantine was released.