The California Department of Food and Agriculture (CDFA) has confirmed that two horses in Los Angeles County have tested positive for equine herpesvirus-1 (EHV-1).

“On Nov. 3, 2016, a 5-year-old Saddlebred displaying severe neurologic signs and a 10-year-old Saddlebred … displaying moderate neurologic signs were confirmed positive for the non-neuropathogenic strain equine herpesvirus-1 at the California Animal Health and Food Safety Laboratory,” a CDFA statement said. “Due to severity of clinical signs, the 5-year-old horse was euthanized on Nov. 3. The department has issued a quarantine for exposed horses at the facility and has implemented enhanced biosecurity measures. All exposed horses will have temperatures taken twice daily and be observed for clinical signs compatible with EHV.”

The CDFA said the two horses that tested positive, along with four others, recently returned from a horse show in Las Vegas, Nevada, that took place Oct. 27-29.

“These horses returned to the California home premises on Oct. 30,” the CDFA said. “Out of an abundance of caution, show management has notified trainers/owners participating in the event to recommend twice daily temperature monitoring and observation of compatible clinical signs.”

[brightcove videoid="3027535698001" title="Health Alert: Equine Herpesvirus"]

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (the neurologic form). In many horses, fe