The following update is from the California Department of Food and Agriculture (CDFA). You can find additional information on their website.
NEW: Third EHV-1 Quarantine in Orange County
March 4, 2022: A 10-year-old Warmblood gelding in Orange County displaying neurological signs was confirmed positive for equine herpesvirus myeloencephalopathy (EHM, also known as neurologic equine herpesvirus) secondary to infection with equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 4. Febrile horses were reported on the premises prior to this EHM case confirmation, including two horses that tested positive for EHV-1. CDFA has been onsite and will quarantine any exposed cohorts. There is no known epidemiological link to any other current EHM incidents at an event premises.
Second EHV-1 Quarantine in Orange County
March 5, 2022:Two additional horses on the premises displaying fever or mild clinical signs were confirmed positive for EHV-1 on March 5. CDFA will continue to closely monitor this situation. To date, there have been two confirmed EHM cases (EHV-1 infection with neurological signs) and eight positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 3, 2022: A 22-year-old Thoroughbred gelding in Orange County displaying neurological signs starting on February 28 was confirmed positive for equine herpesvirus myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 3. Another horse on the premises, a 22-year-old Warmblood gelding displaying neurological signs starting on March 1, was confirmed positive for EHM secondary to EHV-1 on March 3. Both geldings were euthanized due to severity of clinical signs. Additionally, six other horses on the same premises displaying fever only or mild clinical signs have tested positive for EHV-1. The 350 exposed horses on the home premises have been isolated and quarantined. CDFA will continue to closely monitor this situation.
EHV-1 Quarantine in Los Angeles County
March 3, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
EHV-1 Quarantine in Orange County
March 5, 2022: One additional horse on this premises, a 14-year-old Warmblood gelding, displayed neurological signs, was euthanized on March 2 and was confirmed positive for equine herpesvirus myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on necropsy on March 5. To date, there have been two confirmed EHM cases (EHV-1 infection with neurological signs) and 18 positive EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 3, 2022: Two additional horses on this premises have been confirmed positive for EHV-1. Both of these positive horses displayed fever only and no neurological signs. CDFA continues to monitor the situation.
EHV-1 Quarantine in Riverside County
March 5, 2022: One additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs was confirmed positive for EHV-1. To date, there have been three confirmed EHM cases (EHV-1 infection with neurological signs) and 31 confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 4, 2022: Three additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1.
March 3, 2022: One additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1.
EHV-1 Quarantine in San Mateo County
March 4, 2022: Three additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on March 4 and have been isolated at the index premises. To date, three EHM cases (EHV-1 positive with neurologic signs) and 32 EHV-1 febrile-only cases have been confirmed. The quarantine will be released when all positive horses have had two consecutive negative tests seven days apart. CDFA continues to actively monitor the situation.
March 3, 2022: Four additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on March 3 and have been isolated at the index premises.
