Equine Herpesvirus Myeloencephalopathy (EHM)

*UPDATE* 05-11-2018
*Los Angeles County Suspect Case* May 9, 2018: CDFA has been notified of a 24-year-old mare in Los Angeles County displaying neurologic signs. The horse was sampled on Sunday and the nasal swab tested positive by a private laboratory. However, subsequent testing by the state regulatory laboratory (California Animal Health and Food Safety Laboratory) revealed negative results. The private practitioner resampled the horse today and samples will be tested tomorrow at the regulatory laboratory. CDFA veterinarian visited the facility today to confirm horse has been isolated and biosecurity recommendations have been implemented. CDFA regulatory action is based on laboratory results from a regulatory laboratory. Thus, a quarantine will be placed if the regulatory laboratory test result is positive.

*Orange County Quarantine * May 9,2018: No New Cases. Enhanced biosecurity measures and twice daily temperature recording for all exposed horses in the quarantine barn continues. No fevers or clinical signs have been reported in the last 10 days. If no additional cases are identified, the barn will be released from quarantine on Sunday May 13, 2018. However, positive horses in isolation will remain under quarantine until they have two negative tests. At this time, all positive horses have had at least one negative test and isolation quarantine release is anticipated early next week.

 

April 29, 2018: One New EHM Case: A 9-year-old mare from the quarantined
barn at the Orange County Facility, displaying mild neurological signs has
tested positive for Equine Herpesvirus-1. Based on clinical signs and the
detection of virus, this horse is classified as an Equine Herpesvirus
Myeloencephalopathy (EHM) case. The mare has been moved to onsite isolation. 
To date, there have been seven confirmed febrile cases of EHV-1 and three
confirmed cases of Equine Herpesvirus Myeloencephalopathy (EHM). CDFA staff
continues onsite monitoring of the situation. 
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April 27, 2018: One new confirmed EHM Case. A 24-year-old mare from the
quarantined barn at the Orange County Facility, displaying neurological
signs has tested positive for Equine Herpesvirus-1. Based on clinical signs
and the detection of EHV-1 virus, the horse has been classified as a case of
Equine Herpesvirus Myeloencephalopathy (EHM). The mare has been moved to
onsite isolation stabling. To date, there have been seven confirmed febrile
cases of EHV-1 ad two confirmed cases of EHM. CDFA staff continues onsite
monitoring of the situation. 
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April 26, 2018: Two new confirmed cases. Two horses from the quarantined
barn at the Orange County Facility, displaying fevers, have been confirmed
positive for the Equine Herpesvirus-1 (EHV-1). The first positive horse
displayed a fever on Monday and was placed in onsite isolation stabling. The
second positive horse initially tested negative over the weekend and was
moved off site for isolation and quarantine. Enhanced biosecurity measures
and twice daily temperature recording for all exposed horses in the
quarantine barn continues. To date, there have been seven confirmed febrile
cases of EHV-1 and the one index case of Equine Herpesvirus
Myeloencephalopathy (EHM). Release of positive horses from quarantine
isolation requires two negative tests seven days apart. CDFA staff continues
onsite monitoring of the situation. 
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April 23, 2018: Two new confirmed cases. Two horses from the quarantined
barn at the Orange County Facility, displaying fevers over the weekend, have
been confirmed positive for the Equine Herpesvirus-1 (EHV-1). Both horses
are in isolation stabling onsite Additionally, the recommendation is for all
horses on the premises have temperatures taken twice daily. Any horse on the
premises with a fever will be tested for EHV-1. To date, there have been
four confirmed febrile cases of EHV-1 all of which are in isolation stabling
onsite and the one index case of Equine Herpesvirus Myeloencephalopathy
(EHM) which is isolated and quarantined off site. CDFA staff continues to be
onsite monitoring the situation. 
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April 13th, 2018: A 17 year old Thoroughbred gelding, originating from an
Orange County facility, displaying neurologic signs has been confirmed
positive for Equine Herpesvirus Myeloencephalopathy. The gelding has been
isolated and placed under quarantine. Exposed horses will be monitored for
clinical signs and temperatures will be taken twice daily. Any horse
displaying a fever or compatible clinical signs will be tested. CDFA will
continue to monitor the situation and post new information as it becomes
available.