To reduce the spread of EHV-1, the California State Veterinarian recommends that all hunter/jumper events (the most affected group) be postponed for the next 28 days, all equine events (including clinics) be postponed for the next 14 days, and all non-essential horse movements be postponed for at least 14 days.
In an effort to mitigate the risk of further spread of EHV-1, all U.S. Equestrian Federation-licensed competitions in California are suspended for the next 14 days. USEF does not have any hunter/jumper competitions taking place for the next 28 days; the Desert International Horse Park last month canceled the rest of its winter season in the wake of EHV-1.
Meanwhile, two more horses have been put down in the midst of the EHV-1 wave. A 22-year-old Thoroughbred gelding in Orange County displaying neurological signs starting Feb. 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 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 positive tests for EHV-1. The 350 exposed horses on the home premises have been isolated and quarantined. California Department of Food and Agriculture will continue to closely monitor the situation.
Remember that last year European shows were cancelled for six weeks because of an outbreak of EHV-1 in 10 countries, with 18 horses dying in the epidemic, so it’s important to consider possible consequences and make sure you obey the rules.
As the return to competition protocols are implemented, more horses will be tested which will result in more positive test results for horses. EHV-1 lives dormant in many horses. The increase in positives is expected as asymptomatic horses are tested for EHV-1. The additional testing will allow the USEF community to mitigate the spread of the virus and safeguard horses.
Dr. Nicola Pusterla, professor of medicine and epidemiology, University of California Davis Veterinary Medicine explained, “We all recognize that horses with clinical EHV-1 disease (fever, nasal discharge and even neurological signs) are high risk when it comes to risk of transmission. What most people forget is that infection does not always translate into disease, meaning that adult horses can shed EHV-1 without displaying any abnormal clinical signs.” The expected increase in confirmed positive EHV-1 cases is not necessarily alarming if the horse is asymptomatic.
As a further measure to protect horses and facilitate tracking, USEF will be providing an EHV-1 Declaration Form to competitions for competitors to complete when they arrive on competition grounds.
USEF will also make available an EHV-1 Test Result Form to be submitted to EHV@usef.org along with evidence of negative test results. These documents will be required under the return to competition protocol in order to get a horse’s ineligibility status lifted. This return to competition protocol applies to any horse that has been on the DIHP or Rancho Murieta showgrounds, or any horse that has been exposed to a horse confirmed positive for EHV-1 off competition grounds in the past 14 days. This will allow the horse to be released from the EHV-1 Ineligibility List.
FEI Return to Competition Protocols
In order for a horse to return to FEI competition, the following requirements must be met:
• FEI horses MUST have a negative EHV-1 PCR test to return to competitio
• Two negative PCR tests within 14 days, one at Day 7 and one at Day 14
OR
• One negative PCR test within 21 days, at Day 21
USEF Return to (National) Competition Protocols
In order for a horse to return to USEF (National) competition, the following requirements must be met:
• Two negative PCR tests within 14 days, one at Day 7 and one at Day 14
OR
• One negative PCR test within 21 days, at Day 21
OR
• 28 days without a test, if the horse has been isolated for a minimum of 28 days