Correction: This story originally misstated the date a horse in Orange County was euthanized. The second horse from that barn was euthanized March 2.

As equine herpesvirus-1 continues to spread through multiple California counties, with San Juan Capistrano a current hot spot for the virus, organizers announced the cancelation of the Longines FEI Jumping Nations Cup San Juan Capistrano, originally scheduled for May 10-15, along with Week 1 of Blenheim Spring Classic, scheduled to start March 30.

“As we find ourselves in the middle of this uncertain and fluid situation, there is no realistic way for international teams invited to the Longines FEI Jumping Nations Cup USA, to commit to the logistical preparations necessary to compete in early May,” stated a press release Blenheim EquiSports, which organizes both competitions. “It is also only fair to ensure the athletes can plan their competition schedules, at the highest level of the sport, early and effectively.”

The Nations Cup would have been the third qualifier in the Longines FEI Jumping Nations Cup series and was one of three North/Central American & Caribbean Division events in the series alongside competitions in Coapexpan, Mexico, and Vancouver, British Columbia. No final decision as to whether the qualifier will be rescheduled or put out for bid has been made, an Fédération Equestre International spokesperson said.

“For several weeks, the FEI has closely monitored the development of the EHV-1 outbreak in California and supports the decision to close down competition. Stopping movement of horses is key to prevent further spread of the virus,” FEI Veterinary Director Göran Akerström said in an FEI press release.

In the same statement, Blenheim EquiSports announced that it is canceling its Spring I Classic show—which would have started within the 28-day halt to equestrian events recommended last week by the California state veterinarian and the California Department of Food and Agriculture, and working to restructure the schedules of the remaining two weeks of that series at Rancho Mission Viejo Riding Park in San Juan Capistrano “that, if allowed, will be held under the highest standards of biosecurity and horse health protocols.”

Managers of the Orange County facility also are offering to lend their temporary stalls, at no cost, to private facilities who need them for isolating horses at home. People who need to borrow stalls can email Blenheim EquiSports to do so.

Counties currently affected by the ongoing EHV-1 outbreak in California. Note that the red color in San Mateo County relates to a previous outbreak at a large boarding facility, and that only EHV-1 has been reported there linked to cases first reported at Desert International Horse Park (Riverside County) starting Feb. 11. Map Courtesy Of California Department Of Food And Agriculture

Third OC Barn Quarantined

Meanwhile, CDFA announced over the weekend that a third facility in Orange County has been placed under quarantine after a 10-year-old warmblood gelding displaying neurological symptoms there was confirmed positive for equine herpesvirus myeloencephalopathy  secondary to EHV-1, along with two other horses with fevers only who tested positive for EHV-1.

“There is no known epidemiological link to any other current EHM incidents at an event premises,” CDFA noted in announcing the new quarantine.

Outside of that facility, the total number of confirmed EHV-1 and EHM cases linked to an outbreak first identified Feb. 11 at the Desert International Horse Park in Thermal now stands at 64, and includes one more horse euthanized after developing severe neurological symptoms, based on the most current numbers from CDFA and the Equine Disease Communication Center.

The total number includes 34 cases at DIHP (three EHM, 31 EHV-1 with fever) and another 30 cases reported between two large Orange County facilities.

Chronicle Archive Photo

At the first of those facilities, where a horse who had attended a show at DIHP developed a fever after returning home and a horse exposed to him at the home barn then developed EHM and was euthanized, a second horse was euthanized March 2 and total cases now stand at 20 (two EHM, 18 fever only). CDFA said the euthanized horse was confirmed by necropsy to have EHM secondary to EHV-1.

At the second Orange County facility, 10 total cases have been reported as of March 5—two horses that were euthanized with EHM, and eight cases displaying fever only or mild clinical symptoms, according to CDFA reports.

In Los Angeles County, where a horse who had attended the LA February Show became ill after returning to its home barn and ultimately was euthanized after developing severe neurological symptoms, no other cases have been reported beyond that one. Although some horses who traveled from DIHP also attended the LA February show, officials have said no link between the cases has been confirmed.

EHV-1 Resources:
• Read all of the Chronicle’s coverage of the 2022 California EHV-1 outbreak.
• Learn more about biosecurity best practices recommended by USEF.
• See the most recent case numbers and quarantine alerts from CDFA.
• Learn more about EHM and EHV-1 from CDFA’s EHM factsheet.