Quarantine Concerns Woodside Horse Park Boarders An active equine disease quarantine for EHM at Woodside Horse Park

Concerns over EHM Quarantine at California’s Horse Park at Woodside

Equine disease quarantine: San Mateo County

Horse owners frustrated by a lack of communication aired concerns about an equine disease quarantine at a busy San Mateo County Horse Park.

Last week, California veterinary officials confirmed an Arabian mare positive with equine herpesvirus myeloencephalopathy (EHM). The equine herpesvirus-1 (EHV-1) causes the neurologic form of the disease or EHM. Veterinarians are treating the index horse off-site, where it is isolated and quarantined.

The state quarantined five exposed horses on-site in the ‘north’ pasture at the Horse Park at Woodside. Additionally, veterinarians implemented enhanced bio-security measures, which include taking the horses’ temperatures twice daily.

Biosecurity at Horse Park at Woodside
Biosecurity at Horse Park at Woodside

A Horse Park Member contacted Horse Authority on behalf of concerned members and horse boarders. The person spoke to us under the condition of anonymity and provided photos to substantiate the claims.

“[There’s been] no communication from management since the initial email last Wednesday,” the individual said. Apparently, Horse Park Members didn’t receive any information. Since that email, the horse owner says, “we had to rely on rumors…”

The Horse Park at Woodside

The Horse Park at Woodside bustles with horses in-and-out regularly. The equestrian facility spans more than 270-acres and offers horse owners horse boarding, multiple riding arenas, trail riding, a cross-country course, and horse shows.

Barricades restrict access to where five exposed horses reside in a pasture. Although, some are concerned that the arenas and perimeter trails remain open, despite the quarantine.

Katie Flynn, BVMS, is the Equine Staff Veterinarian with CDFA and responsible for equine regulatory disease investigations including this one. She tells us in an email, “activities in all other parts of the facility are permitted to continue as normal as they are not under quarantine or restrictions.”

Dr. Flynn adds, “there is no one size fits all protocol for equine disease quarantines.”

Horses infected with EHM show clinical signs that typically include mild incoordination, hind end weakness, and loss of bladder function.

The quarantine may end as soon as Saturday, November 17, Dr. Flynn tells us, as long as there are no fevers and the horses don’t show any clinical signs of the disease.

Additionally, the index horse continues to improve with supportive treatment in isolation, off-site.


November 21, 2018

The EHM quarantine of all exposed horses was released on November 20, 2018. The index horse was also released.