Three cases of EHV-1 diagnosed in California | Horsetalk.co.nz

Three horses from a property in Sonoma County, California, have tested positive for the neurological strain of Equine Herpesvirus-1 (EHV-1).

The California Department of Food and Agriculture says the cases are not linked to the May outbreak centred on the National Cutting Horse Association Western National Championship held in Ogden, Utah.

That outbreak across US western states resulted in 22 cases in California horses.

The department said the first case in the Sonoma County outbreak was confirmed on August 23, in a 15-year-old Oldenburg mare.

The mare, it said, was isolated, quarantined and was undergoing treatment at a veterinary referral hospital.

The premises of origin was placed under veterinary observation and the potentially exposed horses' temperatures were being monitored twice daily.

The following day, two additional EHV-1 cases were confirmed by nasal swabs at the premises of origin.

The only clinical sign displayed by the horses was a fever.

The department said 13 other horses currently on the property are being monitored. "Current epidemiologic investigation findings indicate minimal risk of disease spread from this closed premises," it said.

As of Monday, no new cases had been identified.