Six farms are currently under quarantine in New Jersey as a preventative measure against an equine herpes virus outbreak.

Two horses at Sweet Dreams Farm, Farmingdale, N.J., were euthanized with clinical signs consistent with the neurological form of EHV, and another died with similar signs. Two of those horses had presumptive positive tests for the disease and confirmatory testing continues. 

While EHV is not harmful to humans, the neuropathogenic form of the disease is often fatal to horses and is spread quickly from horse to horse.

“Quarantines are necessary to ensure that this serious disease does not spread,” said New Jersey Secretary of Agriculture Douglas H. Fisher. “Our investigation is continuing as we work to protect the health and safety of horses in New Jersey and other states.”

To date, no horses at the other quarantined premises have shown signs of the virus.

The incubation period of EHV-1 clinically affected horses is typically two to 10 days, but infections may be spread for 21 days, the duration of the quarantine.

The Massachusetts Department of Agricultural Resources stated on April 2 that four horses exposed to EHV-1 in New Jersey were later transported to Massachusetts. One of the horses has tested positive and shows symptoms of the virus.

The New Jersey Department of Agriculture has a fact sheet on simple disinfection protocol for EHV-1 at www.state.nj.us/agriculture/pdf/simpledisinfectionprotocolEHV.pdf.