Boise, Idaho - The Idaho State Department of Agriculture received confirmation of a case of equine herpesvirus (EHV-1) in Gem County, Idaho.

A mare at a private equine facility in Gem County aborted a pregnancy in late February. On February 27, 2023, the ISDA received laboratory confirmation the abortion was caused by EHV-1 infection. In recent weeks, several other mares on the facility either gave birth to weak foals or experienced an unexpected loss of pregnancy, but no diagnosis was confirmed. All horses on the property are current on all recommended vaccinations.

No horses on the property have demonstrated any respiratory or neurological symptoms and have not traveled in the last six months, including the affected mare.

ISDA urges horse owners to incorporate preventative biosecurity measures while transporting or boarding horses at facilities with regular traffic. Preventative biosecurity measures are especially important where horses are likely to come in contact with new horses such as at rodeos or fairgrounds. At this time, the decision to cancel upcoming equine events and competitions remains with the event coordinators at each host facility. Should horse owners elect to participate in events, they are strongly urged to implement enhanced biosecurity.

Several preventative biosecurity measures are important in minimizing a horse’s risk of contracting the virus:

• Disinfect stalls before use.
• Never share water or feed buckets and tack or grooming equipment.
• Avoid unnecessary contact with other horses.

Additionally, people who work at multiple equine facilities should practice biosecurity measures by washing hands and changing footwear and clothing before entering each facility.

ISDA will provide an update if more details develop. Do not hesitate to call the ISDA office (208) 332-8500 or email info@isda.idaho.gov with any questions or concerns.