LEWISTON, ID – The Lewiston Roundup Association announced Wednesday night that it has temporarily closed its equine facilities for 21 days in response to an outbreak of equine herpesvirus (EHV-1).

The closure applies to all incoming and outgoing traffic involving livestock. Association officials said no animals may enter the premises, or leave and return, until at least Dec. 10 or until veterinary guidance indicates it is safe to reopen.

As part of the shutdown, the Nov. 22 and Dec. 6 barrel races have been canceled.

The association said the decision was made out of caution to protect the health and safety of horses on the grounds while efforts to contain the virus continue. EHV-1 is a contagious disease that can spread among horses through direct contact or shared equipment.

According to the USDA, EHV-1 primarily causes upper respiratory disease and abortions/stillbirths in horses. In some cases, it causes a neurological disease called equine herpes myeloencephalopathy (EHM) that can be fatal. EHV-infected horses that don’t develop EHM generally recover with no side effects.

The association is urging horse owners to follow biosecurity measures, including monitoring temperatures twice daily for horses that travel frequently and isolating any animal that develops a fever.