Two barns were placed under quarantine at Los Alamitos Race Course following the death of two horses from equine herpesvirus (EHV-1).

Golden Gate Fields has instituted biosecurity measures for the test barn and starting gate after a fetus aborted by a mare stabled at the track tested positive for the disease.

One racehorse and one stable pony died at Los Alamitos from EHV-1, which can lead to abortions in pregnant mares and horses showing signs of respiratory problems and high fevers. Laboratory results are pending on several suspect cases.

Biosecurity procedures are in place for all communal areas at the track, including the receiving barn, post parade, and starting gate.

The mare at Golden Gate was removed from the track after testing negative for EHV-1. Five other horses that may have been exposed also tested negative.

The mare was stabled in a relatively isolated area of a barn that is not showing any additional signs of sick or fevered horses. Temperatures are being monitored twice daily at the barn, which has not been placed under quarantine.