In many horses, the first or only sign of EHV-1 infection is fever, which can go undetected. | Photo: Stephanie L. Church/The Horse

On Nov. 21 the Oklahoma Department of Agriculture (ODA) updated the status of Remington Park racetrack in Oklahoma County following the initial confirmation of a horse there testing positive for equine herpesvirus-1 (EHV-1). Two additional horses have tested positive: one in the index case’s barn, and one in another barn where 100 more horses were exposed.

Both new cases were positive on polymerase chain reaction (PCR) testing, although both were clinically normal and without fever. The new barn has also been quarantined.

The New Mexico State Racing Commission reported in a statement that entry is being barred for horses from Remington Park until further notice