Re-establishing New Zealand’s freedom from Theileria equi after the introduction of a single infected horse.

In May 2020 Theileria equi, a cause of equine piroplasmosis, was detected in a horse that had been imported into New Zealand 15 months previously. Consequently a biosecurity response was initiated. Extensive active surveillance confirmed that no transmission ocurred and that this animal was the only case present in New Zealand. A dossier was supplied to the World Organisation for Animal Health (OIE) and accepted in January 2021, re-establishing New Zealand’s freedom from T. equi.