Equine piroplasmosis (EP) is a tick-borne or blood-borne protozoal disease of equids (horses, donkeys, mules and zebras). The etiologic agent is one of two protozoan parasites, Theileria equi or Babesia caballi. An organism related to T. equi was described in horses in 2018 and confirmed as a new species, Theileria haneyi. Its clinical significance is currently undetermined.