Equine Piroplasmosis Associated with Amblyomma cajennense Ticks, Texas, USA

Abstract

We report an outbreak of equine piroplasmosis in southern Texas, USA, in 2009. Infection prevalence reached 100% in some areas (292 infected horses). Amblyomma cajennense was the predominant tick and experimentally transmitted Theileria equi to an uninfected horse. We suggest that transmission by this tick species played a role in this outbreak.

Keywords

• equine piroplasmosis
• tick-borne diseases
• vector-borne infections
• Theileria equi
• Amblyomma cajennense
• equids