Equine Piroplasmosis

Distribution and transmission
Equine piroplasmosis has become increasingly familiar to veterinarians in Europe and the United States but is generally less well known in the UK unless we happen to have investigated a chronically infected imported horse. This tick-borne protozoal infection is endemic in many tropical and temperate countries with historical exceptions including the UK, Eire, northern Europe, Australia, Japan, Canada and the United States. The causative parasites Theileria equi and Babesia caballi are transmitted primarily by the feeding activity of infected ticks, but also by the transplacental route, contaminated needles and veterinary equipment. Worldwide disease distribution is determined by the co-existence of equid populations with suitable species of tick vectors. The 2008 outbreak of piroplasmosis in Florida (Short et al. 2012) highlighted its economic impact on the equine industry. In Europe, the discovery of high seroprevalence in Switzerland (Sigg et al. 2010) and confirmation of endemic disease in the Netherlands (Butler et al. 2012) should both serve to heighten awareness of this apicomplexan parasite. [...]