Molecular Detection and Prevalence of Equine Piroplasmosis and Other Blood Parasites in Equids of Western Aegean Türkiye

Equine piroplasmosis (EP), caused by Theileria equi and Babesia caballi, is a tick-borne disease posing significant threats to equine health and the horse industry worldwide. Other vector-borne blood parasites, including Anaplasma phagocytophilum, Trypanosoma spp., and Leishmania spp., can also infect horses; however, their prevalence remains poorly characterized in Türkiye. This study aimed to determine the molecular prevalence of T. equi, B. caballi, A. phagocytophilum, Trypanosoma spp., and Leishmania spp. in equids from the Western Aegean Region of Türkiye. Blood samples were collected from 388 clinically healthy equines across İzmir, Aydın, Denizli, and Muğla provinces. Species-specific PCR assays were performed, and T. equi and B. caballi were detected in 24.74% (96/388) and 12.89% (50/388) of samples, respectively, with co-infections in 3.09%. T. equi and B. caballi infections were detected in horses from all four sampled provinces—Aydın, İzmir, Denizli, and Muğla—except for B. caballi, which was not found in any samples from Muğla. No samples tested positive for A. phagocytophilum, Trypanosoma spp., or Leishmania spp. Prevalence significantly varied by province, breed, age, and sex (p < 0.05). This study demonstrates the considerable prevalence of T. equi and B. caballi in Western Türkiye, underlining the need for routine screening and vector control programs. The absence of other parasites suggests limited circulation; however, continued surveillance remains crucial to safeguard equine health and prevent disease spread.