Equine piroplasmosis in China, 2000 to 2025: a systematic review and meta-analysis of prevalence and risk factors.

Equine piroplasmosis (EP) is a tick-borne disease of equids caused by Theileria equi, Babesia caballi, and Theileria haneyi. We conducted a PRISMA-guided systematic review and meta-analysis to estimate pooled prevalence in China and identify associated risk factors. PubMed, Web of Science, ScienceDirect, CNKI, Wanfang, and VIP were searched through 15 August 2025. Of 2,626 records identified, 80 studies met the inclusion criteria. Random-effects models were used to pool prevalence estimates, and prespecified subgroup analyses and univariate meta-regression were used to explore heterogeneity and temporal trends. Overall pooled prevalence during 2000-2025 was 31%; species-specific estimates were 24.28% for T. equi and 18.37% for B. caballi. Only one eligible study reported T. haneyi, so its prevalence was summarized descriptively rather than pooled. Statistically significant subgroup differences were observed by host species, fever status, climate class, and detection method. Prevalence was higher in horses than in donkeys and mules, although the mule estimate was based on only five studies and 31 positive cases. Febrile equids had a higher prevalence than afebrile equids, prevalence was highest in Dwb and lowest in Cfa climates, and PCR-based studies yielded a higher pooled prevalence than ELISA-based studies (36.40% vs 23.97%). No significant differences were detected by region, age, sex, season, management system, or sampling year, and meta-regression showed no significant temporal trend. These findings support risk-based surveillance, prioritization of testing in febrile equids, and combined serological and molecular testing to distinguish exposure from active infection.