Molecular Prevalence and Genetic Characterization of Bovine Tick-Borne Protozoa in Thai and Imported Beef Cattle in Thai-Myanmar Border and Infesting Ticks from Kanchanaburi Province, Thailand.

Tick-borne protozoa (TBP), including Babesia spp. and Theileria spp., cause substantial health and productivity losses in cattle. In Thailand, most epidemiological studies have focused on dairy herds, while beef cattle remain underinvestigated. This study assessed TBP infections in beef cattle and their ticks at the Thai-Myanmar border. Blood samples were collected from 158 beef cattle, including local animals from Thong Pha Phum and Sangkhlaburi districts and cross-border cattle imported from Myanmar. Engorged ticks, predominantly Rhipicephalus microplus, were removed and identified morphologically. DNA was extracted from blood and tick samples, and PCR assays were performed to detect Babesia and Theileria species. Overall, 51.3% of cattle were positive for Babesia or Theileria DNA. Babesia bigemina (10.8%) and Babesia bovis (8.2%) were the most frequently detected species. Infection prevalence was higher in local cattle from Thong Pha Phum (56.0%) and Sangkhlaburi (54.6%) than in cross-border cattle (39.5%). In contrast, ticks collected from cross-border cattle showed a significantly higher prevalence of TBP DNA (40.0%) compared with ticks from Thong Pha Phum (12.8%) and Sangkhlaburi (8.7%). These findings provide important epidemiological evidence of TBP circulation at the Thai-Myanmar border and highlight the influence of cattle movement and tick exposure on pathogen distribution and spread in this region.