Abstract
In total, 241 sera from clinically healthy adult horses were collected from 6 locations in Saudi Arabia and examined for Theileria equi and Babesia caballi antibodies by an indirect fluorescent antibody test. Antibodies to Theileria equi were detected in 25 horses (10.4%) while the antibodies to Babesia caballi were observed in 18 horses (7.5%). In addition, 7 serum samples were positive for antibodies to both parasites (3%). The horses sampled in Al-Janadriah had the highest prevalence of infection with T. equi at 16.5% and with B. caballi at 8.8%, while the lowest prevalence of infection with T. equi (4.7%) and B. cabal (3.1%) was observed among horses examined from the Dyrab district. However, significant differences (P < 0.05) in seroprevalence were not observed between these districts. This study represents the first report on the status of T. equi and B. caballi infection in the central province of Saudi Arabia.