Abstract
The blood parasites of indigenous camels, sheep, goats and cattle were investigated in several localities in Saudi Arabia that are well isolated from any possible mixing with imported animals. The present study is the first detailed investigation on blood parasites infecting indigenous livestock in Saudi Arabia. Trypanosoma evansi and an Eperythrozoon sp. were detected in camels. Sheep and goats were infected with Theileria ovis, Theileria hirci and with Eperythrozoon ovis and cattle with Eperythrozoon wenyoni, Theileria annulata and with a nonpathogenic Theileria sp. Apart from T. evansi and T. annulata, all parasite species are reported for the first time from Saudi Arabia. The detection of an Eperythrozoon sp. form the camel is the first from this host. Theileria ovis and E. ovis were reported from all provinces examined, while T. hirci was confined to eastern and northern parts of the Kingdom. Eperythrozoon wenyoni was found in both of Hofuf and Gizan, but T. annulata occurred in Hofuf only and the nonpathogenic Theileria sp. in Gizan only. Areas of highest camel trypanosomiasis prevalence were heavily infested with tabanid flies whose role in the transmission of the disease was discussed. The pathological effects of the reported blood parasites on their hosts was discussed together with the role of ixodid ticks in the transmission of the Theileria species.