The blood parasites of indigenous livestock in Saudi Arabia

The blood parasites of indigenous camels (n=310), sheep (331), goats (348) and cattle (43) were investigated in several localities in Saudi Arabia that are well isolated from any possible mixing with imported animals. Trypanosoma evansi (at a prevalence of 13.2%) and Eperythrozoon sp. (3.9%) were detected in camels. Sheep and goats were infected with Theileria ovis (19.9%), T. hirci (6.9%) and Eperythrozoon ovis (3%), and cattle with E. wenyoni (18.6%), T. annulata (20.9%) and a nonpathogenic Theileria sp. (14.0%). Apart from Trypanosoma evansi and Theileria annulata, all the parasite species are reported for the first time from Saudi Arabia. The detection of an Eperythrozoon sp. in camel is the first from this host. T. ovis and E. ovis were reported from all provinces studied, whereas T. hirci was confined to eastern and northern parts of the Kingdom. E. wenyoni was found in both Hofuf and Gizan, but T. annulata occurred only in Hofuf and the nonpathogenic Theileria sp. only in Gizan. Areas of highest camel trypanosomiasis prevalence were heavily infested with tabanid flies whose role in the transmission of the disease is discussed. Atylotus farinosus (from Hofuf, Al-Hafr, Al-Kharj and Buraydah) and A. agrestis (from Gizan, Samitah and Najran) were identified during the study; these are the first reports from these localities. Tabanid flies were rarely seen in any of the other localities studied. The pathological effects of the reported blood parasites on their hosts are discussed together with the role of ixodid ticks in the transmission of Theileria.