title: Theileria orientalis: a review.
abstract: Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.
authors.affiliation: a Ministry for Primary Industries , PO Box 2526, Wellington , New Zealand.
authors.forename: J G
authors.initials: JG
authors.lastname: Watts
authors.affiliation: b Dawbuts Pty Ltd , PO Box 1118, Camden NSW 2570 , Australia.
authors.forename: M C
authors.initials: MC
authors.lastname: Playford
authors.affiliation: a Ministry for Primary Industries , PO Box 2526, Wellington , New Zealand.
authors.forename: K L
authors.initials: KL
authors.lastname: Hickey
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D009520:New Zealand / Q000453:epidemiology; D016794:Theileria / Q000145:classification* / Q000502:physiology; D013801:Theileriasis / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology* / Q000473:pathology
chemical_list: D000977:Antiparasitic Agents
keywords: Theileria orientalis; anaemia; cattle; theileriosis; tick-borne protozoal disease