Synonyms: Theileria ovis Rodhain, 1916; Babesia sergenti, Theileria recondita, Theileria sergenti.
Disease: Benign ovine and caprine gonderiosis, benign ovine and caprine theileriosis.
Hosts: Sheep, goat.
Location: Lymphocytes, erythrocytes.
Geographic Distribution: Africa, Europe, USSR, India, western Asia. This species is much more widely distributed than G. hirci.
Morphology: The erythrocytic stages resemble those of G. hirci in shape and size, but are much sparser in infected animals, less than 2% of the erythrocytes being infected in non-splenectomized animals. The Koch bodies resemble those of G. hirci, but have been found only in the lymph nodes and then only after prolonged examination.
Life Cycle: The vectors are Rhipicephalus bursa in the USSR, North Africa and Asia, and R. evertsi in South Africa. Transmission with Ornithodoros lahorensis, Dermacentor silvarum and Haemaphysalis sulcata has been claimed in the USSR (Bitukov, 1953), but this claim is dubious (Neitz, 1959). The stages in the tick are unknown.
Pathogenesis: This species is non-pathogenic or practically so. The incubation period following tick transmission is 9 to 13 days, and the disease lasts 5 to 16 days. The only signs are fever, swelling of the lymph nodes in the region of tick attachment, and slight anemia. These would normally be overlooked in the field.
Immunity: Animals which have been infected are premune. There is no cross-immunity between G. ovis and G. hirci.
Diagnosis: This depends upon identification of the parasites in stained blood or lymph node smears. G. ovis is morphologically indistinguishable from G. hirci, but the small number of parasites present and their lack of pathogenicity may help to differentiate them. Cross-immunity tests may be carried out if desired.
Treatment: None known.
Prevention and Control: These depend upon tick control.