Synonyms: Haematococcus ovis pro parte, Piroplasma ovis.
Hosts: Sheep, goats.
Geographic Distribution: Southern Europe, Middle East, USSR, Indochina, Africa, and other parts of the tropics.
Morphology: This is a large form, measuring 2.5 to 4 by about 2 u. The trophozoites resemble those of B. bigemina and are usually piriform. They occur singly or in pairs; the angle between members of a pair is acute.
Life Cycle: Similar to that of B. bigemina. The vector in Roumania is Rhipicephalus bursa, that in Sardinia is Haemaphysalis punctata, and those in the USSR are Dermacentor silvarum and Haemaphysalis otophila. Transmission occurs both thru the egg and stage-to-stage in R. bursa.
Pathogenesis: This species may cause either an acute or chronic disease. Fever, prostration, marked anemia and hemoglobinuria are present in the acute disease, and affected animals often die. There may be no characteristic signs in the chronic disease.
Immunity: Sheep which are immune to B. motasi are not immune to B. ovis and vice versa.
Diagnosis: Same as for B. bigemina. The parasites are abundant in the peripheral blood during an attack.
Treatment: Trypan blue is effective against this species, as is acaprin. The latter is administered subcutaneously, 0.2 ml per kg of a 0.5% aqueous solution being given.
Prevention and Control: Same as for other species of Babesia.