Synonyms: Haematococcus ovis pro parte, Piroplasma ovis, Piroplasma hirci, Babesiella ovis.
Hosts: Sheep, goats.
Geographic Distribution: Southern Europe, USSR, thruout the tropics and in some subtropical regions.
Morphology: This is a small species, about 1 to 2.5 u long. Most of the parasites are round, and they usually lie in the margin of the host erythrocytes. The angle between the paired, piriform trophozoites is usually obtuse.
Life Cycle: Similar to that of B. bovis. The vectors in the USSR are Rhipicephalus bursa and Ixodes persulcatus (Rastegaeva, 1940). B. ovis was found in 2 sheep fetuses by Donatien, Lestoquard and Kilcher-Maucourt (1934).
Pathogenesis: This species is less pathogenic than B. motasi, but it may cause fever, anemia and icterus. Usually not more than 0.6% of the erythrocytes are infected.
Immunity: There is no cross-immunity between B. ovis and B. motasi.
Diagnosis: Same as for B. bovis.
Treatment: Trypan blue is ineffective against B. ovis. Acaprin can be used in the same way as for B. motasi, but it is not as effective. Acriflavine is recommended, a single intravenous injection of 0.15 g being given.