Synonyms: Piroplasma gibsoni, Achromaticus gibsoni, Babesiella gibsoni, Pattonella gibsoni, Nuttallia bauryi.
Disease: Canine babesiosis, Lahore canine fever, tick fever.
Hosts: Dog, jackal (Canis aureus), wolf, Indian wild dog (Cuon dukhensis), fox. The jackal is the natural host in India.
Geographic Distribution: India, Ceylon, parts of China, occasionally North Africa.
Morphology: This species is smaller than B. canis and does not have its characteristic paired, piriform trophozoites. The trophozoites of B. gibsoni are usually annular or oval and not more than 1/8 of the diameter of the host erythrocyte. Occasionally, large ovoid forms half the diameter of the host cell or thin, elongate forms reaching almost across the cell may be found.
Life Cycle: Similar to that of B. canis. The vectors in India are Haemaphysalis bispinosa and Rhipicephalus sanguineus. Transmission is thru the egg and stage-to-stage in the former, and stage-to-stage in the latter.
Pathogenesis: This species is only slightly pathogenic for its natural host, the jackal, but is highly pathogenic for the dog, causing marked anemia, remittent fever, hemoglobinuria, constipation, marked splenomegaly and hepatomegaly. The disease usually runs a chronic course, with remissions and relapses of fever, and death may not occur for many months. In imported dogs, however, death is said to occur in 3 to 4 weeks.
Immunity: Dogs which are immune to B. canis are still susceptible to B. gibsoni.
Treatment: Neither trypan blue nor acaprin is effective against B. gibsoni. Treatment with arsenicals such as novarsenobillon or tryparsamide has been suggested, but they are apparently not too satisfactory.