Infectivity and Pathogenicity of Sokoto (Northern Nigeria) Isolate of Trypanosoma evansi in West African Dwarf Goats

摘要

Based on the previous reports on the existence of variations in the infectivity and pathogenicity of Trypanosoma evansi in the field, sixteen West African Dwarf (WAD) goats were experimentally infected (I.V) with (2.0×106) Sokoto isolate of Trypanosoma evansi. Clinical signs, temperature, hematological, gross and histopathological changes in responses to the experimental infection were determined in the goats. All the infected goats developed parasitaemia 3 days post infection (dpi) with slight increase in temperature in the infected goats, decreased mean PCV % in the infected groups to as low as 18±1.47 from 22.50±0.87. There were leucopenia and lymphocytosis in both infected and uninfected groups. Serous atrophy of fat around the heart and kidneys was observed in goats from two groups (A and B and a goat from group (C) revealed pale liver. Microscopically, there were no pathological lesions in the organs of the sacrificed goats from both infected and uninfected groups. The ability of the parasite to be infective and pathogenic to mice and rat after serial passaging through WAD goats was also tested and proven to be infective and pathogenic. It was discovered that the parasite disappeared from both peripheral circulation and body tissues/organs after 14 days. It was observed that infection of WAD Goats with Trypanosoma evansi (Sokoto isolate) does not produce noticeable clinical signs, gross and histopathological lesions and it is self-limiting.