ABSTRACT
Two cloned strains of Trypanosoma congolense, of West and East African origin, were used to infect by intradermal inoculation two groups of young adult female Djallonké sheep and West African Dwarf goats. For a 3 month period post-infection, packed red cell volume (PCV), parasitaemia, body weight and clinical parameters were followed to evaluate their trypanotolerant nature and to control the pathogenicity of the two strains of T. congolense. Although the West African strain of T. congolense was more pathogenic than the East African strain, it seemed that the Djallonké sheep and the West African Dwarf goats, despite high levels of parasitaemia and a concomitant drop in PCV, showed a high degree of trypanotolerance, as reflected by zero mortality and an increase in body weight during 12 weeks of observation.