Autochthonous dogs from Liberia/West Africa were reared trypanosome-free and brought to West Berlin/germany. Together with Beagle dogs they were infected cyclically by tsetseflies with Trypanosoma congolense. While the European dogs died soon of the trypanosomal infection, the African dogs developed milder parasitaemias and remained clinically unaffected. The authors' opinion is, that this dog model could make a contribution to research on trypanotolerance.