study was done to assess the effect of Trypanosome brucei rhodesiense on experimentally infected goats and mice to see the effect of the study parasite and to determine the minimum dose that should be used to establish chronic infection. Three goats, identified with number as 908, 713, and 907, received 106, 5 × 104, and 103, parasite in dose volume of 0.5 ml intravenously, respectively. All infected goat showed clinical sign of trypanosomosis. Number 908 was died on 55th day post infection with PCV of 24%. A total of 11 Swiss white mice were also infected to study the effect of the study parasite. A total of 6 mice were infected in the first round (firsts batch), with 1x103 parasites in 0.3 ml dose volume, ip. All mice died before the 5th day post infection. There was no significant change in PCV and body weight almost in all infected mice during the course of infection. A total of 5 mice were infected in the second round (second batch), with 1 × 103 parasites in 0.2 ml dose volume, ip. Mice number 2 died after 72 hours post infection and its parasitaemia was 5.01 × 108. Mice number 1 and 4 were euthanized after 72 hrs and 3 and 5 after 93 hrs with parasitaemia of 2.51 × 108, each. There was statistical significant change in PCV during the course of the infection. The post mortem examination done on these mice reveals no visible inflammatory or pathological changes on examined tissues and organs (lung, heart, liver, spleen, kidney and intestinal organ) The survival period for the second batch of mice was also less than one week. This study indicated that Swiss white mice are more affected by the study parasite than goats.