Mice in all groups that were given 100% concentration of haemolymph four days before infection with T. b. brucei experienced a reduction in mean weight between Day 3 and Day 9, with the exception of the group treated with Diminazene aceturate (Control 1), which showed a slight increase in weight throughout the observation period (Table ). In contrast, mice in groups 1-7, which received various arthropod haemolymphs, displayed a slight decrease in weight between days 1 and 11, followed by an increase between days 12 and 21. All mice in the untreated control group (Control 2) died by day 9. Similarly, mice that received 50% concentration of haemolymph prior to infection with trypanosome parasites showed only slight changes in weight throughout the 21-day observation period (Table ). All treated groups, except for the untreated control group (Control 2), experienced a decrease in weight during the first 11 days, followed by a slight increase from day 12 onward. Mice in Control 2, which did not receive pre-infection treatment, showed a reduction in weight during the first 3 days and died by the 9th day of infection. However, there was no significant difference in weight change between the treated groups and the control group (P<0.05).