The mean packed cell volume (PCV) of mice administered 100% concentration of haemolymph from sampled arthropods, four days prior to infection with T. b. brucei, is shown in Table . Mice in groups 1-8 experienced a decrease in PCV levels from Day 3 to Day 12, followed by a slight increase in PCV levels from Day 15 to Day 21. A similar trend was observed in the group treated with Diminazene aceturate (Control 1), while in the negative control group (Control 2), PCV levels continued to decline until the mice died on Day 9. Likewise, mice in groups 1-9 that received 50% concentration of haemolymph four days before challenge with T. b. brucei showed a decrease in PCV from Day 3 to Day 12. All mice in the untreated control group (Control 2) died by Day 9 (Table ). However, the PCV levels of mice in the treated groups (1-9) gradually increased from Day 15 through Day 18 and Day 21. Statistical analysis revealed no significant difference in the mean PCV levels of mice administered 50% haemolymph before infection (P>0.05).