Comparative Study on Hematological and Plasma Biochemical Responses of Rabbits to Experimental Single and Mixed Infections of Trypanosoma Brucei And Trypanosoma Congolense

Abstract

This study compared the effect of single and mixed infections of Trypanosoma brucei and Trypanosoma congolense on hematological and biochemical parameters in 24 randomly selected male rabbits. Three groups (A, B, and C) of six rabbits each were challenged with 2 x 10⁵ trypanosomes and fourth group (D) with 1ml normal saline without the parasite. Parasites were detected in the blood of the three infected groups at 3-10 days post infection (dpi). There were significant (p < 0.05) differences between the mean PCV, WBC and HB of the infected groups and the non-infected group with the mean PCV of rabbits with mixed infections significantly highest. The developed anemia was normocytic normochromic while the leucopenia was characterized by neutropenia, eosinopenia and lymphocytosis. While no correlation was established between parasitaemia and the plasma biochemical in the three groups, the plasma protein and bilirubin levels were significantly (p < 0.05) elevated, there was significant depletion of glucose levels in the three groups relative to non-infected group and only the rabbits infected with T.congolense had significant (p < 0.05) cholesterol elevation. AST and ALP increased significantly (p < 0.05) in the three groups (A, B and C) but no significant change in the level of ALT. Treatment with diminazene aceturate at 42 dpi effectively reduced the parasitemia to zero level at 49 dpi. In conclusion, hematological and biochemical alterations in single and mixed infections was significant (p < 0.05) relative to non-infected group but not significant when compared within infections except the PCV and urea. This study revealed that single and mixed infections of T. brucei and T. congolense significantly altered some biochemical and hematological parameters of the infected rabbits. While most of these alterations were not significantly different between the single and mixed infections, the PCV and plasma urea levels of mixed infected rabbits were significantly depressed and elevated, respectively.

Keywords: Rabbits. T. brucei, T. congolense, Hematological and biochemical parameters

Nigerian Veterinary Journal, VOL:33(2) 462-474