Comparative biochemical changes induced by experimental infection of <i>Trypanosoma congolense</i> and <i>Trypanosoma brucei</i> in West African Dwarf (WAD) sheep

Abstract

Trypanosomosis is still a major impediment to livestock production in most tropical environments despite various efforts geared towards eradicating the disease. Small ruminants are known to be fully susceptible to pathogenic trypanosome infections, however, studies in small ruminants are still scanty compared to large ruminants. Comparative pathogenicity and biochemical changes in twenty West African Dwarf (WAD) sheep aged between 8-10 months were investigated. Sheep were randomly assigned into groups A and B and experimentally infected with either Trypanosoma congolense or Trypanosoma brucei. Both species of trypanosomes caused significant but varying degrees of alterations in the biochemical parameters studied. There was a consistent and significant increase (P<0.05) in the levels of total proteins, globulin, fibrinogen, urea, creatinine, sodium, bicarbonate, inorganic phosphate and chloride from day 21 post infection in both groups, and these were sustained till the experiment was terminated. Similarly, the levels of albumin, cholesterol and albumin/globulin ratio progressively decreased (p<0.05) post infection starting from day 28, whereas potassium levels remained unchanged throughout post-infection period. There was a strong positive correlation between total protein and urea in groups A and B (r = 0.937 and r = 0.908), respectively as well as between total protein and creatinine in groups A and B (r = 0.937 and r = 0.908), respectively. Generally, significantly higher biochemical alterations (p<0.05) in T. congolenseinfected
sheep. It can thus be concluded that trypanosome infection in sheep could lead to significant pathological and functional disorders in vital organs including liver and kidney which may have resulted in the biochemical alterations observed; these being influenced by individual trypanosome species.