RESUMEN
Background: Animal trypanosomosis is a major cause of economic loss in livestock production in Africa. A suggested control measure is to use breeds with traits of trypanotolerance. The study examines the effect of natural Trypanosoma vivax challenge on haematological parameters in two trypanotolerant cattle [N'Dama and West African Short Horn (WASH)] herds. Methods:T. vivax-specific primers were used to diagnose T. vivax infection in an N'Dama herd at Cape Coast in southern Ghana and a WASH herd at Chegbani in northern Ghana from May to July 2011 in a cross-sectional study. Levels of haematological parameters comprising packed cell volume (PCV), haemoglobin (Hb) concentration and total red blood cell (RBC) and white blood cell (WBC) counts; differential WBC counts (neutrophils, lymphocytes, eosinophils, monocytes and basophils); and RBC indices of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were determined in blood samples and then compared between infected and uninfected cattle. Results: We found that haematological indices for infected and uninfected animals in both breeds were within the normal range. However, the mean PCV values for T. vivax-infected WASH and N'Dama were lower in infected compared to uninfected animals. The difference was significant ( p< 0.05) in N'Dama but not in WASH. The RBC indices were higher in infected N'Dama compared to infected WASH with a significant difference in total RBC ( p < 0.05). Conclusion: We conclude from our findings that despite the presence of infection by T. vivax, N'Dama and WASH cattle maintained their haematological parameters within acceptable normal ranges, and this underscores the need for routine diagnosis and treatment so that such trypanotolerant cattle do not serve as potential reservoirs of trypanosome parasites.
