Analytical study by cross-sectional was perfomed between November 2015 - April 2016 at Hawa Galan woreda, KelemWollega Zone, Oromia Region, of the country, to know the prevalence of cattle trypanosomosis and to evaluate the factors associated with the prevalence of bovine trypanosomosis. A haemoparasitological examination of buffy coat method was implemented to determine the prevalence of trypanosomosis. A Study population of 428 bovines are selected randomly from three peasant associations (PA) and tested for the presence of the disease. Results indicated that among all animal tested at the study time 26 (6.00%) animals were found positive with the disease. Among the positive results, the proportion of trypanosome species was Trypanosoma congolense18 (69.30%), and Trypanosoma vivax 8(30.70%). The prevalence at all purposively selected PA’s were 12.5%, 3.8%, and 3% for Lemlem, Madawalkituma and Ifajiru. From this finding, the relationship showed statistically significant variation (P < 0.05) among peasant associations and body condition state, the proportion was significantly greater (P < 0.05) in animals that categorized under poor body condition score. The relationships between age and sex of cattle’s shows no statistically significant variation among them . The study indicated that, the proportion of trypanosomosis was greater in anaemic (PCV<24%) cattle’s than non-anemic (PCV>24indicaing trypanosomosis as the cause of a major effect to the health of cattle in study area. So, effective control methods could be applied to decrease the disease and its related economic loss.

Keywords: Bovine, Hawa Galan, Tsetse fly, Trypanosomiasis