Small ruminants trypanosomosis in the southwest of Ethiopia

A study was conducted in two valleys of the southwest Ethiopia (Didessa and Ghibe valleys) from November 2002 to April 2003 to collect baseline data on the prevalence of trypanosomosis in local breeds of sheep and goats. Blood samples from 533 randomly selected small ruminants of different species, sex and age groups were collected and examined with conventional haematological and parasitological techniques. Among the small ruminants examined during the study period 27 animals (5.1%) were infected with trypanosomes. Most of the infections were due to Trypanosoma congolense (46.7%, 33.3%) followed by T. vivax (26.7%, 25.0%) and the rest was due to T. brucei (6.7%, 8.3%) and mixed infections of T. congolense and T. vivax (13.3%, 25.0%), T. brucei and T. vivax (6.7%, 8.3%) in sheep and goats, respectively. There was no statistically significant difference (P > 0.05) in infection between male and female, among age groups in sheep and goats as well as valleys. Infection between sheep and goats showed significant difference (P < 0.05), the higher being 7.65% in sheep and the lower 3.56% in goats. Mean packed cell volume (PCV) value of parasitaemic animals was significantly lower than (P < 0.01) that of aparasitaemic animals. In an attempt to identify the vectors involved in the transmission of small ruminants trypanosomosis, both tsetse flies of the morsitans group (Glossina pallidipes and G. morsitans submorsitans) and palpalis group (G. fuscipes fuscipes) and mechanical vectors of trypanosomosis that belong to the tabanidae family (tabanus) were captured in the lowlands of Didessa (1400-1780 m above sea level) and Ghibe (1250-1700 m above sea level) valleys. The study revealed that trypanosomosis in sheep and goats is an important disease and small ruminants serve as a potential reservoir of infection for other animals.