Concurrent Naturally Acquired Trypanosome and Gastrointestinal Nematode Infections in Horro Sheep from Anger-Didessa Valley of Western Oromiya, Ethiopia

Abstract

The study was conducted on 82 sheep flocks to determine the occurrence of concurrent infections of nematode and trypanosome as well a s the effect of the parasites on packed cell volume (PCV) from tsetse-affected areas. Faeces were examined using flotation and modified McMaster techniques while blood samples were analyzed using Buffy Coat method and Giemsa-stained smears. The results showed an overall concurrent infection of 2.0% (95% CI: 1.0-3.0%). Among sheep tested parasitological positive for trypanosomes, 40.0% (95% CI: 20.0-60.0%) were concurrently infected with nematode while among trypanosome negative animals, 30.2% (95% CI: 25.0-35.0%) were infected with nematodes and the difference was not statistically significant (p > 0.05). The log-transformed mean nematode faecal egg counts (EPG ± SE) recorded in mixed infection with trypanosome (2.25 ± 0.25) and single infection of nematode (2.30 ± 0.04) were not significantly different (p > 0.05). The EPG and PCV values were negatively correlated which was significant (r = - 0.255, p < 0.001). Among concurrently infected animals, 87.5% (95% CI: 60.0 - 100.0%) had anaemia compared to 58.3% (95% CI: 30.0 - 86.0%) and 21.4% (95% CI: 13.0 - 27.0%) recorded in single infections with trypanosome and nematode, respectively. The Haemonchus contortus (H. contortus ) was the most prevalent nematode parasite of sheep followed by Trichostrongylus species which accounted for 42.0% and 22.0%, respectively. The trypanosome infection was caused predominantly by Trypanosoma (T.) congolense which was responsible for 50.0% of single infection and 25.0% of mixed infection with T. vivax. Concurrent infection invariably resulted in severe anaemia in majority of affected animals which presumably has a serious impact on production. To improve and sustain viable sheep production in the areas, control measures directed against nematode and trypanosome parasites should be considered in tsetse-infested lowland plains in the areas.