Epidemiology of Small Ruminant External Parasites: In the Case of Chemical Control Campaign in Welkait District, Tigray Region, Ethiopia

A cross-sectional study and simple random sampling technique was conducted to determine the epidemiology of major external parasites and associated risk factors in small ruminants in Welkait, Western part of Tigray from November 2015 to may 2016. The collected data was analyzed using STATA 11.1stastical soft ware and descriptive statistics, percentages and 95% confidence intervals were used to summarize the proportion of infested and non-infested animals. Out of the 102 sheep and 324 goats clinically examined, 75(73.53%) sheep and 246 (75.93%) goats were found to be infested with one or more external parasites. The rate of different external parasite infestations revealed that a prevalence of 71(69.61%) hard ticks and 7(6.86%) fleas were observed in sheep, whereas 211(65.12%) hard ticks, 84(25.93%) lice, 60(18.52%) fleas and 4(1.23%) mange species was recorded in goats. Statistically significant variation (P< 0.05) was found in the cases of lice and flea between the two species. Even though there were differences in prevalence of lice and flea between different risk factors, the difference in prevalence was not statistically significant (P>0.05) in goats except in the case of lice by body condition score and flea by agro-ecology and age, respectively. Tick infestation in goats, statistically associated with agro-ecology, body condition, age, and flock type of the animal studied, whereas most risk factor considered were not significantly significant (P>0.05) in sheep except in the case of ticks, by agro-ecology and flea by the age of sheep. The prevalence of lice was 2.936 and 2.159 times higher in poor and medium body conditions (P<0.05) than in good body conditions of goats respectively, where as in the case of flea, goats in high land were 2.600 more likely (P<0.05) to be infected by flea than goats in low land, respectively. Young age goats are 3.73 times more likely to be infested by fleas than adults. Similarly, tick’s in goats in highland and midland agro-ecology were 6.498 and 5.200 times more infested by tick than lowland, respectively and 0.335, 2.187, 4.828 and 3.101 times adults than young, mixed than single rearing and goats being poor and medium body conditions than in good body conditions, respectively. Sheep living in highland were 4 times higher in harboring ticks than lowland. The species level logistic analysis result indicated that goats were 3.084 times more infested by fleas than sheep.