Epidemiological study on manage mite, lice and sheep keds of small ruminants in Tigray region, northern Ethiopia

Tigray Region used to be an important source of hides and skins in Ethiopia. However, today the quality and quantity have significantly declined, for which external parasites are incriminated as major causes. Epidemiological study on mange mite, lice and sheep keds of small ruminants was conducted, from Feb.-Aug./2003, with the objectives of determining the distribution and the major risk factors associated with the external parasites. A total of 43,325 animals (22,337 sheep and 20,988 goats), from lowland, medium and high altitudes, were clinically inspected, for the parasites during the dry and wet seasons. The prevalence rate of mange mite was 8.11% (95% CI 4.2284-4.6179) and 0.95% (95% CI 0.8303-1.0898) for goat and sheep, respectively. Goats were 9.17 (OR=9.17, 95% 7.92-10.61) times at higher risk of acquiring mange mite infestation than sheep. Statistically significant difference (X2=121, P=0.0000) was observed during the dry (5.68%) and wet (3.48%) seasons which was associated with seasonal feed shortage and other stress factors. Animals in lowland were 2.63 (OR=2.6, 95% 2.15-3.20) times more exposed to mange mite infestation than the highland. The prevalence of lice infestation in goats was 11.98% (95% CI 11.5466 -12.4301). During the dry season, animals were exposed to lice infestation 2 times (OR=2.18, 95% 1.51-1.77) more than in the in wet season. Statistically significant difference (P<0.05) in lice infestation was recorded between lowland (6.89%) and highland (3.75%), < 1 year age (7.19%) and >2 years (5.53%) and male (8.3%) and female (5.28%). The Overall prevalence of sheep keds was 11.67%. (95% CI 13.8833-16.0302) Statistically significant difference (P<0.05) was also observed between highland (19.48%) and lowland (1.84%). Sheep in the highland were 13 times more at higher risk of acquiring sheep keds infestation than those in the lowland (OR=12.9,95% CI, OR 10.77-15.44). Finally animal species, agro climatic conditions and seasons were the main risk factors considered during the study of the epidemiology, a knowledge which should be incorporated during control measures.