AUTHOR=Legesse Simegn , Hailemelekot Mussie , Tamrat Habtamu , Alemu Yeshwas F. 

TITLE=Epidemiological and therapeutic studies on sheep lice in Sayint district, South Wollo Zone, Northeast Ethiopia

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.1008455

DOI=10.3389/fvets.2022.1008455

ISSN=2297-1769

ABSTRACT=An epidemiological (cross-sectional) and therapeutic (randomized controlled field trial) study was conducted on sheep lice in Sayint District, South Wollo, Ethiopia. The aim of the study was to: i) quantify the magnitude of sheep lice burden and the prevailing lice species, ii) identify and quantify risk-factors affecting lice infestation in sheep and, iii) evaluate the efficacy of commonly used acaricides (diazinon and ivermectin) against sheep lice infestation. A total of 232 randomly selected sheep, 15 naturally infested sheep and 80 viable Bovicola ovis lice were used for epidemiological, in-vivo and in-vitro based therapeutic study, respectively. Three naturally infested treatment groups (Group I- treated with diazinon, Group II- treated with ivermectin and Group III- untreated/control) were used for in-vivo therapeutic study. Lice count for the corresponding treatment groups was conducted on weekly basis using clinical and parasitological examinations. Logistic regression was used to quantify the association between different putative risk factors and lice infestation and, independent t-test and one-way ANOVA were employed to compare the with-in and between treatment group mean lice count variations. The overall prevalence of sheep lice in the study area was 48%, where Bovicola ovis (83%) was the dominant lice species. Hair length (OR=2, P=0.00), body condition (OR=1.9, P=0.02), agro ecology (OR=1.19, P=0.00) and season (OR=2, P=0.01) were significantly (P<0.05) associated with sheep lice infestation. Analysis of variance revealed that mean lice count was significantly (P<0.05) different between treatment groups. A significant (P<0.05) low mean lice cunt was recorded in diazinon and ivermectin treated groups when compared to untreated group. The in-vivo efficacy of ivermectin (81%) was lower than diazinon (99%) when compared to the efficacy set-limit standards (98-100%. However, no significant mean lice count variation was recorded between the two groups. In-vivo (99%) and in-vitro (99%) assay evidences revealed that diazinon was highly effective for the treatment of sheep lice. Inconclusion, the magnitude of sheep lice burden in Saint district was found to be high and this could have a potential impact on sheep productivity and health performances. Thus, applying an appropriate intervention measure is warranted