Introduction: Annually, hydatid cyst causes great economic losses to communities and farmers. Hydatidosis in livestock results in a significant decrease in livestock production and seizure of infected organs of the animals at slaughterhouses. Thus, this study aimed to investigate the pollution rate of hydatid cyst in slaughtered livestock in Asadabad Slaughterhouse during the period of 2014-2015

Methods: In this cross-sectional analytic-descriptive study, by using the simple random sampling a total of 4000 cattle: 4000 sheep and 4000 goat from November 2014 to October 2015 were selected to be studied via the macroscopic method clinical examination cutting the organ under study and checklist completion. The data were analyzed by SPSS-21 using the Chi-square test.

Results: The prevalence of hydatid cysts in livestock was 10.7%. Sheep were the most infected (16.38%) and goats were the least infected (1.9%).The females were more infected than the males (P<0.001). The highest and lowest rates of infection were observed in spring and winter, respectively (P<0.003). In sheep, the fertility of hydatid cysts in liver (77%) was more than lung (47.05%), whereas in calves the fertility of hydatid cysts in lung (43.45%) was more than liver (33%).

Conclusion: Considering the relatively high prevalence of hydatid cyst in slaughtered livestock of Asadabad, causing great losses for farmers and the presence of canines in polluted areas and the life cycle of the parasite, the risk of disease transmission to human is high in these areas. Therefore, the importance of health issues of slaughtered livestock should be taken very seriously.