This study was conducted aiming at knowing the pathological changes that are concomitant with natural infection of
hydatidosis in sheep, goat and cattle, in addition to estimate, if infection has relations with oxidative stress via estimation of the
total antioxidants and oxidants in hydatid fluid. Results of the present study elucidate the presence of chronic histopathological
lesions represented by hemorrhage and vascular changes, hepatic programmed cell death, portal fibrosis, infiltration of
inflammatory cells around hydatid cysts in addition to necrosis, collection of hydatid fluid from 25 samples (each one) for
estimation of total Antioxidants and total oxidants in hydatid fluid. Results showed total antioxidants level in fertile cysts
higher than in sterile cysts, and there was no significant variation in total oxidants of fertile and sterile cysts.