This study was performed to reveal the changes in certain serum biochemical parameters in animals diagnosed with Cystic Echinococcosis. The material of the study consisted of 40 sheep aged 1-3, which were brought for slaughter from different animal farms of Siirt. Overall, 20 sheep which were determined to be healthy in physical examinations and had no pathological lesions in their internal organs were determined as the control group, while the remaining 20 sheep with cystic lesions in their lungs and livers which were protoscolex-positive formed the infected group. While no significant relevant difference between the K, Cl., Ca, Mg, GGT, ALT, ALB, TRIG. and CHOL levels of health and infected animals (1)>0.05), statistically meaningful changes in Na (p<0.01). TBIL (p<0.05), and TP and GLOB (p<0.001) levels and AST (p<0.001) activity were observed between the groups. As a result, it was determined that the changes in AST, total protein, globulin, and total bilirubin levels could be used as supportive laboratory analyzes in a determination of the prognosis of animals infected with Cystic Echinococcosus and of the physiopathologic alterations occurring in their livers.