Zoonoses are defined by the world health organization as diseases and infections which are transmitted naturally between vertebrate animals and human. Undestanding the zoonotic risk posed by pox viruses in companion animals is important for both human and animal health. contagious ecthyma is highly contagious, zoonotic, viral skin disease that affects sheep, goats and some other domesticated and wild animals. In this present study was detected and evaluated levels of plasma paraoxonase activity (PON1), high-density lipoprotein (HDL), total sialic acid (TSA), malondialdehyde (MDA), nitric oxide (NO) and total blood glutathione (GSH) concentrations in healthy sheep and natural infected sheeps with ecthyma. In healthy sheep, laboratory results were determined as PON1 218.54 +/- 17.93 U/L, TSA 59.89 +/- 5.59 mg/dL, HDL 48.4 +/- 4.88 mg/dL, MDA 8.58 +/- 0.80 mu mol/L, NO 7.78 +/- 1.02 mu mol/L and GSH 21.11 +/- 3.70 mg/dL. These values were found 174.92 +/- 18.68 U/L, 70.1 +/- 6.56 mg/dL, 37.9 +/- 6.47 mg/dL, 11.26 +/- 1.06 mu mol/L, 12.44 +/- 1.90 mu mol/L, 7.79 +/- 0.90 mg/dL respectively in sheeps wich are infected by ecthyma. As a result, it was concluded that there is oxidative stress due to imbalance between pro-oxidant and antioxidant molecules in sheep which are infected by ecthyma, and this imbalance is shaped by increasing oxidant levels.