The aim of this study was to determine the diagnostic importance of erythrocyte glutathione peroxidase activity (GSH-Px) in lambs with white muscle disease (WMD) and the changes in some serum parameters (glucose, creatinine, total protein, albumin. cholesterol, triglyceride, Ca, inorganic P. Na, K, Cl, AST, ALT, ALP, LDH and CPK) in healthy and white muscle diseased lambs