White muscle disease (WMD) or Nutritional myodegeneration disease (NMD) is a degenerative disease of the cardiac and skeletal muscles. The level of serum activity of Plasma homocysteine (Hcy), cardiac troponin I (cTn I), Nitric oxide (NO) were investigated in lambs with subclinical NMD in this study. Ten healthy lambs and twenty lambs with subclinical NMD were used in this study. The blood samples were firstly taken at the onset of the disease and then 3 and 10 days after treatment in NMD, and taken once control group. The values of serum activity of creatin kinase (CK), aspartate aminotranferase (AST), alanine aminotranferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were measured with autoanalyzer. Plasma concentration of Hcy, serum cTn I, and levels of NO were determined with ELISA method and value of activity erythrocyte glutathione peroxidase (GSH-Px) was measured with spectrophotometer. Before treatment, values of plasma Hcy, serum NO, cTn I, AST, ALT, ALP, CK, and LDH in lambs with NMD were higher than those of healthy ones (P<0.001), while GSH-Px activity of lambs with NMD are lower than those of healthy (P<0.001). After ten days of treatment, there were no significant differences between treated lambs with NMD and healthy lambs. Nutritional myodegeneration in lambs is associated with increased levels of Hcy, cTn I, and NO. Increased levels of Hcy, cTn I, and NO may be a result of selenium deficiency causing myocardial disorder in NMD lambs.