Our study revealed a significant increase in mean serum cTn-I in FMD-infected calves (< 2 months) with clinical signs suggestive of myocarditis (A1: 11.65 ± 0.34) than those (< 2 months and > 2 months < 4 months) without clinically suggestive of myocarditis (A2: 0.06 ± 0.00 and B1: 0.052 ± 0.002) and healthy control groups (C: 0.0466 ± 0.005 and D: 0.0466 ± 0.004). The gene discussed is TNNI3; the disease is myocarditis.