Compared with the 0 g/kg group, after infection with A. veronii, the activity of SOD in the hepatopancreas of red claw crayfish significantly increased at the 0 h, 24 h, 48 h, and 96 h time points in the 0.1 g/kg, 1.0 g/kg, and 10.0 g/kg groups (p < 0.05), with increases of 14.7%, 19.1%, and 19.0% at 0 h; 4.3%, 8.9%, and 4.2% at 24 h; 5.2%, 12.1%, and 5.1% at 48 h; and 8.2%, 19.3%, and 7.5% at 96 h, respectively. This evidence concerns the gene SOD1 and infection.