After 48 h post-challenge, CAT activities increased to 20.11 ± 0.64 U/mL in the prevention group, which was significantly higher than that in the infection group (13.04 ± 0.78 U/mL) and the control group (11.86 ± 0.35 U/mL) (P < 0.01). Here, CAT is linked to infection.