IL18 and infection: The results showed that serum IL-18 in PG-treated WT mice was obviously higher than in infection-only WT mice, but there was no significant difference in IL-18 production between N. caninum-infected Nlrp3−/− mice with or without PG treatment, and IL-18 production in Nlrp3−/− mice induced by PG treatment was lower than the production in the corresponding WT mice (WT: F(2, 12) = 76.96, P < 0.0001; Nlrp3−/−: F(2, 12) = 0.615, P = 0.5566; Fig. 5e).