When a panel of cytokines (including GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α) was measured in saliva from healthy pigs and in pigs with meningitis and S. suis infection, upregulation of several cytokines was observed in the diseased animals. This evidence concerns the gene IL4 and infectious meningitis.