ADA and Diarrhea: The measurements of salivary ADA activity showed significantly higher activity levels in pigs with diarrhoea caused by E. coli (median 2712 U/L, minimum–maximum range 1293–19936 U/L) compared with healthy pigs (median 881.6 U/L, minimum–maximum range 60.8–2435 U/L) (p < 0.001) (Figure 3).