Cryptosporidium spp. and Giardia spp. antigens were detected by chromatographic immunoassay (Oxoid, Basingstoke, UK). The presence of Eimeria spp. was examined by flotation technique using saturated saline [25] . E. coli and C. perfringens were isolated according to the protocol reported by Quinn et al. [2] . E. coli hemolytic activity was evaluated by growing colonies on blood agar base, while virulence factors (lt-heat-labile toxin, st-heatstable toxin, stx1-Shiga toxin 1, stx2-Shiga-toxin 2, eaeintimin, cnf-cytotoxic necrotizing factor, and cdt-cytolethal distending toxin) were detected by molecular assays, as previously reported [26] [27] [28] .