Fecal samples from 720 healthy, domestic animals representing seven different species (cattle, sheep, goats, pigs, chickens, dogs, and cats) were investigated for verotoxin (VT [Shiga-like toxin])-producing Escherichia coli (VTEC). VTEC were isolated from 208 animals (28.9%), most frequently from sheep (66.6% VTEC carriers), goats (56.1%), and cattle (21.1%). VTEC were isolated less frequently from pigs (7.5%), cats (13.8%), and dogs (4.8%) and were not found in chickens (< 0.7%). Forty-one different O:H serotypes and 23 untypeable O-groups were isolated. Five serotypes (O5:H-, O91:H-, O146:H21, O87:H16, and O82:H8) occurred in more than one animal species. Serotypes O5:H-, O91:H-, O146:H21, O128:H2, and OX3:H8 represented 54.8% of the VTEC strains. Nearly 60% of all VTEC O:H serotypes isolated in this study have been implicated as human pathogens, indicating that healthy, domestic animals may serve as a reservoir of human pathogens. All VTEC, except nine feline strains, hybridized with one or both of the VT1 and VT2 specific DNA probes. VT production and enterohemolysin (E-Hly+) production were associated in E. coli from goats, sheep, and cattle but not in E. coli from chickens, pigs, dogs, and cats. A close association of VT with E-Hly+ was found in O5:H-, O146:H21, O128:H2, O77:H4, O119:H25, and O123:(H10) strains. Thirty of 240 (12.5%) E-Hly+ strains hybridized with an E-Hly+ specific DNA probe, indicating heterogeneity of regulatory or structural E-Hly+ genes in strains of E. coli.