During a three-year period (1987 & 1990), a comprehensive attempt was made to isolate verocytotoxin-producing Escherichia coli (VTEC) from 96 bovine, 89 porcine, 67 canine and 18 feline cases suffering from gastroenteritis. VTEC were isolated from 11 cows and 1 cat. Bead-ELISA and oligonucteotide probes were used to type the verotoxins (VT) and it was found that the VTEC strains from cows produced not only the currently recognized VT1, VT2 and VT2vh but also produced two new VT's tentatively designated as VTx and VTy. The strain from the cat produced VTy. Serotyping of the strains revealed that some animal strains belonged to similar serotypes as those isolated from human patients with hemorrhagic colitis and hemolytic uremic syndrome. Cattle, especially cows, and domestic pets apparently are reservoirs of VTEC and probable sources of infection in our country as has been previously documented in Canada and USA.