The aim of this study was to investigate the prevalence of STEC and EPEC strains and E. coli O157 serogroup in some Equidae and Canidae. The fecal samples of 79 animals from 6 different species were evaluated for presence of these strains. All the Isolates were tested for virulence genes using multiplex-PCR. Non-sorbitol fermenting (NSF) Escherichia coli isolates and positive strains for virulence factors were subjected to serogroupe specific PCR for rfb O157 gene. None of the STEC, EPEC and NFS strains in this study belonged to O157 serogroupe. While 36.64% of animals carried strains positive for one or more of the virulence factors tested, and 18.9% of animals harbored STEC strains (stx1), stx2 was not detected in this study. eae and Ehly positive strains were found in 3.79% and 22.7% of animals respectively. In conclusion, these species can act as a reservoir for EPEC and STEC strains. Also, since the study was conducted in some parts of Iran, a more accurate conclusion needs more distributed sampling. To our knowledge this is the first study which reports the faecal shedding of STEC and EPEC from wild captive Canidae and Equidae in Iran.