[en] This manuscript reviews the current knowledge on the main classes of pathogenic Escherichia coli in dogs and cats: type 1 necrotoxigenic strains (NTEC1), adhesin-positive strains (AdEC), enteropathogenic strains (EPEC) and enterotoxigenic strains (ETEC). They represent primary or secondary (to other bacterial, parasitic and/or viral infections) infectious agents. NTEC1 and AdEC are the most frequent and are responsible for intestinal, urinary tract and invasive infections, while EPEC and ETEC limit their infections to the intestinal tract. ETEC are the less frequent but EPEC are more and more often observed. The specific virulence factors and other properties of these pathogenic E. coli strains are similar to those of their bovine, human and porcine counterparts, for their identity and their genetic determinism. This similarity allows the use of an identical approach in their diagnosis and typing. But for some NTEC1, AdEC and EPEC strains the similarity is so close that it also raises the question of their zoonotic potential, though there is up to now no epidemiological evidence of such cross contamination of man by canine or feline pathogenic E. coli (or vice versa).