Zin en onzin van het onderzoek van fecesstalen van honden met diarree op de aanwezigheid van Escherichia coli

Bacteriological examination of fecal samples from diarrheic dogs invariably results in the isolation of Escherichia coli. The association of the presence of this bacterium with enteric disease in dogs is not clear. In this study, the association between the presence of E. coli virulence genes and diarrhea in dogs was confirmed. For this purpose, E. coli isolates recovered from the feces of 34 healthy dogs and 25 dogs with diarrhea aged 7.5 months to 10 years, were tested for the presence of 17 virulence genes. Virulence genes were not detected in 15 of the 25 and 15 of the 34 isolates from dogs with or without diarrhea, respectively. In the other isolates, the presence of genes encoding the toxins cytotoxic necrotising factor (CNF) 1, CNF2, verotoxin (VT) 1 and VT2 and/or the adhesins intimine, F5 fimbriae and F41 fimbriae was demonstrated. There was, however, no significant difference in the prevalence of virulence genes between E. coli isolates from the diarrheic and non-diarrheic adult dogs examined. Because diagnostic markers in the E. coli isolates are absent, the examination of canine feces on the presence of this bacterium is of little diagnostic value.