Characterization of Pasteurella from gingival scrapings of dogs and cats

Gingival scrapings of 62 dogs and cats were examined for the presence of Pasteurella. Isolation was performed in a medium supplemented with thiostrepton. Twenty-eight and 37 strains were obtained from 21 dogs and 26 cats, respectively, and classified in recently described species or subspecies of the genus Pasteurella (P.): P. multocida subspecies multocida and septica, P. canis, P. dagmatis and P. stomatis. Twenty-one strains were classified as atypical P. stomatis and one strain obtained from a cat remained unclassified. All strains were susceptible to the antibiotics studied. P. multocida and P. stomatis (including atypical strains) represented 65 and 30% of feline isolates, and 14 and 68% of canine isolates, respectively. Assuming that P. multocida, P. canis and P. dagmatis are potentially pathogenic for humans, and that P. stomatis has a low pathogenicity or non-pathogenic, 77 and 28% of examined cats and dogs harboured one or several pathogenic strains. This difference could explain the fact that Pasteurella infections in man are lower in dog bites rather than cat bites.