Detection of Antibodies to Erysipelothrix in Stray Dogs in Japan

Erysipelothrix rhusiopathiae is considered as a pathogenic bacterium for many species of animals. The genus Erysipelothrix had been thought to contain a single strain. However, on the basis of genetic homology, the genus Erysipelothrix was found to constitute different strains, E. rhusiopathiae and a new strain, E. tonsillarum (Takahashi et al. 1992). E. tonsillarum can be distinguished from E. rhusiopathiae by serology, the fermentation of saccharose, genetic homology and the lack of pathogenicity for pigs (Takahashi et al. 1992, 1993, 2000a). The classical host of the bacterium is the pig, but it can also induce a wide variety of disease conditions in other mammals and birds (Kucsera 1979, Takahashi et al. 1994). The bacterium has been isolated from dogs with endocarditis (Eriksen et al. 1987, Hoenig & Gillette 1980, Kucsera 1979, Sisson et al. 1984). In an experimental infection study using an isolate from a dog, it was confirmed that dogs developed endocarditis after intravenous inoculation (Goudswaard et al. 1973). The isolates from dogs with endocarditis in Belgium were typed as serovar 7, which is one of the E. tonsillarum serovars (Schrauwen et al. 1993, Takahashi et al. 1993). Furthermore, the isolate was classified into genomic E. tonsillarum based on the characteristics and genetic homology (Takahashi et al. 2000a). Other strains isolated from several cases of erysipelas in dogs were also typed as serovar 7 (Hoenig & Gillette 1980). These reports strongly indicated that E. tonsillarum was a canine pathogen. However, there is no information about serological surveys in dogs to elucidate the epidemiological features of the disease in the field. Furthermore, there are few studies about the mechanism of erysipelas in dogs. As a causative factor of bacterial endocarditis, a pre-existing heart lesion has been suspected, but the relation between them is still obscure (Goudswaard et al. 1973, Hoenig & Gillette 1980). It has not been documented, whether erysipelas is actually caused by the mixed infection with Erysipelothrix and other organisms in dogs. In this study, to search for the epidemiological features of erysipelas infection among dogs, we surveyed the levels and the distribution of antiErysipelothrix antibodies among dogs in the field. The serum samples used in this study were obtained from 120 stray or homeless dogs in Acta vet. scand. 2005, 46, 159-161.