PREVALENCE AND VARIETIES OF HELICOBACTER SPECIES IN DOGS FROM RANDOM SOURCES AND PET DOGS - ANIMAL AND PUBLIC-HEALTH IMPLICATIONS

Gastric bacteria of a variety of ultrastructural morphologies have bee n identified in or isolated from domestic carnivores, but their preval ence in different populations of animals and their clinical significan ce are still unknown. The purposes of this study were (i) to evaluate the prevalence and morphologic types of gastric bacteria in three diff erent populations of dogs; (ii) to determine which of the organisms we re culturable, and if the cultured organisms mere morphologically simi lar to the organisms seen in situ; (iii) to identify the isolated orga nisms;and (iv) to determine if gastric bacteria were associated with g astritis. Three groups of dogs were examined: healthy laboratory dogs, healthy dogs from an animal shelter, and pet dogs with various nongas tric illnesses. Of these, 100% of laboratory and shelter dogs and 67% of pet dogs were colonized by large, tightly coiled gastric spiral bac teria morphologically similar to Gastrospirillum hominis or Helicobact er felis (referred to as gastrospirilla). Regardless of the presence o r density of gastric bacteria, all of the dogs in the study except one had mild to moderate gastritis. Helicobacter spp. were isolated from only 6 of 39 stomachs cultured, and only three of the organisms isolat ed were morphologically similar to the bacteria seen in situ. Five hel icobacters were identified by 16S rDNA (genes coding for rRNA) sequenc e analysis. Three were strains of H. felis, one was H. bilis, and one was a novel helicobacter morphologically similar to ''Flexispira rappi ni.'' Gastrospirilla are almost universal in the stomachs of domestic dogs, and in most infected dogs, they do not appear to be associated,v ith clinical signs or histologic lesions compared with uninfected dogs . Nongastrospirillum helicobacters are rare in dogs and are not histol ogically detectable. Helicobacter pylori was not isolated from domesti c dogs.