Objective: To determine the Helicobacter spp present in the oral cavity of dogs and the relationship of those organisms with gastric Helicobacter spp to better define the potential for dog-human and dog-dog transmission.
Sample: Saliva and dental plaque from 28 dogs and gastric biopsy specimens from a subset of 8 dogs.
Procedures: PCR-based screening for Helicobacter spp was conducted on samples obtained from the oral cavity of 28 dogs. Comparative analysis was conducted on Helicobacteraceae 16S rDNA clone libraries from the oral cavity and stomach of a subset of 8 dogs (5 vomiting and 3 healthy) that had positive PCR results for Helicobacter spp.
Results: Helicobacteraceae DNA was identified in the oral cavity of 24 of 28 dogs. Analysis of cloned 16S rDNA amplicons from 8 dogs revealed that Wolinella spp was the most common (8/8 dogs) and abundant (52/57 [91%] clones) member of the Helicobacteraceae family in the oral cavity. Only 2 of 8 dogs harbored Helicobacter spp in the oral cavity, and 1 of those was coinfected with Helicobacter heilmannii and Helicobacter felis in samples obtained from the stomach and saliva. Evaluation of oral cavity DNA with Wolinella-specific PCR primers yielded positive results for 16 of 20 other dogs (24/28 samples were positive for Wolinella spp).
Conclusions and clinical relevance: Wolinella spp rather than Helicobacter spp were the predominant Helicobacteraceae in the oral cavity of dogs. The oral cavity of dogs was apparently not a zoonotically important reservoir of Helicobacter spp that were non-Helicobacter pylori organisms.