Recent molecular studies have revealed a highly complex bacterial assembly in the canine intestinal tract. There is mounting evidence that microbes play an important role in the pathogenesis of acute and chronic enteropathies of dogs, including idiopathic inflammatory bowel disease (IBD). The aim of this study was to characterize the bacterial microbiota in dogs with various gastrointestinal disorders. Fecal samples from healthy dogs (n = 32), dogs with acute non-hemorrhagic diarrhea (NHD; n = 12), dogs with acute hemorrhagic diarrhea (AHD; n = 13), and dogs with active (n = 9) and therapeutically controlled idiopathic IBD (n = 10) were analyzed by 454-pyrosequencing of the 16S rRNA gene and qPCR assays. Dogs with acute diarrhea, especially those with AHD, had the most profound alterations in their microbiome, as significant separations were observed on PCoA plots of unweighted Unifrac distances. Dogs with AHD had significant decreases in Blautia, Ruminococcaceae including Faecalibacterium, and Turicibacter spp., and significant increases in genus Sutterella and Clostridium perfringens when compared to healthy dogs. No significant separation on PCoA plots was observed for the dogs with IBD. Faecalibacterium spp. and Fusobacteria were, however, decreased in the dogs with clinically active IBD, but increased during time periods of clinically insignificant IBD, as defined by a clinical IBD activity index (CIBDAI). Results of this study revealed a bacterial dysbiosis in fecal samples of dogs with various GI disorders. The observed changes in the microbiome differed between acute and chronic disease states. The bacterial groups that were commonly decreased during diarrhea are considered to be important short-chain fatty acid producers and may be important for canine intestinal health. Future studies should correlate these observed phylogenetic differences with functional changes in the intestinal microbiome of dogs with defined disease phenotypes.

This study evaluated the fecal microbiota of 12 healthy pet dogs and 12 pet cats using bacterial and fungal tag-encoded FLX-Titanium amplicon pyrosequ

The effect of a proton pump inhibitor on gastrointestinal (GI) microbiota was evaluated. Eight healthy 9-month-old dogs (four males and four females)

The effect of a multi-species synbiotic on the fecal microbiota of healthy cats (n= 12) and dogs (n= 12) was evaluated. The synbiotic (containing 5 ×

Temporal variations of intestinal microorganisms have been investigated in humans, but limited information is available for other animal species. The aim of the study was to evaluate the abundance and short‐term temporal variability of fecal microbiota in dogs. Two fecal samples were collected (15 days apart) from six healthy dogs. The microbiota was evaluated using fluorescence in situ hybridization (FISH) and 454‐pyrosequencing targeting the 16S rRNA and its gene. Pyrosequencing revealed 15 families comprising >80% of all microbiota, over time intraindividual coefficients of variation (%CV) ranged from 2% to 141% (median: 55%). In contrast, the interindividual %CV ranged from 62% to 230% (median: 145%). Relative proportions of Faecalibacterium (important for intestinal health) and Subdoligranulum were low (two dogs harbored 4–7% of Subdoligranulum, the remaining dogs had <1% of either genus). Conversely, FISH revealed that Faecalibacterium comprised a median of 5% of total counts (range: 0–8%, probe Fprau645). A novel FISH probe (Faecali 698) was tested that, compared with Fprau645, can detect in silico a similar percentage of Faecalibacterium but higher proportions of Subdoligranulum. This probe revealed a high percentage of Faecalibacterium–Subdoligranulum (median: 16% of total counts). Future studies should consider the observed variability and discrepancies in microbial abundance between FISH and 454‐pyrosequencing.