Description of the bacterial microbiota of anal sacs in healthy dogs.

The aim of the present study was to characterize the bacterial microbiota of anal sacs in healthy dogs using NGS. Swabs were used to sample the rectum and secretions from each anal sac in 15 healthy dogs. DNA was extracted from swabs and the V4 hypervariable region of the 16S rRNA gene was amplified and sequenced with Illumina MiSeq. Overall, 14 different bacterial phyla were identified in the rectum and in both anal sacs, the 5 main ones being Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, and Fusobacteria. The rectum had higher microbial diversity and richness than the left and right anal sacs. Community membership and structure significantly differed between the rectum and both anal sacs, but not between the right and the left anal sacs. This study showed that the diversity and richness of the bacterial microbiota of the anal sacs in dogs is greater than what has been reported in previous studies with culture-based methods. In conclusion, the bacterial microbiota of the anal sacs in dogs varies between individuals and differs from the rectal bacterial microbiota.