Variations in facial conformation are associated with differences in nasal microbiota in healthy dogs.

Background: Extrinsic and intrinsic factors have been shown to infuence nasal microbiota (NM) in humans. Very
few studies investigated the association between nasal microbiota and factors such as facial/body conformation, age,
and environment in dogs. The objectives are to investigate variations in NM in healthy dogs with diferent facial and
body conformations. A total of 46 dogs of diferent age, living environment and from 3 diferent breed groups were
recruited: 22 meso−/dolichocephalic medium to large breed dogs, 12 brachycephalic dogs and 12 terrier breeds. The
nasal bacterial microbiota was assessed through sequencing of 16S rRNA gene (V1-V3 regions) amplicons.
Results: We showed major diferences in the NM composition together with increased richness and α-diversity in
brachycephalic dogs, compared to meso−/dolichocephalic medium to large dogs and dogs from terrier breeds.
Conclusion: Healthy brachycephalic breeds and their unique facial conformation is associated with a distinct NM
profle. Description of the NM in healthy dogs serves as a foundation for future researches assessing the changes
associated with disease and the modulation of NM communities as a potential treatment.