Int J Biol Sci 2022; 18(13):5086-5102. doi:10.7150/ijbs.72770 This issue


From Chihuahua to Saint-Bernard: how did digestion and microbiota evolve with dog sizes

Charlotte Deschamps1,2, Delphine Humbert3, Jürgen Zentek4, Sylvain Denis1, Nathalie Priymenko5, Emmanuelle Apper2, Stéphanie Blanquet-Diot1✉

1. Université Clermont Auvergne, UMR 454 MEDIS UCA-INRAE, Clermont-Ferrand, France
2. Lallemand Animal Nutrition, Blagnac, France
3. Dômes Pharma, Pont-du-Château, France
4. Institute of Animal Nutrition, Freie Universität Berlin, Königin-Luise-Strasse 49, Berlin, Germany
5. Toxalim (Research Center in Food Toxicology), University of Toulouse, INRAE, ENVT, INP-Purpan, UPS, Toulouse, France

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Deschamps C, Humbert D, Zentek J, Denis S, Priymenko N, Apper E, Blanquet-Diot S. From Chihuahua to Saint-Bernard: how did digestion and microbiota evolve with dog sizes. Int J Biol Sci 2022; 18(13):5086-5102. doi:10.7150/ijbs.72770. Available from

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Graphic abstract

Health and well-being of dogs are of paramount importance to their owners. Digestion plays a key role in dog health, involving physicochemical, mechanical and microbial actors. However, decades of breeding selection led to various dog sizes associated with different digestive physiology and disease sensitivity. Developing new products requires the consideration of all the multi-faceted aspects of canine digestion, the evaluation of food digestibility, drug release and absorption in the gut. This review paper provides an exhaustive literature survey on canine digestive physiology, focusing on size effect on anatomy and digestive parameters, with graphical representation of data classified as “small”, “medium” and “large” dogs. Despite the huge variability between protocols and animals, interesting size effects on gastrointestinal physiology were highlighted, mainly related to the colonic compartment. Colonic measurements, transit time permeability, fibre degradation, faecal short-chain fatty acid concentration and faecal water content increase while faecal bile acid concentration decreases with body size. A negative correlation between body weight and Proteobacteria relative abundance was observed suggesting an effect of dog body size on faecal microbiota. This paper gathers helpful in vivo data for academics and industrials and supports the development of new food and pharma products to move towards canine personalized nutrition and health.

Keywords: canine, digestive physiology, gut microbiota, petfood, veterinary products