Longitudinal study of diet digestibility, microbiome, and gut fermentation metabolites in growing dogs

Abstract Background Puppies have particular characteristics due to gastrointestinal immaturity, influencing physiological processes. Hypothesis/Objectives Evaluate the effects of age and consumption on apparent diet digestibility coefficients (ADC), fecal characteristics, fermentation metabolites, and fecal microbiome in growing dogs. Animals Eight dogs were evaluated at 2, 5, 8, 11, and 14 months old in experiment 1 and 12 dogs at 14 months old in experiment 2. Methods This was a prospective experimental study. Dietary ADC, fecal characteristics, fermentation metabolites, and fecal microbiome were evaluated in 2 experiments: the first analyzed the effect of age, and the second, the effect of consumption in 2 groups: adult intake (AI) and puppy intake (PI). Results Older dogs had lower ADC of dry matter (DM), ether extract, and metabolizable energy, and higher ADC of crude protein (CP) (P .05). Younger dogs had lower fecal DM and fecal score and higher fecal production (P .05). Older dogs had higher fecal concentrations of short-chain fatty acids and indoles and lower concentrations of branched-chain fatty acids (BCFA) (P .05). Dogs aged between 2 and 5 months had a higher fecal abundance of Streptococcus and Escherichia coli and lower abundance of Turicibacter and Peptacetobacter (P .05). The ADC of DM, organic matter, and CP were lower in PI dogs than in AI dogs (P .05). The AI dogs had higher fecal DM and fecal score and lower fecal production (P .05). Puppy intake dogs had higher fecal concentrations of ammonia and BCFA and a higher abundance of Streptococcus and a lower abundance of Blautia (P .05). Conclusions and clinical importance Age and feed intake influence the ADC of nutrients and energy, the fecal microbiome, and fermentation metabolites, with the microbiota stabilizing after 8 months of age in dogs.