Marketing a diet as functional and therapeutic is one thing but proving it requires empirical evidence. Research published in the American Journal of Veterinary Research aimed to provide evidence to back up one of pet food’s most popular claims. The study evaluated whether a dry, extruded diet designed for dogs with gastrointestinal conditions could improve apparent digestibility, metabolizable energy, palatability, fermentative metabolites and fecal microbiota compared with a standard adult maintenance diet. While the dogs in the trial were healthy, the authors framed the work as a step toward understanding how such diets might support dogs with gastrointestinal disorders.
“Providing a highly digestible and palatable diet with functional ingredients may contribute to the treatment of gastrointestinal disorders of dogs,” the study authors wrote.
The researchers used 16 healthy, 1-year-old Beagles housed at a university research facility in Brazil. All dogs consumed a control adult maintenance diet for 20 days. After that period, eight dogs were switched abruptly to the therapeutic gastrointestinal diet, while eight remained on the control diet for an additional 35 days. Fecal samples were collected at multiple time points to assess pH, metabolites and microbiota, and a total fecal collection was conducted to calculate nutrient digestibility and metabolizable energy.
Effects of switching to therapeutic dog food
Dogs fed the therapeutic diet showed higher apparent digestibility coefficients for all measured nutrients, including protein, fat and energy, compared with dogs fed the control diet. The therapeutic diet also delivered higher metabolizable energy, while dogs consumed less dry matter overall. These changes resulted in lower daily fecal output and higher fecal dry matter, indicators often associated with improved stool quality and digestive efficiency.
Fecal pH was lower in dogs fed the therapeutic diet, and concentrations of total short-chain fatty acids, including butyrate, were higher. According to research results published in the journal, fecal butyrate increased as early as three days after dogs switched to the therapeutic diet and remained elevated through day 30. Butyrate is widely recognized for its role in supporting intestinal epithelial health and moderating inflammation.
The fecal microbiome also shifted rapidly following the diet change. Beta-diversity analysis showed distinct microbial profiles between dogs fed the therapeutic and control diets by day three. Dogs consuming the therapeutic diet had greater relative abundance of Faecalibacterium and Turicibacter, bacterial genera commonly associated with intestinal balance, and lower abundance of Streptococcus, which has been linked to intestinal problems in dogs.
Palatability testing at the end of the study showed that dogs preferred the therapeutic gastrointestinal diet, consuming a significantly greater proportion of it when offered alongside the control diet.
Although the study was conducted in healthy dogs, the authors concluded that a highly digestible, palatable diet containing functional fibers, oils and microbial ingredients can beneficially modulate fecal metabolites and microbiota. They noted that further studies in dogs with clinical gastrointestinal disease are needed to confirm whether these physiological changes translate into measurable clinical benefits.
