Can your dog's stools tell you whether its food is working?

Partly. Well-formed, regular stools of modest volume point to good digestive tolerance and decent digestibility. But stools say nothing about nutritional balance or quality control. They are a useful indicator, not a proof of overall quality (Tufts Petfoodology, 2023).

What stools genuinely reveal

Stool quality reflects the digestibility and digestive tolerance of a food. High digestibility leaves fewer residues, so the stools are more compact and less bulky (Tufts Petfoodology, 2023). Bulky or loose stools can flag lower digestibility, an excess of fibre [fiber] or a transition made too fast. The striking part for a curious owner: a highly digestible food can noticeably shrink stool volume at a comparable amount eaten, which is one reason makers and vets watch this sign closely.

The limits of this indicator

Stools say nothing about whether needs are met, whether a board-certified nutritionist was involved, or how tightly quality is controlled (WSAVA, 2021). A food can produce handsome stools while being unbalanced over the long run. Passing diarrhoea [diarrhea] during a food change usually belongs to the transition, ideally spread over 7 to 10 days, rather than to a fault in the product (FEDIAF, 2021). Persistently abnormal stools call for a veterinary opinion.