Review scope

This summary is based on the published abstract. We have not appraised the full methods, tables or supplementary material. Details absent from the abstract remain unverified.

Question and design

28 adult female Beagles: 24 spayed dogs and four sham-operated controls. High-protein, high-fibre foods with or without added omega-3 and medium-chain fats; 24-week follow-up. Comparator: Moderate-protein, moderate-fibre control food.

What was measured?

Digestibility, faecal bacteria, metabolites and bile acids.

Main findings

Higher-protein, higher-fibre foods produced larger decreases in energy and organic-matter digestibility and larger increases in faecal short-chain fatty acids. Microbial composition also differed.

Study strengths

Baseline measurements and repeated follow-up; random dietary allocation among spayed dogs.

Limitations

Only four sham controls. Several nutrients changed together, and food allowance increased halfway through follow-up.

Researchers’ conclusion

The authors attributed most measured differences to diet, with smaller effects of surgery.

Evidence.pet interpretation

This does not isolate a benefit from fish oil, MCT or fibre alone, nor establish that microbial changes prevent weight gain.

Funding and conflicts

Not verified from the abstract; full declarations have not been reviewed.

Source and review date

Phungviwatnikul T et al. Dietary macronutrient profiles, digestion and faecal measurements after spay surgery. Journal of Animal Science. 2021. Title shortened; PMID 34333604 identifies the paper.

Read the primary source

STU-033. Reviewed 25 September 2026. Next review 25 December 2026.