Abstract-only review · 2021
Protein, fibre and fat in diets for dogs after spaying
Diet composition produced clearer changes in faecal measurements than spaying in this experiment.
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.
Ingredients investigated
Multi-ingredient formulations
Medium chain triglycerides oil
Multi ingredient · dog. 28 adult female Beagles: 24 spayed dogs and four sham-operated controls.
Tested form: Medium-chain fats added to high-protein/high-fibre foods, with or without added omega-3; exact MCT source and amount not reported in the reviewed abstract. Dose: Not reported in the reviewed abstract (Food inclusion; amount not reported). Duration: 24 weeks. Comparator: Moderate-protein, moderate-fibre control food.
Measured finding: 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.
Limitations: Only four sham controls. Several nutrients changed together, and food allowance increased halfway through follow-up.
This ingredient was part of a combined formulation; the study does not isolate its contribution.
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.
STU-033. Reviewed 25 September 2026. Next review 25 December 2026.