Pet Evidence PROJECT

Last updated May 5, 2026

Supplement Review

Fish oil (Omega-3)

for Cognitive Function in Dogs

Omega-3 supplementation may improve signs of cognitive decline in adult dogs, though evidence is limited.

Prepared by the Pet Evidence Project editorial team.

Fish oil (Omega-3) supplement ingredients

Limited Evidence

Few smaller trials, often in combination with other compounds.

About our grading system

Evidence Snapshot

  • Best supported for

    Cognitive function

  • Evidence quality

    Low

  • Amount of research

    Limited

  • Safety

    Low risk

  • Observed benefit

    Limited Evidence

Evaluated for dogs across 6 peer-reviewed references.

Evidence Review (Deep Dive)

Explore the science behind the evidence. Each section expands to reveal the full review.

Does supplementation with omega-3 fatty acids improve signs of cognition in adult dogs with signs of early cognitive dysfunction?

Full scientific review The full scientific review, including evidence, safety, and practical context.

Omega-3's for Canine Cognition: The Background and Evidence Explained

Omega-3 fatty acids, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), serve as essential structural and functional components of the central nervous system. In the context of the aging brain, a decline in polyunsaturated fatty acid (PUFA) concentrations may be associated with the progression of Canine Cognitive Dysfunction Syndrome (CCDS). DHA is a primary structural lipid in neurons where it assists with many important functions(Araujo et al., 2022). The pathophysiology of CCDS involves chronic neuroinflammation and oxidative stress, which lead to the degradation of these vital lipids(Blanchard et al., 2025). Omega-3 supplementation may help to address these changes by increasing the levels of neuroprotective metabolites, such as neuroprotectin D1, which help to suppress pro-inflammatory cytokines and mitigate the neuronal apoptosis (cell death) triggered by beta-amyloid accumulation(Welty, 2023).

Pharmacologically, the efficacy of omega-3s is highly dependent on dosage and timing, with recent systematic reviews suggesting that benefits are most pronounced when supplementation begins in the early stages of cognitive decline(Vendramini et al., 2025). Clinical trials in aged Beagle dogs have demonstrated that diets enriched with fish oil or oil-rich algae may improve visuospatial function, shape discrimination, and executive performance(Pan et al., 2018a). These effects are often synergistic; omega-3s are frequently administered alongside antioxidants like Vitamin E and C, which protect the unstable fatty acids from oxidation and enhance their anti-inflammatory potential(Blanchard et al., 2025).

Omega-3’s were primarily studied when administered in combination with other compounds, likely indicating a multi-modal approach may be more effective than an individual agent alone(Pan et al., 2018b). There is a hypothesized benefit to combining omega-3’s with CoQ10, a potent antioxidant and important component of mitochondria. Using these in combination may provide a comprehensive approach to mitochondrial membrane stabilization and protection from oxidative stress, a known contributor to progression of cognitive dysfunction. These currently remain theories and further clinical trials are required for evidence-based recommendations.

The Bottom Line

There was a trend of a mild benefit of omega-3’s on the improvement of cognition, though often in the context of combined products. Few studies compared the clinical effects of omega-3 supplementation in the setting of cognitive dysfunction. Most studies evaluated multiple compounds at the same time (blends), making it difficult to distinguish the individual effects of omega-3’s from other compounds. Many studies were funded by manufacturers of products, imparting a high risk of bias. Multiple laboratory studies and human clinical trials have found mild benefit in the setting of cognitive dysfunction, thus contributing in vitro and possibly translational evidence to support the theoretical benefit of omega-3 supplementation for cognitive dysfunction.

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Key References

6 peer-reviewed studies
  1. 1

    Araujo JA, Segarra S, Mendes J, et al.. Sphingolipids and DHA Improve Cognitive Deficits in Aged Beagle Dogs (opens in a new tab) . Front Vet Sci. (2022).

  • Evidence first

    We evaluate ingredients based on the quality and consistency of scientific evidence.

  • Veterinarian-authored

    Content is written or reviewed by board-certified veterinary professionals.

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