Evidence library

The trust layer behind every conclusion.

Start with what a claim means. Then inspect how direct the evidence is, what limits it, and which sources support or challenge it.

MethodologyEvidence stays multidimensionalSome older source records are still being verified and are not for medical decisions.

Evidence maturity: How far the research has actually progressed for a specific claim.
Evidence directness: Whether the evidence is in dogs, in another species, or mechanistic only.
Safety certainty: How well the risk profile is characterized — separately from efficacy.
Personalized relevance: Whether it applies to this dog, right now, given the profile we hold.
Actionability: Who should be making the decision, and in what setting.
Source status: Source verification and evidence review remain in progress for older records. Those records should not be relied on for medical decisions.
Editorial independence: Inclusion is not endorsement. Commercial relationships must never determine Nara’s conclusions or evidence ratings.

11 of 11 claims

Browse the conclusions, not the database.

Use the filters when you need precision. Each row gives the plain-English claim first and keeps study detail one layer deeper.

TopicSpeciesClassification

Cognitive enrichment

Scent work, problem solving and novel training appear to support cognitive function, mostly studied in older dogs.

Promisingdogsmixed

Enriched environments and continued training are associated with slower cognitive decline in ageing dogs.

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Limitations and sources

Limitations: Mostly older dogs and small samples. Benefits in young adult dogs are inferred, not demonstrated. Full source review pending.

PLACEHOLDER — cognitive enrichment and canine cognitive dysfunction (full source review pending) · Mixed: small trials and observational · Funding: Not yet reviewed

Promisingdogssmall-trial

Scent-based tasks engage dogs with low physical load and are often easier to settle after than high-arousal play.

Limitations and sources

Limitations: Small studies, short follow-up. Full source review pending.

PLACEHOLDER — cognitive enrichment and canine cognitive dysfunction (full source review pending) · Mixed: small trials and observational · Funding: Not yet reviewed

EPA and DHA

Long-chain omega-3 fatty acids have defined canine uses, but effects depend on the actual milligrams consumed.

Established for a defined usedogsrandomised-controlled-trial

Diets supplemented with EPA and DHA improved owner- and vet-assessed mobility in dogs with diagnosed osteoarthritis.

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Limitations and sources

Limitations: Established for dogs with diagnosed joint disease. There is no comparable trial evidence that supplementation prevents joint disease in young, sound dogs, and several trials were industry-funded. Full source review pending.

PLACEHOLDER — omega-3 supplementation trials in dogs with osteoarthritis (full source review pending) · Randomised controlled trials · Funding: Several trials in this area were industry-funded; not yet verified

Promisingdogspharmacological

Effects depend on the actual daily EPA and DHA dose, which many commercial diets and treats do not state clearly.

Limitations and sources

Limitations: Dose–response in healthy dogs is poorly characterised. Full source review pending.

PLACEHOLDER — omega-3 supplementation trials in dogs with osteoarthritis (full source review pending) · Randomised controlled trials · Funding: Several trials in this area were industry-funded; not yet verified

Lean body condition and longevity

Staying lean across life is one of the few interventions with direct, long-term canine outcome data.

Established for a defined usedogscontrolled-cohort

Dogs kept lean throughout life lived longer and developed clinically apparent osteoarthritis later than paired littermates fed more generously.

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Limitations and sources

Limitations: Single long-running study in one breed with a modest number of dogs; the size of the effect in mixed-breed pet dogs is uncertain. Full source review pending.

PLACEHOLDER — lifelong diet-restriction cohort in dogs (full source review pending) · Prospective controlled cohort · Funding: Not yet reviewed

Promisingdogsmethodological

Body condition scoring is a practical owner-usable proxy for adiposity, but it is subjective and observers disagree by roughly one point.

Limitations and sources

Limitations: Scoring reliability varies by training. Full source review pending.

PLACEHOLDER — lifelong diet-restriction cohort in dogs (full source review pending) · Prospective controlled cohort · Funding: Not yet reviewed

Movement and physical activity

Varied loading, balance and low-arousal movement plausibly support musculoskeletal capacity; precise protocols are unproven.

Promisingdogsobservational

More regular physical activity is associated with better measured mobility and lower owner-reported stiffness in adult dogs.

Limitations and sources

Limitations: Observational: active dogs may simply be healthier dogs. Causation is not established. Full source review pending.

PLACEHOLDER — physical activity and canine health outcomes (full source review pending) · Observational · Funding: Not yet reviewed

Mechanistically plausibleotherextrapolated

Varying surface, speed and movement type is expected to load tissues more completely than repetitive flat-ground activity, based mainly on non-canine exercise research.

Limitations and sources

Limitations: Extrapolated from human and rodent work. No canine trial has compared varied versus repetitive movement for long-term outcomes. Full source review pending.

PLACEHOLDER — human and rodent exercise-variation literature used for extrapolation (full source review pending) · Mixed · Funding: Not yet reviewed

Mechanistically plausibledogsmechanism

Repetitive high-arousal retrieving involves rapid deceleration and turning; concern about cumulative load is mechanistic rather than demonstrated.

Limitations and sources

Limitations: No controlled canine data quantify the risk. Full source review pending.

PLACEHOLDER — physical activity and canine health outcomes (full source review pending) · Observational · Funding: Not yet reviewed

Spay and neuter decision-making

Timing trade-offs differ by breed, size and sex; there is no single correct answer for all dogs.

Conflictingdogsretrospective-cohort

Earlier gonadectomy is associated with increased risk of some joint disorders in several larger breeds, while risks and benefits differ by breed, size and sex.

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Limitations and sources

Limitations: Retrospective and breed-specific; results do not generalise cleanly to mixed-breed dogs. Full source review pending.

PLACEHOLDER — gonadectomy timing and joint/neoplastic outcomes by breed (full source review pending) · Retrospective cohort · Funding: Not yet reviewed

Established for a defined usedogsmixed

Spaying removes the risk of pyometra and reduces mammary tumour risk, with the size of the mammary benefit debated.

Limitations and sources

Limitations: Magnitude of the mammary effect is contested and depends on timing. Full source review pending.

PLACEHOLDER — gonadectomy timing and joint/neoplastic outcomes by breed (full source review pending) · Retrospective cohort · Funding: Not yet reviewed