PuppyweeksSources
Last reviewed 5 August 2026
Puppyweeks' developmental content — the stage-by-stage guidance Copilot works from too — is grounded in established canine behavioural science, not generic advice. Here's what it's built on.
The foundational research
Scott & Fuller, Genetics and the Social Behavior of the Dog (1965) — a 13-year longitudinal study that identified the critical periods of puppy development, including the socialisation window (weeks 3–12) and the first fear period (weeks 8–10). Most modern puppy development frameworks, including ours, trace back to this work.
Freedman, King & Elliot, Critical Period in the Social Development of Dogs (1961, Science) — established that puppies socialised with humans between weeks 3–12 form measurably stronger bonds, and that the window closing around week 12–14 has lasting effects.
Organisational guidance
American Veterinary Society of Animal Behavior (AVSAB) — our socialisation timing follows AVSAB's position statement, which holds that the behavioural risk of under-socialising a puppy is greater than the disease risk of socialising before their vaccine series is finished.
American Kennel Club (AKC) — developmental stage and growth timelines are cross-referenced against AKC's published guidance, including breed-size-specific differences.
Applied guidance
Beyond the academic and organisational sources above, our training and behaviour framing draws on established applied-behaviourist and professional-trainer literature — covering session structure, fear-period pacing, and early intervention for common behaviour concerns.
On breed size
Small and toy breeds physically mature faster (growth plates close earlier) but reach behavioural and social maturity later than their size suggests. Fear-period timing itself is broadly consistent across sizes; it's adolescence onset that tends to begin notably earlier in small breeds. Our small/toy track reflects that documented difference.
On feeding and energy needs
Our puppy feeding calculator estimates daily calories as resting energy requirement (70 × bodyweight in kg0.75) multiplied by a life-stage growth factor. The growth factors come from the National Research Council, Nutrient Requirements of Dogs and Cats (2006), as summarised for practitioners by the Merck Veterinary Manual and the FEDIAF Nutritional Guidelines (the European industry standard). We present the result as a range, not a single number, because these equations are population averages and can over- or under-estimate an individual puppy — body condition and a vet’s input are the real check.
On dog aging
Wang et al., Quantitative Translation of Dog-to-Human Aging by Conserved Epigenetic Clocks (2020, Cell Systems) — our dog age in human years tool uses this study's formula, human age = 16 × ln(dog age) + 31, derived from DNA-methylation clocks shared between dogs and humans. It replaces the unscientific "multiply by 7" rule. The study was derived from Labrador Retrievers, so we present the result as a well-grounded approximation, not an exact figure.
What this isn't
Puppyweeks, including Copilot, is educational — not veterinary advice, training certification, or a clinical assessment. Anything touching health, injury, aggression, or a sudden behaviour change should go to a vet or a certified trainer (CPDT-KA or CAAB). See the Terms of Service for the full disclaimer.
Questions
Email hello@puppyweeks.app.