Why These First Weeks Matter
Your puppy's early experiences quite literally shape their brain. During the first 16 weeks of life, rapid neural development means every interaction—or lack of one—influences how your puppy learns to respond to the world. Research shows that puppies raised with appropriate early exposure develop stronger coping skills, better social resilience, and fewer behaviour problems throughout their lives.
The Science of Early Development
Modern Evidence on Early Care
Current evidence (based on behavioural studies) supports weaning between 8-12 weeks, not earlier. Puppies who remain with their littermates longer develop better bite inhibition, social skills, and emotional resilience. However, puppies can leave their mother as early as 8 weeks if the new home provides appropriate socialisation opportunities.
Why it matters: Early separation without proper social scaffolding correlates with increased anxiety and aggression issues later in life.
The "socialisation vs. vaccination" debate is now resolved by evidence. Puppies should NOT be isolated until fully vaccinated. The risk of missing the critical socialisation window (6-16 weeks) outweighs the relatively low disease risk for puppies from vaccinated parents in low-risk environments.
Safe strategies include:
Why it matters: Puppies missing this window often develop lifelong anxiety, fear-aggression, and reactivity that is extremely difficult to resolve.
While puppies benefit from safe floor exposure, avoiding contaminated public areas is sensible disease prevention. Carrying puppies (or using strollers) to see busy environments is an excellent compromise—they get exposure without high contamination risk.
Strategic off-floor exposure includes:
How to Use This Guide
This guide is divided into practical sections. Start with the Development Timeline to understand what's happening in your puppy's brain week by week. Use the Development Planner to track what exposures and skills to focus on each week. Refer to Troubleshooting when challenges arise, and use Training Goals to build essential skills. Science Facts will help you understand the 'why' behind every recommendation. Use the Handling & Confidence section to track your progress with practical checklists.
Click on each stage to expand and learn what's happening in your puppy's brain and what to focus on during that period.
The puppy's nervous system is still developing. Their eyes and ears don't yet work properly—they navigate primarily through smell and touch.
What They're Learning:Mother recognition, littermates, basic temperature regulation, hunger/satiation cycles.
Emotional Development:No fear response yet—puppies are dependent and responsive mainly to warmth and comfort.
What Owners Should Do (if hand-rearing):Eyes open (though vision is still poor). Ears begin opening. Brain development accelerates. Neurological reflexes are becoming established.
What They're Learning:Visual recognition, basic social skills with littermates, beginning to eat solid food.
Emotional Development:Beginning to recognise caregivers. Starting to respond to voices and sounds.
What Owners Should Do:Rapid synaptic development. The brain is developing at its fastest rate. Fear conditioning begins—puppies can now learn to be afraid of things.
What They're Learning:Bite inhibition from littermates, appropriate play styles, basic body language, responses to human leaders.
Emotional Development:Puppies are naturally curious and exploratory. They begin forming preferences and aversions based on experience. This is the CRITICAL window for building confidence and positive associations.
What Owners Should Do:The peak of the socialisation window. Synaptic density is at its highest. Experiences during this time have lasting effects. Fear responses are more pronounced now—the "fear period" often begins around week 8-9.
What They're Learning:Social interactions and appropriate play. Responses to novelty. What is "safe" and "dangerous" based on their experiences. Early learning about humans and other dogs.
First Fear Period (Weeks 8-10):Many puppies experience a temporary increase in wariness and fear responses. This is normal. Do not ignore fear—instead, advocate for their need to feel safe You can not reinforce an emotional state of fear, it isn't possible!.
What Owners Should Do:Continued refinement. Baby teeth are lost and adult teeth erupt. Increased physical coordination. Prefrontal cortex (executive function) still developing—impulse control is limited.
What They're Learning:Social boundaries, bite inhibition refinement, learned behaviours becoming habits, testing boundaries.
Second Fear Period (Weeks 16-20):Another temporary increase in fear,wariness is common. Again, maintain positive exposure.
Teething & Chewing:Intense during this period (weeks 16-28 particularly). This is not misbehaviour—it's a developmental phase. Provide appropriate outlets.
What Owners Should Do:Hormonal surge (if not neutered,spayed). Executive function still immature. Puppy becomes stronger, faster, and more confident—but judgment hasn't caught up. The teenage brain!
What They're Learning:Testing boundaries aggressively. Independence increases. Same-sex aggression can emerge. Hormonal behaviours (marking, roaming drive) appear.
Behavioural Changes:Puppies often regress—skills they knew suddenly "disappear." This is normal. The adolescent brain is reorganising. Consistency is critical.
What Owners Should Do:Prefrontal cortex reaches full maturity around 2-4 years (varies by breed, larger breeds mature later). The adolescent phase wanes. Personality fully emerges.
What They're Learning:Refined social skills, established habits (good or bad), consistent responses to their world.
What Owners Should Do:Click on each month,phase to expand and see what to focus on. Track your puppy's development progress.
Focus Areas
If puppy is with mother: Minimal intervention needed. Mother is doing the job. Gentle handling by consistent people only.
If hand-rearing: Appropriate nutrition, temperature control, toileting assistance.
Exposure Targets
Training Focus
Management
Exposure Targets
Training Focus
Veterinary & Care
Management
Exposure Targets
Training Focus
Management
Exposure Targets
Training Focus
Management
Training Focus
Management
Training Focus
Management
Consolidation
Click on each skill to expand and learn how to teach it. Each skill serves a purpose in building a cooperative, confident puppy.
Sitting is incompatible with jumping, pulling, mouthing, and other unwanted behaviours. Teaching sit teaches your puppy that sitting gets good things. This becomes their default choice.
How to teach it:Puppies can learn basic sit response by 8 weeks. Reliable sit takes until 12-16 weeks with daily practice.
What NOT to do:Once sit is reliable, use it as foundation for stay, for greeting people, at doorways, etc.
Teaching a puppy where to be calm is more effective than punishing them for being aroused. A settle behaviour gives you control over arousal levels and teaches impulse control. It's also essential for vet visits, grooming, and home management.
How to teach it:Puppies can learn to go to mat by 10 weeks. Reliable settle for 5+ minutes takes 8-12 weeks of daily practice.
What NOT to do:Use mat work for: quiet time during your work, during meals, when guests arrive, calming before excitement (car rides, walks), grooming practice, vet visits.
A puppy who will look at you when asked can be redirected away from danger, is easier to manage in social situations, and learns faster because they're attending to you. Focus is literally "training readiness."
How to teach it:Puppies can learn basic focus response by 8 weeks. Reliable focus with distractions takes 10-16 weeks of consistent practice.
What NOT to do:Use focus to redirect attention, before introducing new experiences, during training sessions, in social situations, to interrupt unwanted behaviours gently.
Reliable recall keeps your puppy safe, allows you to give them freedom, and is essential for emergency situations. A puppy who comes when called has a much better quality of life.
How to teach it:Puppies can learn basic recall by 10 weeks indoors. Outdoor recall reliability takes months of consistent practice. It's an ongoing skill, not a one-time achievement.
Critical rule:NEVER punish or scold when puppy finally comes, no matter how long they took or what they were doing. Coming to you must always be rewarding.
What NOT to do:Off-lead play, emergency situations, outdoor adventures. Build this skill gradually and maintain it throughout life.
Walking is where puppies spend significant time. Teaching loose lead walking makes walks enjoyable for both of you, prevents injury, and teaches impulse control. It's fundamental to owning a dog.
How to teach it:Puppies can learn loose lead basics by 12 weeks. Reliable loose lead in all situations takes months of consistent practice.
What NOT to do:Daily walks, community interactions, grooming appointments, vet visits, controlled socialisation experiences.
Click on each challenge to expand and understand what's happening and how to respond effectively.
Chewing is a normal puppy behaviour. It serves several purposes: exploration, teething relief (especially weeks 16-28), boredom,frustration release, and anxiety self-soothing. Puppies explore the world with their mouths.
Puppies don't regress for spite. Common causes: developing bladder control (normal development), dietary changes, parasites, stress,anxiety, changes in routine, hormonal changes (adolescence), marking behaviours (territorial,sexual).
Puppies jump because they've been rewarded for it (attention, interaction, reaching face level) or because they lack impulse control. From the puppy's perspective, jumping gets results.
Puppies become over-aroused when they lack adequate physical,mental exercise, have inconsistent boundaries, are repeatedly over-stimulated, or lack appropriate settling time. A tired puppy is a well-behaved puppy—but not all energy is physical.
Puppy fear is sometimes developmental (fear periods at 8-10 weeks and 16-20 weeks), sometimes learned (negative experience), sometimes genetic predisposition. Fear left unaddressed becomes phobia.
Enrichment isn't just fun—it's essential for brain development. Mental stimulation actually changes the puppy's brain architecture, building stronger neural connections and increasing cognitive reserve.
Why Enrichment Matters Neurologically
Age-Appropriate Enrichment Ideas
Sensory Exploration
Sniffing: Hide treats in towels, boxes, or grass for puppies to find
Texture exploration: Different surfaces: carpet, tiles, wood, grass, gravel
Novel objects: Umbrellas, cones, garden tools (introduce calmly)
Sound exposure: Household sounds at normal volumes
Puzzle & Problem-Solving
Snuffle mats: Hide kibble in woven mat for foraging
Puzzle toys: Kong wobbler, puzzle feeders
DIY puzzles: Hide treats in ice cube trays, toilet paper tubes
Treasure hunts: Hide treats around house or garden
Training as Enrichment
Learning new skills: Tricks, games, complex commands
Scent work: Finding hidden treats or objects
Obstacle courses: Gentle agility for confidence building
Games with rules: Hide and seek, find it games
Calm Enrichment
Chewing: Long-lasting chews, bully sticks, raw bones (supervised)
Lick mats: Spread yogurt, peanut butter on textured mat, freeze
Sniffing outdoors: Long, leisurely sniff walks
Settle time: Quiet observation time in different environments
Teaching your puppy to be comfortable with handling is foundational. Track your progress with these checklists—they save locally so you can return to them.
Consent Petting: Respecting Your Puppy's Boundaries
Your Puppy Has a Right to Say No
Consent-based petting means respecting your puppy's signals about touch. Not every puppy wants to be petted all the time, and forcing interaction can create negative associations with handling. Learning to read and respect your puppy's boundaries builds trust and prevents stress-related behavioural issues.
Protecting Your Puppy From Over-Handling
Too Much Touch is Stressful
Puppies are irresistibly cute, but constant handling can actually create stress and anxiety. Puppies need downtime to process and rest. Over-handled puppies sometimes develop hand-shy or touch-sensitive behaviour as adults.
Create No-Touch Zones
When your puppy is on their mat or in their bed, that's a space where they're not available for petting. This teaches that they have safe places where they can rest without being touched. Respect these boundaries.
Limit Visitor Interactions
You don't have to let everyone pet your puppy. It's perfectly fine to say "He needs a break" or "She's resting right now." Your puppy's wellbeing comes before others' desire to pet them. Quality interactions with people who respect boundaries are better than constant interactions with people who don't.
Teach an Off-Switch
Teach visitors that petting stops when your puppy walks away or shows discomfort. No picking up or pursuing. If they leave, let them leave. This teaches your puppy that they have control and can ask for space.
Development Milestones Checklist
Week 4-8 Milestones
Week 8-16 Milestones
Month 4-6 Milestones
Development Stages Checklist
Neonatal to Early Socialisation (Weeks 0-8)
Critical Socialisation Window (Weeks 9-16)
Juvenile Period (Weeks 16-32)
Adolescence (Months 8-18)
Early Adulthood (18+ Months)
Early Care Sets the Stage
Your puppy's experiences with veterinarians and groomers now determine how they'll cooperate with care throughout their life. A puppy who learns that vet visits are safe and predictable becomes an adult who doesn't need restraint or sedation for routine care.
Veterinary Care: Building Positive Associations
Nutrition: Feeding Your Growing Puppy
Nutrition Changes as Your Puppy Grows
Your puppy's nutritional needs change dramatically as they grow. The balance of protein, fat, calcium, and phosphorus that works for an 8-week-old puppy is completely different from what a 6-month-old needs. Feeding appropriately for your puppy's age, size, and growth rate is crucial for healthy development and prevents joint problems, growth issues, and other health challenges.
Weeks 4-8: Multiple Small Meals
Young puppies need 3-4 meals daily of high-quality puppy formula. Their stomachs are tiny. Quality matters more than quantity—premium puppy food with appropriate calcium and phosphorus levels supports proper bone development.
Months 3-6: Growth Acceleration
Your puppy may triple in size during this period. Nutritional demands are high but must be carefully balanced. Too much calcium can damage growth plates, particularly in large breed puppies. Working with a nutritionist during this critical phase prevents lifelong joint issues.
Months 6-12: Continuing Growth
Most puppies can transition to twice daily feeding. Portions and nutrient ratios adjust as your puppy approaches adult size. Large and giant breed puppies remain in growth stages longer and have specific requirements to protect developing joints.
12+ Months: Approaching Adult Feeding
Growth plates begin closing around 12-18 months (later for large breeds). Transition to adult food gradually when growth plates close completely (discuss timing with your vet). Adult nutrition differs significantly from growth nutrition.
Exercise: Building Healthy Bodies Through Rest
Puppies Need REST More Than Activity
This might surprise you, but puppies need extensive sleep and rest for healthy development. Their bones are still forming, their joints are vulnerable, and their nervous systems are developing. Excessive exercise doesn't create a healthier dog—rest does. In fact, over-exercising puppies can cause lasting damage to growth plates and joints.
Weeks 4-8: Minimal Structured Exercise
Puppies should play freely indoors and in the garden, but structured walks aren't necessary yet. Let them move naturally and rest frequently. Avoid repetitive jumping, stairs, or high-impact activities. Free play is fine, forced exercise is not.
Months 3-6: Gentle Introduction to Walking
Short, frequent walks are appropriate. A general guideline is 5 minutes per month of age, twice daily (so a 4-month-old gets 20-minute walks). But these are guidelines, not rules. If your puppy is tired, stop. Avoid long walks, jumping from heights, or intense play. Hard surfaces can be tough on developing joints.
Months 6-12: Gradual Increase
Exercise can gradually increase, but still prioritise rest. Avoid high-impact activities (jumping, repetitive running) until growth plates close. Swimming is excellent low-impact exercise. Mental enrichment (training, sniffing) is equally important and less taxing than physical exercise. Your adolescent puppy shouldn't be doing long hikes or running beside bicycles yet.
12+ Months: Approaching Adult Exercise
Growth plates close gradually between 12-18 months (larger breeds later). More intense exercise becomes appropriate only as growth plates fully close. Discuss appropriate exercise timing with your vet based on your puppy's breed and individual development.
Grooming & Professional Care
If your puppy will need regular grooming, starting early and building positive associations is critical. Visit groomer 2-3 times for socialisation before any grooming occurs. During early visits, just let your puppy meet the groomer and explore the salon.
Preventative Healthcare
Understanding the science behind puppy development helps you appreciate why your approaches matter. Here are fascinating insights from behavioural science and neuroscience.
🧠 Brain Development is Explosive in Early Weeks
A puppy's brain increases in weight from about 3 grams at birth to 99% of adult size by 8 weeks. The structure of this developing brain during weeks 4-16 is literally being shaped by experiences. Novel experiences create new neural connections, lacking experience creates fewer connections. This is why early exposure matters so much.
🧠 The "Critical Period" for Socialisation
Between weeks 3-12, puppies experience a unique window of reduced fear responses and high curiosity. During this period, puppies naturally approach novelty with confidence. After week 12, fear responses increase significantly. This is why experiences during this window are so valuable—the puppy's brain is primed to integrate novelty as "safe."
😱 Fear Periods Are Real and Predictable
Puppies typically experience a first fear period around weeks 8-10 and a second around weeks 16-20. During these periods, normally confident puppies may suddenly become cautious or fearful. This is a normal developmental phenomenon related to brain development. It passes—don't coddle or avoid exposure, just maintain normal, gentle exposure and reassure them they're safe.
🧬 The Adolescent Brain Reorganisation
During adolescence (roughly 6-18 months depending on breed), the brain undergoes significant reorganisation. The prefrontal cortex (responsible for impulse control and judgment) is restructuring. This is why adolescent puppies seem to "forget" what they knew and have poor impulse control. It's not defiance—it's neurobiology. Consistency through this phase is critical.
🎯 Bite Inhibition is Learned, Not Instinctive
Puppies aren't born knowing not to bite. They learn bite inhibition from littermates (who yelp and stop playing when bitten), and from human feedback. Puppies who don't learn appropriate bite inhibition by 4-5 months often develop problems managing their bite force in adulthood. This is why mouthing,nipping phases are important to manage correctly.
🐾 Littermate Separation is Important But Not at Any Cost
Puppies separated from littermates too early (before 8 weeks) miss crucial learning about social communication, bite inhibition, and play styles. However, being with littermates beyond 12 weeks can actually create problems (littermate bonding that excludes humans, sibling conflict). 8-12 weeks is the optimal window for littermate separation.
🎓 Training Creates Physical Brain Changes
Learning new skills literally builds brain structure. Learning to sit, learning focus, learning tricks—all create new neural pathways and increase neural density. A puppy who learns multiple behaviors has a physically different (larger, more connected) brain than an unstimulated puppy. Training isn't just teaching behavior, it's literally building brains.
🧠 Stress Hormones Can Alter Brain Development
Repeated stress during the critical developmental period (cortisol release) can actually alter brain structure, particularly in areas responsible for emotional regulation and fear response. Puppies raised in stressful environments (isolation, punishment, overstimulation) show altered fear responses and anxiety in adulthood. Creating a safe, positive early environment literally changes brain chemistry.
⚖️ Positive Reinforcement Creates Faster Learning Than Punishment
Neurologically, reward-based training activates the brain's dopamine reward system, which promotes learning and memory formation. Punishment activates fear and stress responses, which can actually inhibit learning. A puppy trained with rewards learns faster and remembers better than one trained with punishment. It's not just kinder—it's more effective.
💡 Enrichment Actually Changes Brain Size
Puppies raised with cognitive enrichment (puzzles, varied environments, learning opportunities) actually develop larger hippocampi (crucial for learning and memory) than unstimulated puppies. Environmental enrichment isn't just fun—it creates measurably different brains with better capacity for learning, memory, and stress resilience.