Your puppy will go through several periods of change from birth to adulthood, we call these puppy development stages. Knowing when these are, and what happens in different stages of development, will help you understand why your puppy might be behaving in a certain way or struggling with certain things.
In this article we’ll help you understand the 7 stages of puppy development, what physical and mental changes your puppy will go through during these periods, so you know what to expect. We’ll also discuss how important positive reinforcement training will be throughout this time to build a strong bond with your puppy.
Download the Zigzag puppy training app to get a puppy training programme that takes you through every stage of your puppy’s development week by week. We have a team of experienced dog trainers to support you and answer all of your puppy-related questions, to help you every step of the way.
Different sources will give anything between 4 and 7 developmental stages, from when a puppy is firstborn to when they are a mature dog, and there is also overlap and certain periods happening at the same time!. We’re a science based app, so we’re going to give you the in depth guide, to help you fully understand it.
There are also puppy fear periods which add another element to puppy development stages, you can learn even more about them in our article on puppy fear periods.
1. The Neonatal Stage (0 to 2 Weeks)
This first stage of puppy development is when a puppy is newly born. At this age, they are totally blind and cannot hear or move around much, and they’re also unable to regulate their temperature well. You’ll typically see them in a puppy pile to stay warm, and they will also stay close to their Mum as they will want access to food all the time.
Towards the end of the neonatal stage, a puppy’s eyes will begin to open (roughly between days 10 and 14) allowing them to start to see objects that are close by.
2. The Transitional Stage (2 to 3 Weeks)
During the transitional stage, a puppy starts to become more sensitive to sound, and they can see objects a few inches away.
They start to move around more, and acquire motor skills which means they can walk and waddle, though it looks pretty clumsy, and they often fall over!
Puppies become much more explorative at this age, and sniff, lick and nibble on things in their environment. Because they’re getting better at regulating their temperature, you’ll often see them leave the whelping box for a nose around too.
3. The Primary Socialisation Stage (3 to 5 Weeks)
This stage of puppy development features some big changes as puppies really spring into action and start learning about their world. They move around more, play with their littermates, vocalise with barks and growls, and wag their tails. They also begin to learn social cues and bite inhibition from their mother and littermates.
During this time, puppies need exposure to normal household noises such as vacuum cleaners and washing machines to learn they are not scary. They should also be handled extensively in a positive way, and meet and interact with plenty of different people.
At 3 weeks, they can slowly start to have solid foods introduced as their mother starts to wean them off her milk. They will have their puppy teeth coming in and feeding starts to hurt their mother, so it becomes quite natural for her to withdraw a little and for them to eat other foods.
Learn more about puppy socialisation in our full guide to puppy socialisation.
4. The Secondary Socialisation Stage (5 to 12 Weeks)
The secondary socialisation stage as the name suggests sees puppies learn about the world through the process of socialisation and habituation so that they understand that different surfaces, people, and sounds are part of everyday life and don’t need to be scary.
Between the ages of 5 and 12 weeks, your puppy will go through a rapid stage of mental development as well as many physical changes, such as cutting all their puppy teeth. They will be biting and mouthing a lot during this period, usually in play with their littermates, who will squeal when bitten too forcefully, so your puppy can learn bite inhibition.
At 8 weeks puppies are weaned and move onto puppy food entirely, and they also learn where they should go to the toilet. This can be taught by their mother if access to outside is safe, but a puppy toilet should also be provided by their breeder.
Puppies also go into their first fear period, and can suddenly seem frightened of things they were fine about previously. It’s important not to overwhelm them at this age, and it can be a fine balance between positive exposure to things while keeping them under their stress threshold.
Learn more about what else happens in this developmental stage in our articles on puppy teething, puppy fear periods and puppy sleep explained.
We also go into detail in the Zigzag app, and teach you all about puppy development from birth including socialisation and habituation as well as what happens after you bring your puppy home with you.
5. The Juvenile Stage (12 Weeks to 6 Months)
Puppies will often be in their new homes either by or at 12 weeks of age.. During this developmental period they will be teething extensively, losing their baby teeth and will have adult teeth by the age of 5 months. It can often feel like they’re biting and mouthing at everything in sight, so it’s worth investing in plenty of Kongs, puppy chews and other brain games for them to go to town on.
They’ll need to be toilet trained in their new home, given appropriate exercise and start going outside for walks when fully vaccinated. While we think of the socialisation window being up to 12 weeks, in actual fact, puppies continue to learn about the world way after this time.
Enrolling in a puppy class is a good idea, as well as starting a positive reinforcement based training programme, like we have for you in the Zigzag app.
6. The Flight Instinct Period (4 to 9 Months)
During the flight instinct period, your puppy will become more confident and less likely to be glued to your side like they previously were. It generally starts when your puppy is ready to leave their den and explore the world on their own.
This is commonly when we have problems with things like recall, as puppies are less likely to need us! Train your puppy to come when called and let them off lead when they’re small, so you get plenty of practice before they’re in this stage!
7. The Adolescent Stage (6 Months to 24 Months)
From around 6 months old puppies enter adolescence, often called the terrible teens! This period of development can be up to 2 years in large breeds, though smaller breeds will mature faster.
Adolescence can be a difficult period as puppies begin to experience a wide range of emotions and their behaviour can feel quite challenging, with owners reporting that it feels like puppies are testing boundaries. It’s important to keep up the good work with training, and not think they’re already trained, they still require plenty of rewards to stay on the right track.
Puppies begin to sexually mature at this age, female dogs will begin to have seasons, and male dogs will begin marking their territory and may become interested in receptive females. We typically need to think about when is the right time to neuter or spay. From a behaviour perspective we like to wait until they are fully mature, though understandably rescue pups may need to be neutered younger.
Learn more in our article why is my puppy humping or read our full guide to neuter and spaying.
If you already have an adolescent puppy, we now have a specialist terrible teens programme in our app, and our team are ready to support you every step of the way!
The Fear Periods
Puppies go through distinct fear periods from when they are with their littermates to when they are mature. The behaviour seen will vary between the individual dog, but is typically categorised by them being wary and not wanting to interact with new things. They can also suddenly become scared of familiar things, or with heightened sensitivity to things they were fine with before. Your puppy might also appear clingy during these stages.
| Stage | Age of puppy |
| Hazard Avoidance/Initial Fear Stage | 7-11 weeks |
| Adolescent fear stage | 12 weeks – 6 months |
| Flight instinct period | 4-9 months (can be up to 14 months depending on the breed) |
| Adult fear period | 12-18 months |
8. Adulthood
The age at which your puppy reaches adulthood will vary depending on their breed or size, with small and toy breeds developing both physically and mentally faster than giant breeds like Newfoundlands or Great Danes.
Although they may be adult dogs they still have a lot to learn, and it’s important that we carry on teaching them; be that basic obedience and manners training, tricks, agility or scentwork. Dogs are always learning, and they enjoy it too, so keep on training them and help to flex those grey cells.
Neutering is probably what you want to consider now, with the cost varying depending on the size of your dog and where you are in the world. Neutering helps to prevent accidental pregnancies and generally makes life easier for you, especially if you live in a city or are surrounded by lots and lots of dogs. It’s totally a personal decision, though, so worth discussing with your vet.
How can Zigzag help with your pup’s training
The Zigzag app helps train puppies in a structured and logical way, where each stage of the programme is designed to coincide with your puppies age and stage of development, so you get the right lessons when you need them most.
If you have any questions at any point, you can also get in touch with our team of professional puppy trainers to help guide you and give you the right answers. They’re available 24/7 in our app.
FAQs
- What age are puppies most hyper?
Puppies are most hyper when they are tired! When puppies are overtired they frequently get zoomies and run around like crazy. They also get zoomies post bath, or after other periods of stress.,
- What age do puppies get their personality?
Puppies start to get their personality from as little as 4 weeks of age. Breeders are often good at matching new puppies with their new home, because, by the time the puppy is due to leave, they have picked up on each puppy’s individual personality,
- What is the naughtiest puppy age?
Adolescence or teenage puppies tend to be thought of as the naughtiest as this is the stage where they are finding out how the world works, and what they can do and can’t do. Management to prevent running off and counter surfing as well as teaching skills like loose lead walking, leave it and recall will be useful at this age.
