A dog is a teenager from around 6 months of age until roughly 18 months, when most dogs begin to settle down mentally. The period is comparable to puberty in humans: the body is well advanced in its physical development, while the brain is still working on finishing up. Exactly when your dog enters and exits the teenage phase depends especially on breed and size. Small dogs mature faster and can be mentally adult already around one year of age, while the large breeds often only put the worst of their youth behind them as they approach two years.

It is a phase that many new dog owners are surprised by. The little puppy that followed faithfully and learned quickly suddenly transforms into an independent young dog that tests boundaries, pretends to have gone deaf on the walk and reacts differently to the world around it. This is completely normal, and it passes. Below you get an overview of when the different stages occur, what happens inside the dog, and how you can best support it through them.

When does the teenage phase start and end in dogs?

The teenage phase typically begins when puppyhood ebbs away around 5-6 months of age. This is when sexual maturity sets in, and the hormones truly begin to affect both body and behaviour. In male dogs it is often seen when they begin to lift their leg and take more interest in scents and other dogs. In females, the first heat marks the entry into the phase, and for most it comes somewhere between 6 and 12 months.

The end of the phase is more gradual and hard to pin to a precise date. For a small dog the mind may already have settled around 12 months, while a medium-sized dog is often through the worst of it at 15-18 months. The very large breeds, such as the Great Dane or Bernese Mountain Dog, on the other hand may still behave like youngsters when they are one and a half to two years old, precisely because their overall development takes longer. A good rule of thumb is that the larger the dog becomes as an adult, the longer the youth lasts.

How behaviour changes when the dog becomes a teenager

The most striking change is that the dog suddenly seems more independent and at times downright forgetful. Commands that were perfectly in place during puppyhood can for a period appear to have vanished entirely. This is not due to disobedience or defiance, but to the brain undergoing a major rebuilding, where the connections between impulses and self-control are not yet in place. Your young dog wants to, but it struggles to keep a cool head when the world is full of exciting scents, sounds and fellow dogs.

Many also find that the dog becomes more sceptical of things it previously took calmly. A rubbish bin, a flagpole or a person with an umbrella can trigger sudden insecurity. This is called a fear period, and typically one or two of them occur during youth. At the same time, the urge to play and the energy can be at their peak, and a dog with a high activity level can find it hard to wind down on its own. Some young dogs also begin to test their place in the interaction with other dogs and can seem more assertive in encounters with fellow dogs than they were as puppies.

How to support your young dog through puberty

The best thing you can do is to keep doing what you did during puppyhood, just with even more patience. Maintain the training in short, positive sessions, and do not expect everything to work perfectly from day to day. Reward the behaviour you want to see more of, and avoid scolding when the dog seems forgetful — it only creates confusion and insecurity. Consistency and predictability give your young dog something to lean on while the rest of it falls into place.

Make sure the dog gets an outlet for both body and mind. Scent work, search exercises and simple enrichment tasks often tire out a young dog more than long runs, and at the same time help it learn to concentrate. A THE LICKING MAT is a simple way to provide calm and focus in everyday life, for example spread with a little PÂTÉ when the dog needs to settle down after a walk. If the dog encounters something it becomes afraid of during a fear period, never push it towards the object, but let it set the pace itself and calmly affirm it when it handles the situation.

Meals that match a young dog in growth

Even though the teenage dog looks like an adult version of itself, it is physically still under construction. Bones, muscles and joints are in full development, and this places demands on the daily meals. A young dog needs a well-considered nutritional profile that supports growth without pushing it. When you switch from puppy meals to adult meals depends once again on size, and you can find a complete overview in our universe for puppy & junior, where the advice comes directly from ESSENTIAL FOODS.

At ESSENTIAL FOODS all meals are prepared from human-grade ingredients and fresh produce, composed with carefully selected local and regional delicacies. The BEGINNING series is created for the finest beginning with luxurious, grain-free puppy meals that are entirely without grain and unnecessary fillers, and it suits the young dog until it is ready to move on. If you are in doubt about when and how to adjust the meals to your particular dog's breed, size and life stage, ESSENTIAL FOODS' nutrition advisers are ready to help you further by phone, chat or email.

When is the dog considered adult again?

The transition from teenager to adult happens gradually. Physically, most small dogs are fully grown around 10-12 months, while large breeds only finish building their body at one and a half to two years. Mentally, maturity often follows a little behind the physical, and therefore a dog may well look adult long before it behaves like one. When the dog begins to listen more reliably, handles new situations with greater calm and once again appears as a dependable companion, it is on its way out of youth.

If you want to delve deeper into when your dog can genuinely be considered fully grown across both body and mind, you can read more in our guide when is a dog adult. The teenage phase can feel long while you are in it, but it is a completely natural part of having a dog. With patience, good routines and meals that match the dog's needs along the way, you get through it together, and on the other side awaits a well-balanced adult dog that benefits from everything you built up along the way.