The teenage dog: why your well-trained puppy suddenly forgot everything

You did everything right. You went to puppy school. You practised recalls, you worked on loose leash walking, your pup sat on cue like an absolute champion. Then somewhere around six or eight months old, something changed. Suddenly your dog is selective about when they bother listening, pulling on the lead, ignoring their name, and generally behaving like a stranger who has never met you before.

Welcome to adolescence. It is one of the most challenging — and most commonly misunderstood — phases of dog ownership. And it is absolutely, one hundred per cent, survivable.

When does adolescence happen?

Dog adolescence typically begins somewhere between six and eight months of age, though this varies significantly depending on breed and size. Small breeds often hit adolescence earlier and move through it faster. Large and giant breeds can start later and take considerably longer — some larger dogs aren’t fully neurologically mature until two or even three years of age.

As a general guide:

Small breeds: roughly 6–12 months
Medium breeds: roughly 6–18 months
Large and giant breeds: can extend to 18–24+ months

If your dog is somewhere in this window and driving you up the wall, there’s very likely a neurological explanation for it.

What’s actually happening in your dog’s brain

Adolescence isn’t just about hormones, though hormones are certainly part of the picture. What’s happening is something far more fundamental: your dog’s brain is undergoing a massive rewiring process.

The prefrontal cortex — the part of the brain responsible for impulse control, decision-making, and the ability to think before acting — is still under construction. This is the same thing that makes human teenagers do spectacularly impulsive things, and it’s what makes your teenage dog bolt after a pigeon the moment their lead comes off, despite a perfectly reliable recall last month.

On top of the brain rewiring, hormones are surging. For intact dogs, this is amplified — the hormonal changes of puberty have a strong effect on behaviour and can make training feel significantly harder. This is one reason many vets recommend desexing, though the timing should always be discussed with your vet based on your individual dog’s breed and health.

Adolescent dogs also tend to become much more aware of and interested in the world around them. Things that seemed irrelevant before — smells, other dogs, sounds, movement — suddenly become intensely fascinating. The environment becomes genuinely more compelling than you are. This isn’t disrespect or stubbornness. It’s biology.

Why previously learned behaviours seem to disappear

Here’s something that surprises a lot of owners: your dog hasn’t actually forgotten what they learned. The information is still in there. What’s changed is their ability to access and perform that behaviour reliably, particularly when they’re aroused or distracted.

Think of it like this: your puppy learned to sit in the kitchen, in a calm state, with your full attention. Your adolescent dog is being asked to sit while a cat runs past, a teenager on a skateboard goes by, and three dogs are playing 20 metres away. The behaviour hasn’t been “unlearned” — it just hasn’t been taught to the level of reliability needed for that environment.

I often tell owners at this stage: your dog isn’t broken, and you haven’t failed. You’ve just hit a developmental stage that requires you to adapt your approach.

Why you absolutely cannot give up on training now

This is the most important message in this entire post: please do not stop training your dog during adolescence. I know it’s tempting. The sessions that used to go so well now feel like an uphill battle. Your dog seems checked out. It can feel like you’re wasting your time.

But adolescence is precisely when consistent, positive training matters most. The habits and associations your dog develops during this period shape who they become as an adult. An adolescent dog who learns that checking in with you is rewarding, that good behaviour pays off, and that training is a fun game — that dog becomes a genuinely enjoyable adult companion. An adolescent dog who is essentially left to their own devices during this period can develop habits that are much harder to shift later on.

Keep showing up. Shorter sessions, lower criteria when needed, massive rewards for small wins. The work you put in now has a disproportionately large impact.

What works best for adolescent dogs

Standard training advice doesn’t always translate well to the teenage phase. Here’s what I find most effective:

Keep sessions short and punchy. Five minutes of genuinely engaged training beats 20 minutes of a distracted dog. End before they disengage.
Increase your reward value. If chicken worked as a puppy, you may need to upgrade to steak. High arousal environments require high value reinforcement.
Drop your criteria temporarily. If your dog had a rock-solid stay in the kitchen, rebuild it in a slightly more distracting environment before expecting it near the dog park. You’re not going backwards — you’re proofing.
Prioritise engagement exercises. Games that teach your dog to voluntarily check in with you, to find you more interesting than the environment, are gold at this stage. Eye contact games, recall games, and general play that centres around you all help rebuild that connection.
Give them appropriate outlets. An adolescent dog has a lot of energy and a lot of brain power. Sniffing walks, enrichment games, chewing, and appropriate play with other dogs are all important outlets that make training easier.
Stay consistent. The rules that applied when they were a puppy still apply now. Inconsistency is particularly confusing for adolescent dogs and makes behaviour wobble more.

Group classes: especially valuable at this stage

Training in a group environment during adolescence is genuinely valuable — not despite the distractions, but because of them. Learning to focus around other dogs, to respond to cues in a stimulating environment, is exactly the proofing work adolescent dogs need. Our Teen Dog Classes are designed specifically for this exact stage — structured to meet adolescent dogs where they are and build the skills that matter most during this phase.

This phase does end

I promise you: it ends. The dog who is currently bouncing off the walls and ignoring everything you say will, with consistent training and a bit of time, settle into an adult dog. Most owners notice a significant shift somewhere between 18 months and two years — and when it happens, it feels like suddenly having the dog you always knew was in there.

The teenage phase is hard, but it’s also a genuinely important time in your dog’s development. Your patience and consistency right now are shaping who your dog will be for the next decade or more. That is worth holding onto on the difficult days.

If you’re in the thick of the teenage phase and feeling overwhelmed, you’re not alone — and you don’t have to figure it out by yourself. Come and join us in class, or get in touch to chat about the best way forward for your dog.

The teenage dog: why your well-trained puppy suddenly forgot everything