Three months ago, your dog was the star of puppy school. Sat on cue. Came when called. Walked on a loose lead like a champion. Now? The recall has vanished. Sit takes four attempts. The lead goes tight the moment you leave the driveway. And you’re standing in the park, treat bag in hand, wondering what on earth happened.
What happened is adolescence. Your dog hasn’t forgotten the training — the dog’s brain is under renovation. Adolescent dog regression is one of the most common (and most misunderstood) phases of dog development, and it catches owners off guard because nobody warned them it was coming. The good news: it’s temporary, it’s normal, and the training you’ve done hasn’t been wasted.
Dog adolescence typically runs from six to eighteen months (longer for large breeds). During this phase, hormonal surges and brain remodelling cause temporary regression in trained behaviours, increased independence, reduced focus, and sometimes new fears. A 2020 study confirmed that dogs at eight months are significantly less responsive to their primary carer’s commands — but not to strangers’, mirroring human teenage behaviour. The fix: keep training, lower expectations temporarily, increase enrichment, use a long line for safety, and ride it out. Punishing the regression makes it worse.
What Is Adolescent Dog Regression?
Adolescent dog regression is the temporary decline in trained behaviours that occurs when a puppy enters the canine equivalent of the teenage years. Commands the dog responded to reliably at five months suddenly seem to evaporate at eight or nine months. Recall disappears. Lead manners deteriorate. House training may slip. The dog becomes more independent, more easily distracted, and less interested in doing what you ask.
This isn’t stubbornness, defiance, or a sign that the training failed. The dog’s brain is literally rewiring itself. The prefrontal cortex — the part responsible for impulse control, decision-making, and emotional regulation — is still developing, while the limbic system (emotions and instinct) is running in overdrive. The result is a dog that feels everything intensely but has less capacity to think before acting.
When Does It Start and How Long Does It Last?
Adolescence doesn’t arrive on a specific date, but the general windows are consistent across breeds.
- Small breeds (Chihuahuas, Toy Poodles, Jack Russells): typically starts around five to six months, wraps up around twelve to fourteen months.
- Medium breeds (Kelpies, Staffies, Border Collies): roughly six to eight months onset, settling by sixteen to eighteen months.
- Large and giant breeds (Labradors, German Shepherds, Great Danes): can start at eight to ten months and continue well past two years. Some livestock guardian breeds don’t fully mature behaviourally until three to four years.
The peak of the regression — the point where owners most commonly say “my dog has forgotten everything” — tends to hit around eight months. A landmark 2020 study published in Biology Letters by researchers at the Universities of Nottingham, Newcastle, and Edinburgh found that dogs at eight months showed significantly reduced obedience to their primary carer’s commands compared to the same dogs at five months and twelve months. The behaviour was temporary and carer-specific — the dogs still responded normally to strangers.
What Does Regression Actually Look Like?
Adolescent regression shows up differently in every dog, but certain patterns are almost universal.
Recall goes to pieces
The dog that used to sprint back to you now barely lifts the head when you call. Everything else — other dogs, smells, birds, a discarded chip packet — is more interesting than you. This is the most common and most frustrating regression owners report.
Lead manners unravel
A dog that walked nicely at five months is suddenly pulling, lunging towards distractions, or spinning on the lead. The world has become overwhelmingly stimulating, and the teenage brain hasn’t developed the impulse control to resist yet.
Commands need multiple repetitions
Sit. Sit. SIT. The dog knows the word. The dog has performed it a thousand times. But right now, the dog’s brain is processing a dozen competing inputs — a passing cyclist, a new smell, a rustling bush — and the command gets deprioritised.
New fears or reactivity appear
Some dogs go through a second fear period during adolescence, typically between six and fourteen months. A dog that was previously confident around traffic, strangers, or other dogs may suddenly become worried or reactive. A Kelpie that walked past garbage bins without blinking at four months might start barking at them at nine months. This isn’t a permanent personality change — it’s the brain re-evaluating what’s safe.
Increased independence and boundary-testing
The puppy that stayed glued to your side now wanders further, takes longer to check in, and seems far less interested in you as the centre of the universe. This is developmentally normal — adolescent animals across species move toward independence. But for a dog owner standing alone in a park while the dog ignores the recall, it doesn’t feel normal. It feels personal.
Chewing and destruction return
A secondary chewing phase hits around eight to ten months as adult teeth fully settle into the jaw. Shoes, furniture legs, and lead handles are all fair game again. On top of that, adolescent dogs have enormous energy, and if it’s not channelled, it finds an outlet — usually your skirting boards.
Why Is This Happening?
Three things converge during adolescence to create the perfect storm of regression.
Brain remodelling
The adolescent brain is reorganising. The limbic system (emotions, instincts, reward-seeking) is highly active, while the prefrontal cortex (impulse control, rational decision-making) is still developing. The dog experiences stronger emotional responses with less ability to regulate them. It’s the neurological equivalent of a car with a powerful engine and undersized brakes.
Hormonal surges
Increased testosterone in males can trigger more territorial behaviour, mounting, and reactivity. Females approaching their first oestrus cycle may become more sensitive, distracted, or moody. These hormonal changes amplify existing behavioural tendencies and can make previously manageable situations feel overwhelming.
Social and environmental awakening
Adolescent dogs become hyper-aware of their environment. Smells are more interesting. Other dogs are more exciting. Movement in the distance demands investigation. The world that was background noise at five months is suddenly vivid and competing fiercely for the dog’s attention. Your voice, your treats, and your cues have to compete with all of that.
How to Train Through Adolescence
The worst thing you can do during this phase is stop training. The second worst thing is punish the dog for normal developmental behaviour. Here’s what works.
- Lower your expectations temporarily. This doesn’t mean abandoning standards — it means accepting that the dog needs more support than it did at five months. If the dog could hold a stay for thirty seconds last month, work at ten seconds this month and rebuild. Meet the dog where the dog is, not where you think the dog should be.
- Go back to basics with high-value rewards. Kibble won’t cut it anymore. Diced chicken, cheese, freeze-dried liver, or whatever makes your dog’s eyes light up. During adolescence, you’re competing with the entire outside world for the dog’s attention. Your rewards need to be worth it. Don’t phase out food rewards yet — this is the worst possible time to try.
- Use a long line for recall work. A five- or ten-metre long line gives the dog some freedom while keeping safety under your control. Practise recall on the long line every walk. Reward generously when the dog returns. If the dog doesn’t come, reel in the line calmly — no yelling, no drama. Do not let an adolescent dog off lead in unfenced areas if recall is unreliable. One bad experience (bolting across a road, running up to a reactive dog) can set training back significantly.
- Train in low-distraction environments first. Your backyard. A quiet cul-de-sac. An empty oval at 6am. Build success in easy environments, then gradually add difficulty. Asking a teenage dog to perform a sit-stay outside a busy café is setting both of you up for frustration.
- Keep sessions short and fun. Five to ten minutes of focused, rewarding training beats thirty minutes of nagging. End while the dog is succeeding. If the dog is losing focus, stop. Play a scatter-feed game, do something easy the dog can win at, and call it a day.
- Increase physical and mental exercise. Adolescent dogs have enormous energy reserves. A fifteen-minute stroll around the block is not going to touch it. Longer walks, off-lead time in secure areas, sniff walks (let the dog lead with the nose), puzzle toys, scatter feeds, and training games all help drain the tank. A mentally and physically tired dog is dramatically easier to work with.
- Don’t punish the regression. Yelling, leash corrections, and punishment-based tools during adolescence are particularly harmful. The limbic system is already in overdrive — adding fear or pain on top of that can create lasting behavioural fallout. The 2020 Biology Letters study noted that dogs with insecure attachments to their carers showed worse adolescent regression. Punishing the dog weakens the attachment, which makes the regression more intense.
The Second Fear Period
Between roughly six and fourteen months, many dogs enter a second fear period (the first occurs around eight to ten weeks). During this window, the dog may suddenly become fearful of things that previously caused no concern — a wheelie bin on the footpath, a person in a hat, a dog the dog has met before.
The response can be startling. A dog that walked confidently past building sites last month might freeze, bark, or try to bolt from a parked truck this month. The temptation is to force the dog to “face the fear” or drag the dog past the scary object. Don’t. Flooding a fearful dog makes the fear worse.
Instead, create distance from the trigger, let the dog observe from a comfortable point, reward calm behaviour, and move on. If the fear is persistent, gradual desensitisation (the same approach used for reactivity) helps the dog relearn that the trigger is safe. Most second fear period responses resolve within a few weeks as the brain finishes that particular round of rewiring.
When to Get Professional Help
Most adolescent regression is manageable with patience, consistency, and the strategies above. But seek professional help if the dog’s reactivity is escalating (towards other dogs, people, or family members), if the dog is showing genuine aggression (not just teenage pushback), if anxiety is preventing the dog from eating, relaxing, or enjoying walks, or if you’re feeling overwhelmed and the relationship is suffering.
In Australia, your vet can refer you to a veterinary behaviourist. Qualified trainers through the Pet Professional Guild Australia or the Delta Society can help with structured adolescent training plans. Some training schools run specific “reactive rover” or “teenage dog” group classes designed for this exact phase — the Animal Welfare League and many private AU trainers offer them.
When to Get Professional Help
Most adolescent regression is manageable with patience, consistency, and the strategies above. But seek professional help if the dog’s reactivity is escalating (towards other dogs, people, or family members), if the dog is showing genuine aggression (not just teenage pushback), if anxiety is preventing the dog from eating, relaxing, or enjoying walks, or if you’re feeling overwhelmed and the relationship is suffering.
In Australia, your vet can refer you to a veterinary behaviourist. Qualified trainers through the Pet Professional Guild Australia or the Delta Society can help with structured adolescent training plans. Some training schools run specific “reactive rover” or “teenage dog” group classes designed for this exact phase — the Animal Welfare League and many private AU trainers offer them.
Frequently Asked Questions
Has my dog actually forgotten the training?
No. The training is still stored in the dog’s brain, but the adolescent brain prioritises novelty, exploration, and immediate rewards over obedience. The dog hasn’t forgotten — the dog is choosing not to respond because the limbic system is overpowering the prefrontal cortex. When the brain finishes rewiring, the trained behaviours typically return, often stronger than before.
Will desexing fix the regression?
Desexing can reduce some hormonal-driven behaviours (like mounting or territorial marking), but it won’t magically end adolescence. Brain remodelling and environmental awakening are independent of hormones. Desexing a dog during adolescence can help, but it’s not a cure for regression.
How long will the regression last?
Most dogs show the worst regression between eight and twelve months, with gradual improvement over the next six months. Large breeds can take longer. The regression is temporary, but the timeline depends on breed, individual temperament, and how consistently you train through it.
Should I stop letting my dog off lead?
If recall has become unreliable, yes. Use a long line instead. An adolescent dog that bolts, ignores you, or runs up to other dogs can create dangerous situations and reinforce bad habits. Off-lead privileges should be earned back through consistent training in safe, controlled environments.
Is this the age when dogs get surrendered?
Yes. Adolescence is a peak relinquishment age. Owners who don’t understand the temporary nature of regression often assume the dog is untrainable or aggressive. The 2020 Biology Letters study noted that dogs with insecure attachments showed worse regression, and insecure attachments are a risk factor for surrender. Getting professional support during this phase can prevent a permanent separation.
Asher, Harvey et al. (2020), “Teenage dogs? Evidence for adolescent-phase conflict behaviour and an association between attachment to humans and pubertal timing in the domestic dog,” Biology Letters — https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2020.0097 — 8-month obedience dip, carer-specific disobedience, insecure attachment and earlier puberty
Newcastle University / EurekAlert, “Adolescence is ruff for dogs too” (2020) — https://eurekalert.org/pub_releases/2020-05/nu-air051220.php — study summary, Dr Lucy Asher and Dr Naomi Harvey quotes, adolescence as peak relinquishment age
AKC, “Your Adolescent Puppy and Changes to Expect” — https://www.akc.org/expert-advice/health/adolescent-puppy-changes/ — secondary chewing phase, mental stimulation needs, continued obedience practice
Preventive Vet, “Tips for Managing the Teenage Dog Phase” — https://www.preventivevet.com/dogs/teenage-puppy-behavior — adolescence timeline by breed size, hormonal changes, high-value reward use, long line safety
RSPCA UK, “Managing Your Adolescent Puppy” — https://www.rspca.org.uk/adviceandwelfare/pets/dogs/health/adolescentpuppies — impulse control development, frustration behaviours, fear and anxiety in adolescence