One minute you’ve got a puppy who sits, waits, and comes back every single time you call. The next minute – usually somewhere around eight or nine months old – you’re stood in the middle of a field shouting a name that means absolutely nothing to the dog who’s twenty feet away, sniffing a hedge, tail up, completely ignoring you. If that sounds familiar, take a breath. You haven’t done anything wrong, and you definitely haven’t ruined your puppy. What you’re seeing has a name: puppy training regression, and it’s one of the most common, and most misunderstood, stages in a young dog’s life.
In fifteen years as a dog behaviourist, I’ve had more calls about this exact issue than almost anything else. A dog that was an absolute dream at four, five, six months old suddenly can’t hold a sit, won’t come back on the whistle, drags you down the street on the lead, and seems to have forgotten every single thing you ever taught it. Owners message me convinced they’ve done something terribly wrong. They haven’t. Their dog has walked straight into a fear period and adolescence at the same time, and nobody warned them it was coming.
Let’s talk about what’s actually going on in that head of theirs, why it happens, and what you can do about it.
What Is Puppy Training Regression?
Puppy training regression is exactly what it sounds like: a dog who previously knew, and reliably performed, certain behaviours suddenly stops doing them, or does them far less reliably. It tends to show up around the six to nine month mark and can rumble on, in waves, until the dog is somewhere between eighteen months and two years old, depending on breed and size.
It isn’t a sign that your training “didn’t work,” and your dog isn’t being deliberately naughty or disrespectful. This stage definitely isn’t permanent, either. Puppy training regression is a completely normal, if frustrating, part of canine adolescent development, driven by hormonal changes, brain development, and a second fear period that catches almost every owner off guard.
If you’ve found yourself typing “why is my 9 month old puppy ignoring me” or “puppy suddenly stopped listening” into Google at eleven o’clock at night, you are not alone, and you’re in exactly the right place.
The Science Behind Puppy Training Regression: Understanding the Dog Fear Period
Dogs go through two recognised fear periods during development. The first happens early, somewhere around eight to eleven weeks old, and most new owners get some warning about that one. That second one, the one that really catches people out, happens much later, typically somewhere between six and fourteen months of age, and it can land at a different time for every individual dog.
During a fear period, dogs become more sensitive to things that wouldn’t have bothered them a few weeks earlier. A bin bag on the pavement, a dog they’ve walked past a hundred times, a hand reaching down to clip the lead on. Any of it can suddenly trigger a startled, worried, or avoidant response. This isn’t your dog being difficult. It’s a normal part of brain development, and organisations that research canine behaviour and development, including the American Kennel Club, describe this stage as a biologically driven period of heightened sensitivity that helps young dogs learn caution as they move toward independence.
At the same time this is happening, your dog is also going through puberty. Hormones are shifting, the adolescent brain is pruning and rewiring itself in much the same way a teenager’s does, and impulse control genuinely takes a back seat for a while. Put a fear period and a hormonal, adolescent brain together, and you get a dog who looks, sounds, and occasionally behaves like a completely different animal to the one you had at five months old.
When Does Puppy Adolescence Start and End?
Most dogs enter adolescence around six months and don’t fully come out the other side until somewhere between eighteen months and three years old, with larger breeds often taking longer to mature than smaller ones. It rarely happens in one smooth line. Expect peaks and troughs: a few brilliant weeks followed by a wobble, then another good stretch, then another dip. If you’re wondering whether is puppy regression normal, the honest answer is yes, and it would actually be more unusual if your dog sailed through adolescent dog behaviour without a single hiccup.
Why Is My 9 Month Old Puppy Ignoring Me?
This is the question I get asked more than any other, usually from an owner who is exhausted, a bit embarrassed, and genuinely worried they’ve somehow broken their dog. Here’s what’s really going on: it’s puppy training regression, and it shows up in a few very recognisable ways.
Puppy Recall Regression: Why Your Dog Won’t Come Back Anymore
Recall is one of the first things to fall apart during teenage dog behaviour, and there’s a good reason for it. Recall was never really about the word “here” or the whistle you bought. It was about your puppy finding you more interesting and more valuable than whatever else was going on. At five months old, most of the world was still a little bit scary and you were the safest, most exciting thing in it. At nine months, your dog has had a few more months of confidence, the great outdoors has become far more interesting, and their brain is genuinely more distractible thanks to the hormonal and neurological changes we’ve just covered.
So when you’re asking why has my dog stopped coming back, the answer usually isn’t disobedience. It’s that, in that moment, you’ve become less interesting than the smell in the hedge, the dog on the horizon, or their own racing thoughts. Adolescent dog recall is one of the clearest signs of a fear period and adolescence overlapping, and dog ignores recall now is one of the most common phrases I hear from clients who, a few months ago, had a puppy who came back every single time.
Teenage Dog Pulling on the Lead Again
If your dog walked beautifully on the lead a few months ago and is now hauling you down the road like a sled dog, you’re not imagining it and you’re not losing your touch. Teenage dog pulling on lead is incredibly common, partly because adolescent dogs are stronger and more confident, and partly because a nervous or overstimulated dog going through a fear period will often surge towards or away from things rather than walk calmly past them. Puppy pulling again, or dog pulling on lead again at this age, is rarely about manners. It’s much more often about arousal, worry, or simply an adolescent body that hasn’t quite caught up with an adolescent brain yet.
Puppy Biting Again and Barking More
Mouthing and nipping that you thought you’d left behind at twelve weeks can also reappear. It’s usually a stress response rather than true aggression. An adolescent dog who’s overwhelmed, overtired, or under-stimulated mentally will often go back to using their mouth to communicate, because it’s a well-worn pathway from puppyhood. Barking more on walks or at the door tends to follow the same pattern: a more reactive nervous system, working overtime during a fear period, announcing every single thing it notices. If your dog suddenly seems distracted on walks, jumpy, vocal, or generally somewhere else entirely, this is almost always why.
“Have I Ruined My Puppy?”
I want to answer this one directly, because I hear it constantly, usually from someone close to tears on the phone. No. You have not ruined your puppy. A dog going through a fear period and adolescence at the same time is not a reflection of bad ownership. It’s biology. Even dogs raised by the most experienced, patient, switched-on owners go through exactly this stage, because it’s wired into canine development, not caused by anything you did or didn’t do.
It can genuinely feel like you’re wondering why has my puppy forgotten everything, or thinking that puppy training not working anymore is somehow a reflection on you. It isn’t a failure on your part, it’s puppy training regression, and it’s textbook for this age. What matters now isn’t guilt, it’s response. How you handle the next few months will shape how your dog comes out the other side, and calm, consistent, force-free handling is exactly what gets a dog through a fear period with their confidence intact.
What Might Have Been Missed Before 16 Weeks (And Why It Fuels Puppy Training Regression)
Sometimes a rocky adolescence does shine a light on a few gaps from those first sixteen weeks, not because anyone did anything wrong, but because most new owners simply aren’t told how much groundwork happens in that tiny window. Genuine exposure, not just presence, to a wide variety of people, dogs, surfaces, sounds and situations; well-practised impulse control games; and teaching a puppy to cope with mild frustration rather than removing every trigger, all pay dividends later. If any of that was thin on the ground before sixteen weeks, adolescence tends to expose it, because the dog now has both the confidence and the independence to test the gaps.
I go into this in a lot more depth in Nobody Tells You This: The Real Truth About Getting a Puppy Right, which covers exactly what happens in those critical early weeks and why it matters so much later on. The good news is that it’s never too late to fill those gaps in. Dogs are learning all the time, not only before sixteen weeks, and an adolescent dog is still very much a dog who can learn.
Is Puppy Training Regression Normal? What to Do About It
Yes, completely. Here’s how I’d tackle it with a client, step by step, if their dog was suddenly ignoring commands or had stopped listening on walks.
Go Back to Basics
Drop the difficulty right down. If recall has gone out the window, that doesn’t mean more shouting or a longer line straight away, it means shorter distances, higher value rewards, and far fewer distractions while you rebuild the habit. Treat your nine month old like they’re learning “come” for the first time, because in a sense, they are. The dog in front of you now is a physically and mentally different animal to the one you trained at four months old.
Manage the Environment Rather Than Fight It
If your dog is struggling with recall around other dogs, use a long line so they physically can’t rehearse ignoring you. If lead pulling has crept back in, shorten your walks for a while, choose quieter routes, and use the right kit, a well-fitted harness rather than a slip lead or collar, to protect you both while you retrain. Management isn’t giving up. It’s stopping your dog from practising the very behaviour you’re trying to change.
Keep Training Sessions Short, Positive and Frequent
Little and often beats one long, frustrating session every time, especially with an adolescent brain that’s already juggling a lot. Five minutes, several times a day, with rewards your dog genuinely wants, will get you further than twenty minutes where everyone ends up fed up. If you feel like why won’t my puppy behave anymore, it’s often simply that the training has become too long, too repetitive, or not rewarding enough for a brain that’s now easily distracted.
Protect Them Through the Fear Period
If your dog suddenly seems worried about something they used to walk past without a second glance, don’t force it. Give them distance, let them look, reward calm behaviour, and move on. Flooding a dog with something that frightens them during a fear period can create a lasting negative association, so patience here really does pay off. This one change alone often resolves a dog who has seemed suddenly distracted on walks or reluctant to move forward.
When Does Puppy Training Regression End?
Most owners start to see the fog lift somewhere between eighteen months and two years, though giant breeds can take a little longer still. You’ll notice it gradually rather than all at once: a few more good days than bad, recall that holds up a bit longer, a dog who settles a bit quicker after excitement. Puppy training regression doesn’t last forever, even when it feels like it during month three of the wobble. Dog regression at 9 months is very often the toughest patch, simply because it’s the point where the fear period and the adolescent growth spurt tend to overlap most heavily.
Getting Extra Support Through Puppy Training Regression
You don’t have to muddle through puppy training regression alone, and honestly, most owners get on a lot better with a bit of structure behind them.
If you want a solid, free starting point, grab my free training guide here. It walks you through exactly the kind of foundation work that makes the biggest difference during this stage.
If your dog’s regression has tipped over into genuine reactivity, barking, lunging, or growling at other dogs or people on walks, my reactivity guide is written specifically for this, using the same calm, force-free approach I use in one-to-one sessions.
And if you’d rather start from scratch with a clear, day-by-day structure, which works brilliantly even if your dog isn’t a brand new puppy, since it resets the foundations, the 30 Day Puppy Plan covers exactly that.
If you’re still expecting a puppy, or have a young one and want to avoid as many of these gaps as possible before sixteen weeks, my puppy book walks through it all in plain English, with no jargon. It’s also well worth a read if you’re partway through adolescence, so you understand exactly how you got here and where you’re heading next. For more on why professional guidance can make such a difference when things feel stuck, have a look at Fixing Dog Behaviour Step by Step.
Final Thoughts
Puppy training regression feels enormous when you’re in the middle of it, but it’s a stage, not a life sentence. Your dog isn’t broken, your training wasn’t wasted, and you absolutely have not ruined your puppy. What you’re dealing with is a normal, biologically driven fear period colliding with adolescence, and with calm, consistent, force-free handling, your dog will come out the other side every bit as good as, and usually better than, the puppy you started with.
If you’d like some hands-on help getting through this stage, whether that’s a wobbly recall, lead pulling, or a dog who suddenly seems like a stranger on walks, get in touch through Simply Dog Behaviour. I’d love to help you and your teenage dog find your way back to each other.