If your six-month-old puppy suddenly acts like they have never heard a single command you have ever taught them, you are not imagining it, and you are not alone.
One day your dog is the star of puppy class, sitting perfectly and dropping instantly on cue. A few months later, the same dog looks at you like you are speaking a foreign language when you ask for the same behaviors. It is enough to make you wonder if you did something wrong.
You did not. What you are seeing is completely normal, and it has everything to do with what is happening inside your dog’s brain and body during this stage.
What Is Actually Happening
Canine adolescence often starts between six and twelve months and can last until about 18 to 24 months, with the exact timing varying based on your dog’s breed and size. Small dogs tend to mature faster, while larger breeds may stay in this phase well past their first birthday.
During this period, your dog is going through a massive developmental shift. According to the RSPCA, there are dramatic hormonal changes and a reorganization of the brain happening during canine adolescence. That is not an exaggeration. The canine brain is literally rewiring itself during this phase, and that process makes previously learned behaviors much less reliable.
Think about what happens during human puberty. Your brain is flooded with new hormones, you feel different, you act differently, and things that seemed simple suddenly feel harder. Dogs experience something remarkably similar.
The Hormone Surge
One of the most significant drivers of this behavioral shift is hormones. In intact male dogs, testosterone levels begin rising around four to five months and peak at roughly ten months of age at levels five to seven times higher than adult male dogs. Those levels do not settle back to adult baseline until approximately 18 months of age.
Female dogs are not exempt either. They experience estrogen and progesterone fluctuations during heat cycles that can affect their mood, sensitivity, and responsiveness. Together, these hormonal shifts create a perfect storm that can make your previously reliable training partner seem like a completely different dog.
This surge of hormones affects more than just behavior. It influences confidence, energy levels, and how your dog processes social information. An adolescent dog experiences the world differently than they did as a younger puppy.
Why Training Suddenly Falls Apart
The brain reorganization and hormone surge explain the what, but the why is equally important to understand.
During adolescence, your dog’s priorities are shifting. Where a younger puppy was primarily focused on you, their trusted caregiver, adolescent dogs become more interested in the environment around them. A 2020 study published in Biology Letters by researchers at the University of Nottingham and Newcastle University found that dogs around eight months old were less obedient to their owners’ commands but more responsive to strangers. That is not your dog choosing to ignore you. It is their developing brain prioritizing different information.
As Cornell’s Riney Canine Health Center explains in its guide to the teenage dog phase, the prefrontal cortex is still developing during adolescence, and that affects self-control, problem solving, and social interactions. This is the part of the brain that helps your dog think through consequences and respond to cues reliably. When it is still developing, your dog’s ability to self-regulate is naturally less consistent. You can read Cornell’s overview here.
This means that even if your dog genuinely knows a command, they may not be able to execute it as reliably when distractions are present. Your dog is not being stubborn. Their brain is still maturing.
This Is Not Your Fault
If you are feeling frustrated or embarrassed by your dog’s regression, take a breath. This is not a reflection of your training ability, and it is not a sign that your dog is broken or untrainable.
Puppy training before six months of age has real long-term value. A 2021 study published in Animals found that dogs who attended puppy training in the first six months had lower odds of later aggressive behavior, compulsive behavior, destructive behavior, and excessive barking than dogs that had not attended puppy training. You can read the PubMed record here. Early training builds a foundation that pays off well beyond adolescence.
But even the best early training does not make your dog immune to this phase. Adolescence creates a temporary regression that is biologically driven. The brain is reorganizing, the hormones are surging, and your dog’s attention is being pulled in new directions. None of that erases what they learned. It just makes it harder to access in the moment.
The important word there is temporary. What you are experiencing is a phase, not a permanent state.
What You Can Do Right Now
While you cannot speed up your dog’s brain development, there are concrete things you can do to navigate this phase more smoothly.
Go back to basics. Treat this like your dog is learning for the first time. Review commands in low-distraction environments before asking for reliability in more challenging situations. If your dog was rock-solid on stay in the kitchen, do not expect the same performance at a busy dog park. Build back up gradually.
Increase your reward rate. The American Veterinary Society of Animal Behavior recommends reward-based training methods as the foundation for dog training and behavior work, which fits this phase well because short, frequent sessions with high-value rewards tend to keep adolescent dogs more engaged than longer, frustrating ones. You can read that AVSAB guidance here.
Manage expectations. Accept that your dog will not be as reliable as they were a few months ago, and that is okay. Do not punish your dog for not responding. AVSAB warns against punishment-based methods because they can create fear, stress, and conflict rather than helping dogs learn calmly and clearly.
Increase exercise appropriately. Adolescent dogs often have lots of energy with less self-control to manage it. Regular walks, play, enrichment, and short training sessions can help take the edge off without turning every day into a marathon.
Protect your dog’s confidence. If your dog fails a command, do not repeat it over and over until they get it right. This creates a pressure situation that builds stress. Instead, ask for an easier behavior, reward heavily, and try again later.
Enroll in a refresher class. Many training facilities offer adolescent or teenage dog classes specifically designed for dogs in this phase. The change of environment and social aspect can re-engage a bored teenager, and a professional trainer can give you targeted feedback.
The Bigger Picture
The adolescent phase is challenging, but it is also an important developmental period. The choices you make now matter for your dog’s long-term behavior and your relationship with them.
The key is to stay patient, stay consistent, and remember that this regression is temporary. Your dog is not trying to frustrate you. They are going through a biological transformation that affects every aspect of their behavior.
Many dogs emerge from adolescence by around 18 to 24 months with a more mature brain, more stable hormones, and a much more reliable response to training. The dog who ignored your recall at ten months may become the dog who comes running effortlessly at two years.
Stay the course. The work you put in now pays off for years to come.
Samantha Tilton
I catch the things that are easy to miss. The small changes, the quiet signs, the details hiding in plain sight. I co-founded The Daily Dog because the best thing you can do for your dog is pay attention, and I write to help you know what to pay attention to.
