Tips for Managing a 1-Year-Old, 8-Month-Old Dog’s Behavior and Training

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Your 20-month-old dog is in what many trainers call the “teenager” phase: past the sweet, compliant puppy stage, but not yet a settled adult. This is the age when many owners feel overwhelmed or frustrated—even those who’ve done everything “by the book.” The most important thing to know? The behaviour you see now isn’t as permanent as it feels. With the right adjustments, you can get through this stage and help your young dog become the companion you want.

Why 1 Year and 8 Months Is a Challenging Age for Dogs

Dogs between 12 and 24 months are navigating a unique period of mental and physical development. Hormones are still shifting, especially in intact dogs. Even neutered or spayed dogs show bursts of energy, boundary-testing, and unpredictable behaviour. Think of it as adolescence in humans: your dog may suddenly “forget” commands, become more reactive on walks, or start chewing things they ignored for months.

Breed plays a huge role. For example, many working breeds (Border Collies, German Shepherds, Retrievers) don’t reach full maturity until 2-3 years, while smaller breeds may settle earlier. If you’re seeing new challenges now, you’re not alone—this is a common pain point for owners of medium and large breeds, especially those with high drive or intelligence.

Common Problems at This Age—and What Actually Works

Most owners in your shoes report a mix of these issues:

• Sudden disobedience or “selective hearing”
• New or worsening leash pulling
• Destructive chewing, digging, or counter-surfing
• Overexcitement around people or other dogs
• Regression in housetraining or crate behaviour

Let’s break down what’s going on, and which solutions match real-world use cases.

Choosing the Right Approach for Your 20-Month-Old Dog

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How to Tell If Your Dog’s Behaviour Is “Normal” at This Age

Many owners panic when their formerly well-behaved dog starts ignoring cues or acting out. The truth is, most dogs between 12–24 months will test boundaries, especially if they’re not getting enough mental and physical stimulation. What’s not normal? Sudden aggression, self-injury, or dramatic changes in appetite or elimination habits. Those warrant a check-in with your vet or a certified behaviourist.

If your dog is simply more energetic, mouthy, or stubborn, that’s textbook adolescent behaviour. Consistent routines, clear boundaries, and patience are your best allies. Owners of large, high-drive breeds should expect this phase to last until around 2.5 years—sometimes longer.

Breed-Specific Notes: Why Your Dog’s Genetics Matter Now

Adolescence looks very different depending on your dog’s breed and mix. For example:

• Herding breeds (e.g. Collies, Aussies): May develop obsessive behaviours like chasing, nipping, or herding people/pets. Need structured jobs and advanced obedience work.
• Retrievers and sporting breeds: High energy, likely to chew and carry objects. Benefit from retrieval games, scent work, and “find it” training.
• Guarding breeds (e.g. Mastiffs, Rottweilers): May show increased territorial behaviour or suspicion of strangers. Socialisation and impulse control are critical at this age.
• Toy breeds: Often mature faster, but may become “barky” or stubborn. Short, positive sessions work best.

Mixed breeds can show traits from any ancestor. If your dog’s behaviour feels extreme, look up the breed standard via the AKC’s breed profiles for insight into what’s typical.

What to Do When Training Plateaus or Regresses

Regression is normal at this age. Dogs may “forget” recall, stop responding to sit or stay, or act like they never learned leash manners. This isn’t stubbornness—it’s developmental. The solution isn’t to punish, but to reinforce the basics:

• Go back to training in quiet, low-distraction environments for 2–5 minute sessions.
• Use high-value rewards (cheese, cooked meat) for reliable recall.
• Practice impulse control games: “wait” at doorways, “leave it” with dropped food.
• Keep sessions short and frequent. A bored adolescent dog tunes out quickly.

Stuck? Many owners find a few sessions with a positive-reinforcement trainer set them back on track. View available options for trainers near you.

Safe Exercise and Mental Stimulation for a 20-Month-Old Dog

At this age, most dogs need at least 60–90 minutes of physical activity daily—more for working breeds. Off-leash play in a secure area, running, swimming, or structured games (like fetch or tug) burn energy and reduce frustration. Just as critical: mental work. Puzzle feeders with 10–20 minute engagement time, beginner scent training, or teaching new tricks tire your dog out in ways a walk can’t.

Don’t overlook safety: growth plates in large and giant breeds may not close until 18–24 months. High-impact activities (like agility or running on pavement) are safest after your vet gives the green light. Check current prices for interactive toys and enrichment tools tailored for adolescent dogs.

Common Owner Mistakes With Adolescent Dogs

It’s easy to fall into these traps:

• Inconsistent rules: Allowing behaviours “sometimes” confuses your dog. Stick to clear boundaries, even if it feels strict.
• Underestimating exercise needs: A 1-year, 8-month-old Labrador or Shepherd may need 2–3 hours of activity to be truly settled.
• Neglecting mental work: Physical exhaustion alone won’t solve boredom-based misbehaviour.
• Getting frustrated: Yelling or harsh corrections can increase anxiety and slow progress. Reset, breathe, and try again.

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When to Seek Professional Help

Certain behaviours—like sudden aggression, severe separation anxiety, or compulsive self-harm—are red flags that require expert intervention. A veterinary behaviourist can rule out medical causes and tailor a plan. For most adolescent “naughtiness,” though, a skilled positive trainer or structured group class is enough. Don’t wait until you’re at your wit’s end; early intervention leads to better outcomes.

For a deeper dive into canine behaviour, the Wikipedia entry on dog behaviour offers science-backed context on developmental stages.

FAQ: Real Answers for Owners of 1 Year, 8 Month Old Dogs

Opinionated Take: What Matters Most Right Now

The “teenage” phase is the single most challenging—and most misunderstood—period in a dog’s life. Your 1 year, 8 month old dog isn’t broken, stubborn, or hopeless; they’re growing up. Double down on consistency, invest in mental as well as physical exercise, and don’t hesitate to ask for help if you’re stuck. This stage will pass, and the work you put in now pays off for years to come.