When Does Your Puppy Become an Adult Dog?

Last updated on: Jan 17, 2024

By: Stephanie Dunne

Adult Golden Retriever Close-up Photo

Have you ever wondered when your puppy will grow up? Puppies are adorable and full of energy, but they won't be small forever. As they grow, you'll notice changes in their behavior and appearance.

We'll look at things like how big they get, when puppies start to calm down, and other signs that show they are not little puppies anymore. Let's dive into understanding your puppy's development.

When Is a Dog Not a Puppy Anymore?

Generally, dogs are considered adult when they reach about 1 to 2 years of age.

However, it's a bit tricky to pinpoint the exact moment when a puppy becomes an adult dog. It can vary a lot from one dog to another, depending on the dog's breed and size.

  • For small breeds, like Chihuahuas or Dachshunds, puppies may be considered adults by the time they're about 1 year old.
  • Medium breeds, like Beagles and Bulldogs, might take a bit longer, maybe up to 1 and a half years.
  • For large breeds, like Golden Retrievers and German Shepherds, the puppy phase can last until they're around 2 years old.
  • And for giant breeds, like Great Danes or Saint Bernards, they might not be fully grown until they're 2.5 or even 3 years old!

But it's not just about age. Dogs also show they're growing up in other ways. They might start acting more mature and less like a playful puppy. Some dogs might calm down a bit, listen better, and not be as wild as they were when they were little. Each dog is unique, so watch for changes in your dog to best gauge their growth.

8 Signs That Your Dog Is Growing Up

There are several signs that indicate that your puppy is transitioning to an adult dog.

  1. Losing Puppy Teeth. Around 4 to 6 months of age, your puppy will start to lose their baby teeth, and their adult teeth will come in. This is a big sign they're growing up!
  2. Not Chewing Everything Anymore. Puppies love to chew on everything! But as they grow, this habit usually slows down. When your dog starts chewing less, it's a sign they're maturing.
  3. Eating Less. Young puppies eat a lot because they're growing so fast. As they get older, their appetite might decrease because their growth is slowing down.
  4. Calming Down. Puppies are known for their high energy, but as they grow, they often start to calm down. If your dog isn't as hyper as they used to be, they might be leaving their puppy days behind.
  5. Getting Their Adult Fur. Puppy fur is super soft. As they grow into an adult, their coat will change. It might become thicker, coarser, or change color slightly.
  6. Fewer Accidents. If you've been consistent with house training, an older puppy will have fewer accidents in the house. This shows they're gaining control and understanding the rules better.
  7. Not Growing Bigger Anymore. Once your dog stops growing taller and longer, it's a clear sign they've reached their adult size.
  8. Behaving Differently Around Other Dogs: Puppies often play without thinking about boundaries. An adult dog will have better social skills and may act differently when meeting other dogs.

These signs can vary from dog to dog, but they're helpful indicators of your puppy's journey to adulthood.

When Do Puppies Stop Growing?

Most puppies grow the most in their first six months. However, the time it takes for them to reach their full size depends a lot on their breed.

  • Small breed puppies, like Yorkshire Terriers or Pomeranians, often finish growing by the time they are 6 to 8 months old. They start small and don't have as far to go to reach their adult size.
  • Medium breeds, such as Cocker Spaniels or Bulldogs, stop growing around 12 months of age. They have a bit more growing to do than small breeds, so it takes a little longer.
  • Large and giant breeds have the most growing to do and can continue to grow until they are 18 months to 2 years old.

It's not just about getting taller, either. After a puppy reaches its full height, they might still fill out more. This means they might get a bit heavier and more muscular as they turn into adult dogs.

A good way to tell if your puppy is still growing is by their paws. Puppies that are going to get bigger often have paws that seem a bit too big for their bodies. It's like they have to grow into their paws!

The Different Stages of a Dog's Life

Like people, dogs go through different life stages, each with its own unique joys and challenges.

  1. Puppyhood. This is the stage you're probably most familiar with. It starts when they're born and lasts until they're about 6 to 18 months old, depending on the breed. Puppyhood is full of learning and exploring. It's when you'll teach them basic commands and house training. Puppies in this stage are usually very playful and curious. We've discussed the puppyhood stage (or stages!) in a separate article.
  2. Adolescence. This stage begins around 6 to 18 months of age, when your dog reaches sexual maturity, and can last until they're about 2 to 3 years old. During this time, your dog might test boundaries and be more energetic. Continue training and socialization during adolescence to help your dog learn good behaviors.
  3. Adulthood. Adult dogs are typically more settled and predictable than puppies or adolescents. This stage usually starts around 1 to 3 years of age and lasts until they're about 6 to 8 years old. Adult dogs often have a well-established routine and behavior patterns. It's a great time to enjoy a stable and rewarding relationship with your dog.
  4. Senior Years. Dogs enter their senior years at different ages. Small breeds might not become seniors until they're around 10-12 years old, while large breeds might be considered seniors by 6-8 years old. Senior dogs often slow down and may have different health needs. This stage is a time for gentle care and understanding as they age.

Feeding Your Growing Dog

As your dog grows from a playful puppy to a mature adult, their dietary needs change too. Here's how you can adapt your dog's diet through their life stages:

  1. Puppy Stage: Puppies need a lot of energy and nutrients to support their rapid growth and high activity levels. Look for puppy-specific food that is rich in protein and essential nutrients.
  2. Transition to Adult Food: When your dog is about 80% of their expected adult size, it's time to start transitioning to adult dog food. Small breed puppies might move to adult food by 9-12 months, while larger breeds might continue with puppy food until they are 18 months to 2 years old. This transition should be gradual over a week or so. Mix in increasing amounts of adult food with the puppy food to avoid upsetting their stomach.
  3. Adult stage: Adult dogs need a balanced diet that maintains their health without overfeeding, as they are less active than puppies. The right adult dog food will have a good balance of protein, carbohydrates, fats, vitamins, and minerals.
  4. Senior Dogs: As dogs get older, their metabolism slows down. Senior dog food is often lower in calories but still provides essential nutrients. Some senior dogs may need food that's easier to chew or digest.

Check with your vet before making any significant changes to your dog's diet, especially if there are any health concerns.

Fresh water should always be available, regardless of the life stage. Find out if your puppy is drinking enough water.


Raising a puppy to adulthood is rewarding. Each life stage brings its joys and challenges. By understanding and adjusting to these stages, you can ensure a happy, healthy life for your dog. Cherish every moment, from the playful puppy days to the wise senior years.

Check out our article on how much sleep your puppy really needs.

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