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When Do Dogs Stop Growing

↯ Key takeaway points

  • When a dog stops growing depends on its breed, with toy breeds stopping at around 6 months and giant breeds taking up to 3 years.
  • Medium breeds, such as English Bulldogs and Springer Spaniels, may take around 12 to 24 months to reach their full size.
  • Puppies need a high-quality, high-calcium, high-protein diet to develop their bones and muscles.
  • Genetics, nutrition, and hormone levels can also play a role in a puppy's growth rate.
  • While there are ways to estimate a puppy's full size, it is not always accurate and varies from puppy to puppy.
Written by Jay
BsC (Hons) Animal Behaviour & Welfare graduate with a passion for advocating for misunderstood animals.
Zoo and wildlife doctor in veterinary medicine passionate about animal welfare and preventive medicine.
Published on
Saturday 12 December 2020
Last updated on
Friday 12 May 2023
when do dogs stop growing
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Watching your puppy grow is an exciting part of puppy ownership. Dogs stop growing at different ages, typically ranging from six months to three years old, depending on the breed. While some puppies may be smaller or weaker than their littermates, it does not necessarily mean they will have lifelong health problems. 

Dogs stop growing anywhere from six months old to three years old. The precise amount of time it takes varies depending on your puppy’s breed. Some dogs are also naturally weaker, we usually call them the runts of a litter.

Want to find out how much longer your little one needs to grow? If you want to learn more about your puppy’s growth rate, read on!

When Do Dogs Stop Growing: Answering By Breed Size

When it comes to the growth of dogs, the time it takes for them to reach their full size depends on their breed. Smaller toy breeds can reach physical and sexual maturity more quickly than larger breeds. For instance, breeds like Toy Poodles, Pomeranians, Papillons, Miniature Pinschers, and Chihuahuas will typically stop growing at six months to a year old. 

Meanwhile, medium breeds like the Basset Hound, English Bulldog, Staffordshire Bull Terrier, and English Springer Spaniel take anywhere from 12 to 24 months to reach their full size. Large breeds like the Alaskan Malamute, Belgian Malinois, Borzoi, Cane Corso, Rottweiler, and German Shepherd usually finish growing between 16 to 24 months. Finally, giant breeds like the Bullmastiff, Great Dane, Irish Wolfhound, and Tibetan Mastiff can take up to 30 months to reach their full size.

It’s important to note that these timeframes are general guidelines, and the growth rate of individual dogs may vary. However, it’s essential to monitor the growth of your pup and provide them with a healthy diet and plenty of exercise to ensure that they reach their full potential.

Toy Dog Breeds

Toy breeds are the smallest of all, and will reach physical and sexual maturity the fastest. Depending on the breed, your toy dog will stop growing at anywhere from six months to one year old. But which breeds classify as toy breeds? Toy Poodles, Pomeranians, Papillons, Miniature Pinschers, and Chihuahuas are just a few of the many tiny breeds from around the world!

The Chihuahua is one of the quickest to grow, reaching adult size as soon as six months old in some cases. The Toy Poodle is a close second, reaching adult size at six to seven months old. Miniature Pinschers need an extra few months, growing to an adult height at 10 to 11 months of age. Finally, breeds like the Pomeranian and Papillon reach adult size at 12 months.

Medium Dog Breeds

Medium dog breeds have more growth to complete than toy breeds, and consequently, take longer to reach their full size. Depending on your dog’s breed, they may stop growing anywhere from 12 to 24 months of age. But which breeds do we consider to be medium? Medium dog breeds include the Basset Hound, English Bulldog, Staffordshire Bull Terrier, and English Springer Spaniel.

Staffordshire Bull Terriers sometimes reach their adult height at 12 months old, but others take up to 18 months to become fully grown. Similarly, the English Bulldog typically reaches adult size at 18 months old. In contrast, Basset Hounds and English Springer Spaniels take up to 24 months to stop growing.

Large Dog Breeds

Your loveable large breed pup needs even more time to grow. Depending on their breed, your large dog spends anywhere from 16 to 24 months growing to its full size. Large dog breeds include the Alaskan Malamute, Belgian Malinois, Borzoi, Cane Corso, Rottweiler, and German Shepherd. Some breeds are difficult to pigeonhole into one classification – breeds like the Labrador Retriever are sometimes classified as “medium to large” dogs.

The boisterous Belgian Malinois spends anywhere from 16 to 19 months growing to their full size. Similarly, the Cane Corso finishes growing at around 19 months old. Breeds like the Alaskan Malamute, Rottweiler, and German Shepherd typically reach adult size in the ranges of 18 to 24 months.

Giant Dog Breeds

Is your pup destined to become a towering tyke? The Bullmastiff, Great Dane, Irish Wolfhound, and Tibetan Mastiff are considered to be giant dog breeds. In contrast to a toy breed, which can finish growing by six months old, a giant breed will continue to grow far past 12 months old. Depending on the breed, your giant dog can continue to grow until they are 12 to 30 months old!

Your Great Dane can finish growing at 18 to 24 months old. Similarly, a Tibetan Mastiff might finish growing at 19 to 24 months old. Irish Wolfhounds reach their adult height at 24 months old. Finally, the Bullmastiff stops growing at around 30 months old.

Factors that Affect When Your Puppy Stops Growing

Aside from your puppy’s breed, there are three main factors that determine how fast and how much your puppy grows. These factors are nutrition, genetics, and hormone levels.


Nutrition is crucial for your pup’s growth, including their bones, muscles, teeth, fur, and internal organs, as well as their mental development. Puppies require more calcium, protein, and fats than adult dogs because they are growing rapidly. 

About half of the calories a puppy consumes are used for their growth and skeletal development, so they need almost three times the amount of calcium that adult dogs need. Their food should contain 22.5 percent dry matter protein, compared to 18 percent for adult dogs. Without sufficient protein and calcium, your pup’s bones and muscles won’t develop at a normal pace.

If you have a giant breed puppy, they require a different type of puppy food. Their food should contain less fat and calories, less calcium and phosphorus, and a careful balance of calcium to phosphorus. Too much calcium can cause skeletal malformations.


Genetics play a significant role in how fast your puppy grows, and not all puppies grow at the same rate, even if they receive the same diet. Some diseases that affect growth are inherited at birth, so it’s essential to check in with your vet if you suspect that your puppy is growing abnormally.

As well as this, some diseases that influence growth are inherited at birth. For example, congenital growth hormone deficiency, which is most common in German Shepherds, is an autosomal recessive inherited condition. If you suspect that your puppy is growing abnormally, be sure to check in with your vet.

Spay/Neuter History

Spaying and neutering can affect your dog’s growth trajectory slightly. Neutering a puppy between 22 and 37 weeks old may cause a slight upward shift in its growth trajectory, but it’s short-lived and soon returns to its original trajectory. Neutering a puppy before 22 weeks old may cause a more pronounced upward shift. Dogs neutered after 37 weeks old may experience a slight decrease in their growth trajectory.

In summary, besides your puppy’s breed, nutrition, genetics, and hormone levels play a crucial role in how fast and how much your puppy grows. Understanding these factors can help you give your puppy the best possible start in life.

when dogs stop growingDogs grow at different rates.

When Dogs Stop Growing – FAQ

Still wondering when dogs stop growing? If you have any more questions or concerns, our Frequently Asked Questions section is here to help. If in doubt, always contact your vet for advice.

At what age is a dog full grown?

Wondering when your furry friend will reach their full size? The answer depends on their breed! Smaller toy breeds like Chihuahuas can reach their adult size in as little as six months, while larger breeds like Rottweilers and Bullmastiffs can take up to three years. Medium breeds like English Bulldogs fall somewhere in between, usually reaching their adult size around 18 months old.

Can you tell how big a puppy will get?

There are a few ways to estimate how big your puppy will get. Knowing their breed is the most reliable method, but if you have a mixed breed, it can be a bit trickier. In these cases, measuring their paws can sometimes give you a clue – larger paws generally mean a larger dog. However, this method isn’t always accurate, as puppies can have sudden growth spurts that throw off their paw-to-body ratio.

At what age do female dogs stop growing?

Female dogs usually stop growing around the same time as males, typically between six months and three years depending on the breed. However, females tend to mature faster and are usually a bit smaller than males of the same breed.

How much will a dog grow after 6 months?

By six months old, most puppies’ growth rate slows down, but they will continue to fill out in muscle and weight over the next few months. Regardless of breed, your pup should have all of their adult teeth by this age and some may even become sexually mature.

If you have any questions about your puppy’s growth or development, don’t hesitate to reach out to your veterinarian for advice. And remember, providing your puppy with proper nutrition is key to ensuring their healthy growth and development!

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