A very enjoyable aspect of puppies is watching their development.

However, like other animals, dogs eventually reach their maximum size and stop growing.

Small breeds stop growing at approximately 6 to 8 months old. Medium breed puppies typically attain adult size by approximately 12 months. Large breed dogs cease to grow around 12-18 months.

Large breed puppies take longer to reach their maximum size due to their larger bones requiring a longer time to grow. But, there’s plenty of room for wiggles as certain breeds stop growing earlier or later than a one-year mark.

We’ll discuss these variations and the factors that affect your dog’s development from puppyhood through adulthood.

Key Takeaways: When Do Dogs Stop Growing?

• Most of the time, the pets stop growing around the ages of 6 to 18 months old. Generally speaking, smaller breeds stop growing at a younger age than larger breeds.
• A variety of factors can impact the amount of time the course of your dog’s development to expand. However, the two primary aspects are likely to be your pup’s genetics and the food you give your dog.
• Neutering and spaying could be a small impact on the final size of your dog. These variations are insignificant and only apparent when you look over the mountains of information.

How Do Puppies Grow, Anyway?

In terms of anatomy, dogs develop similarly to the extent as human children do, particularly when it comes to size.

It’s simple to observe the development of your puppy’s muscles as well as other soft tissues. After all, muscles grow over the course of a dog’s lifetime. Some mature dogs may “bulk up” if put through an exercise program that includes resistance training and appropriate nutrition.

But bones aren’t the same. They don’t grow to any extent in adulthood, and it isn’t easy to imagine how they expand in size at the beginning of your pet’s lifespan.

Instead of developing in a generalized way covering the whole bone, long bones develop from two distinct locations known as growing plates. These are found at both ends of the bones, and the growth plates are cartilaginous zones in which new tissue grows.

When new tissue develops, these growth plates tend to be flexible and soft in the pup hood.

As the new tissue gets older, it becomes hardened and becomes calcified, eventually turning into bone. Once the cells stop creating new tissue and are completely calcified, they’re called “closed,” which signifies that they have stopped growing and that bones have reached their ultimate size.

The growth plates are very fragile and prone to damage. It is, therefore, crucial to keep pups from engaging in too much exercise, which could cause damage to the growth plates. It’s also not a good idea to allow puppies to jump to great heights, for example, jumping off or onto couches.

Size and Breed-Related Puppy Growth Factors

It’s been discovered that smaller dogs die faster than large dogs.

This is understandable, considering that larger breeds tend to grow more from the time they’re born and the day they cease growing than small breeds.

Take, for instance, the fact that Chihuahua pups are born with a weight of approximately 5 ounces. They then grow to about 5 pounds or so by maturation. This means that they grow in size by about 15.

However, the Great Dane puppy weighs about 1 pound when born and up to 100 pounds at the time of maturity.

This means they show 100-fold differences in size throughout their lives (200-pound Great Danes have twice as much growth!).

Since it takes time to transform the food into new tissue, large breeds need to grow for more time in comparison to their smaller cousins.

On an average basis, smaller breeds usually cease to grow by the time they are 6-8 months old. However, the giant breeds increase their size until they reach twelve to 18 months old.

The larger breeds may be quite costly since an ideal-sized puppy mattress will not last long with a small Newfoundland.

It is something you should be aware of when choosing a crate for your dog. If you are unsure, you might be better off selecting an extra-large crate and using separators to ensure the space is adequate until your dog grows and requires more space!

Other factors that alter Puppy Growth Rate

In addition to your dog’s breed, other variables could affect the speed of its growth and ultimate size. The two most significant of these are:

   1. Genetic Differences

Every dog is born with a distinct genetic code, which can greatly affect the length of its growing period along with its build and even size as an adult.

Certain genetic traits are passed on from one parent to the next. Some traits are passed down from parent to puppy, while others are caused by the random variations that occur in DNA recombination.

This implies that the puppies of large parents could have a longer period of growth and larger potential size; however, this isn’t a sure thing. Parents with large families can sometimes have smaller offspring, and the reverse is true.

   2. Nutrition

Dogs fed with poor diets might not be able to get all the protein and minerals they need to develop into large, strapping dogs.

To maximize your puppy’s potential (and generally ensure that it’s well), you’ll need to provide it with a premium diet specifically designed for puppies.

These foods are higher in protein levels and are designed to give puppies the nutrients their bodies need.

If you have an adult dog of a large breed, it is important to choose an appropriate food specifically designed for their size. Large puppies that develop too fast may be prone to orthopedic issues later on in their lives.

How Does Spaying or Neutering Affect Puppy Growth Rate?

There are numerous misconceptions and myths regarding the implications of spaying or neutering, and many pet owners believe that their pet will shrink faster or won’t get as big when they change their pet.

The science behind spaying and neutering can create small changes in the development trajectory of puppies (pack an early lunch prior to visiting this link) and could affect the size of the adult dog in a very small way.

However, this shift in adult size happens at a different angle than most owners believe: Dogs altered before 16 weeks of age actually increase in size slightly larger compared to dogs who haven’t been spayed or naturalized.

But, hormones aren’t the main drivers of growth, but genes and nutrition are.

The distinctions that are triggered through the neutering and spaying treatments only come to light when you take a look at huge amounts of data that represent thousands of animals.

The decision to neuter or spay your dog shouldn’t alter the size of his adult in any significant way. You’ll need to learn more about the advantages and disadvantages of neutering and spaying your pet to better understand the time to get your pet sterilized.

The Adult-Sized Puppy Phenomenon

Be aware that some large breeds remain in the mental and emotional boundaries of puppyhood for a long time after they’ve been able to stop growing.

They might have grown to their full size and even passed their 2nd birthday, but they still have that adorable puppy look. Some also keep fun and playful attitude even now.

It’s not entirely clear what causes this to happen, but it could be related to social influences.

Puppy dogs display many of the same facial traits similar to other animals of the same age, such as big eyes and round faces, among others. They are believed to promote acceptance and caring behavior in adults.

Also, their puppy-like traits could help to prevent adult dogs from being averse to their unsocial behavior.

Puppy Growth FAQs

At what point is a dog mature?

Small breeds typically slow down growth between 6 and 8 months old. Medium breed puppies typically attain adult size by approximately 12 months. Large breed dogs typically stop growing between 12 and 18 months.

Do you know how big the puppy will grow?

You can estimate how big an infant will grow by analyzing the anticipated adult size for the breed. Paws may also give clues about the size of a puppy that it will be. Paws that are large on the puppy are typically an indication that the puppy will eventually grow into a bigger dog. The best method to gauge the size of your puppy’s growth is to take a genetic test for your dog!

How much can a dog develop after six months?

The rate at which your dog’s growth will accelerate after 6 months will mostly depend on its breed and the expected size of an adult. Dogs of smaller breeds will be near their entire size at 6 months. However, larger breeds will weigh around 2/3 or more of the adult size. The giant breeds will weigh approximately half of their adult size.

Tell us about the progress of your pet in the comments section below!