When Do Dogs Stop Growing? What Are the Factors That Affect Their Growth?

Puppies are uber adorable – there is no question about that. But as expected, they grow in a matter of weeks. One minute they are just as big as your palm, the next thing you know, they have already outgrown their dog bed. And so you wonder, when do dogs stop growing?

Puppies sleep a lot, typically ranging from 16 to 20 hours a day. Their high need for sleep is essential for their growth and development. They are full of energy when awake, but their bodies and brains are still maturing, so they require ample rest to recharge.

As they age, they gradually sleep less and become more active during the day. It's important to provide a comfortable and safe sleeping environment for them to ensure their well-being and proper development.

Knowing when a dog stops growing has its advantages. For one thing, dog owners can finally pick the right crate, collar, or bed size for their pup once they know their dog is fully grown. Besides that, this knowledge can help pet parents gauge if their puppies are growing at a healthy and normal pace. 

So, if you’re among the many fur parents who've been curious about your dog's growth spurts, and when they will stop, read on. Although puppies grow at different rates, estimating when a dog will stop growing is possible based on various factors – all of which we will discuss in detail below. 

When Do Dogs Stop Growing?

As a dog parent, it’s such a rewarding experience to be part of your growing puppy’s life and to see him grow and reach his adult size eventually. And as to when that will be, there’s really no single answer that applies to all breeds and sizes of dogs.

Some puppies persist to grow up to two years, while some may reach their full size and full adult weight between 10 to 12 months.

Several factors affect the length of time before a puppy’s adult size is reached. However, for most dogs, it could come anytime between 6 and 8 months of age. 

Generally, larger breeds such Mastiffs, and Labrador Retrievers take more time to grow than smaller breeds like Toy Poodles and Chihuahuas. And this is because larger bones and joints need more calcium to grow and develop.

However, this mineral can’t build up inside a dog’s body that easily. Hence, apart from good nutrition, you also need stocks of patience before you can see your German Shepherds or other larger breed dogs reach their full glory.

How Do Puppies Grow?

As far as height is concerned, a puppy’s legs grow pretty much the same way as human legs do. And such growth is primarily influenced by two distinct places in the long bones called the growth plates.

Also, while soft tissues and muscles grow all throughout a dog’s life, bones do not. And that’s why there comes a time when puppies stop growing already.

This is also the time, when the increase in size will just manifest horizontally, and not vertically. Or to better understand the concept, this is the time when we, humans stop to grow taller. Instead, we expand or become bulkier or fatter because we only gain muscle mass or fats.

Again, it’s also the same way with our canine companions. Their muscles can grow with diet and resistance training, but when they reach adulthood, their bones will stop to grow, as well.

Why do dogs and humans stop growing vertically at a certain age?

As mentioned earlier, this is because of the growth plates. These are thin cartilaginous areas where new tissues are produced, and they are located at each end of the long bones.

At a young age when the new tissues are still being formed, humans and canines have soft and flexible growth plates.

However, as puppies age and go nearer towards becoming adult dogs, the soft tissues in the growth plates start to harden, calcify, and stop producing new tissues.

When this happens, the soft tissues become bones, and the growth plates are considered to be closed. And this only means that the long bones cease growing already. This is the time when a dog is said to have finally reached its full adult size.

Again, even if the bones are fully developed and your dog stops growing, he will still continue to develop fat and muscle, just as we, humans do.

Growth Signs In Puppies

Besides an increase in size, physical growth can be observed in three other parts of your dog’s body. Bear in mind, though, that these wouldn’t determine final size of a dog or when it will stop growing.

Teeth. You can easily differentiate a puppy from adult dogs by taking a look at their teeth. Teething usually starts at around 2-4 weeks and all 28 baby teeth should come out when your puppy is around 5 to 6 weeks. When your dog turns 6 months or more, all baby teeth would have fallen out and be replaced with permanent or adult dog teeth.

Ears. Puppies of all kinds, regardless of breed, are born with cute, droopy ears with the ear canals closed shut. As they grow, their ears grow to adjust to the size of its body.

Paws. Like the ears, a dog’s paws also increase in size, especially when they’re around 4-6 months of age. But, as always, the size of their paws will depend on their breed.

Can Exercise Support Your Puppy’s Growth?

Growth plates are fragile regions in the bones. And as mentioned earlier, these are the parts where new soft tissues grow. This being said, it is important to prevent injury and damage to these areas.

Hence, you should not let your growing puppies endure strenuous exercises, or even prolonged and excessive physical activity like jogging as these can be extremely detrimental to their growing, and fragile joints and bones.

It’s also important not to let your puppy jump at great heights, such as from the floor up into your bed or couch.

Limiting physical activities to prevent injury of the frail growth plates is applicable to all breed size, from small toy breeds like Toy Poodles to giant breeds like Great Danes.

To use up your puppy’s energy, you can walk short distances with him moderately until the growth plates have fully fused or until your dog has finally stopped growing.

5 Factors That Affect Puppy Growth

As mentioned, dogs grow at different rates. And much like humans, your dog’s size is largely determined by genetics and secondly by external factors or the environment.

Genetics

Your puppy’s growth rate is largely dependent on genetics. So if you’re wondering how big your dog is, the best way to gauge your dog’s future full-grown size is by checking the previous litter of your dog’s parents.

That’s right. Because at the end of the day, your puppy’s appearance and size are determined by how small or big its parents are. Enter: Breed size and breed purity. 

Breed Size

In the doggo kingdom, dogs are classified into 4 categories based on size. Smaller breeds tend to reach their full adult size in a shorter amount of time compared to large-breed dogs. And this makes sense. Big dogs like the Great Dane will require more time to grow and develop since they have bigger bones.

American Kennel Club also has a puppy growth chart that’s worth checking out. However, if you want to have an idea about the normal growth rate of small dogs compared to larger dogs, see below. 

Small Breed Dogs (20 lbs and less)

Given their tiny size, a small dog like the Shih Tzu and other small breeds usually double their size when they are about 4 to 6 months of age. They stop growing when they’re around 10 to 12 months old. On the other hand, toy dogs will most likely reach their adult size earlier than other small breeds.

Medium-Sized Dogs (21 to 50 lbs)

As expected, medium-breed puppies like the Dalmatian and Collie take a bit longer to grow than a small-breed dog. Often, these types of dogs experience rapid growth when they’re around 8-12 weeks. Full size is reached when they’re around 12 to 15 months of age.

Large Breeds (51 to 100 lbs)

Large breed puppies (like the German Shepherd) typically double in size at around 8 to 12 weeks and reach their full size when they turn 18 months old. 

XL or Giant Breeds (100+ lbs)

A giant breed like the Great Dane takes a longer time to mature. Giant breed puppies usually take 18 to 24 months of age to reach their maximum height.

Breed Purity

Purebred dogs are more predictable than mixed-breed dogs. As such, it's easier to guess when purebred puppies will stop growing compared to mixed-breed dogs. 

Based on the breed, you already know what to expect from purebred puppies – from their temperament down to their size. On the other hand, determining when a mixed breed will stop growing is going to be tricky, especially if their lineage is unknown. 

However, if you do know the breed or the size of the parents, you can at least guess how big your puppy will get by getting the average of the parents' weight or size.

Gender

Compared to female dogs, male dogs are often taller and larger. Male dogs also take longer to grow than their female counterparts.

Nutrition

Growing puppies (whether small or large puppies) require proper nutrition to achieve optimal health and development. As such, it’s best to give puppies pet food specifically formulated for their life stage and breed. Doing otherwise can lead to stunted growth.

Unlike adult dogs, a growing puppy requires food high in energy and protein. Besides that, your dog’s breed also matters. Compared to small dogs, a giant or a large breed puppy requires a diet with less calcium for their bones to develop properly. 

Although larger breeds have a lot of growing to do, these large dogs can’t grow up too fast. Growing too quickly for large dogs can result in skeletal abnormalities. This includes bow-leggedness and panosteitis.

Neutering or Spaying

According to PetMD, puppy growth can also be affected if you neuter or spay your dog too early. However, instead of stunting its growth, it does the opposite. 

A puppy that’s neutered or spayed before it sexually matures usually grows taller. This, later on, leads to joint problems. As such, AKC recommends neutering or spaying your puppy once it reaches sexual maturity or is fully grown.

Underlying Health Condition

A puppy with worms (whether it’s roundworms or hookworms) may not also reach optimal growth since the worms eat up the calories that your dog needs to grow. Getting this removed, though, can get your dog back on track growth-wise.

Average Ages When Adult Dogs Reach Their Mature Size

Different breeds and dogs of varying sizes reach their mature size at a different rate and time. Generally, small breeds will reach their full size sooner than larger dogs.

Nonetheless, below are the different timelines for the maturation of small dogs, medium size puppies, and larger dogs.

Small Breed Dogs

Small breeds typically have growth spurts at 4 to 6 months of age and reach their mature size between 10 and 12 months. Examples of small breed dogs are Chihuahuas, Dachshunds, Bichon Frise, and Yorkshire Terriers. These dogs are usually less than 25 pounds when fully grown.

Medium Sized Dogs

Medium breeds are dogs that are around 25-50 pounds once they reach their mature size. They are also expected to double their puppy size between 8 to 12 weeks and reach their full size between 12 to 15 months. Examples of medium-sized breeds are Beagles, Miniature Schnauzers, and Basset Hounds.

Large Breed Dogs

Large dogs are dogs that weigh over 50 pounds when they reach their full size, and these include big dogs such as Pit Bulls, German Shepherds, Labrador Retrievers, Boxers, and Collies.

These dogs also double their size once they reach 8 to 12 weeks, and they become full-grown adults at their 18^th month.

Giant Breed Dogs

Giant breed dogs are obviously the tallest, but they also take the longest time to reach their fully-grown size, which usually happens when they are around 18 to 24 months of age. They’d even have to wait up to three years before they can fully reach their mature weight.

Tips To Encourage Growth In Puppies

Stunting your dog’s growth is never a good idea. The same goes if you decide to speed up the process. So what can you do to encourage a healthy and normal growth rate in puppies? 

Although we can’t do anything about your dog’s genes, we can do something about what they eat and their environment. Here are 4 things you can do to help your puppy grow.

• Give your dog high-quality, AAFCO-approved dog food and keep them hydrated. Obesity can also be avoided if you follow the feeding guidelines mentioned on the label.

• Schedule playtime each day. Besides giving your dog the exercise it needs to improve your dog’s overall health, this will also strengthen the bond between you and your pup. Note, though, that you shouldn’t tire your puppy so much. Jogging outdoors with your pup on hard surfaces like concrete is something you can wait to do until your dog is fully grown.

• Give your pup toys. Giving your dog toys like a puzzle, chew, and tug toys will keep them mentally and physically active during those times of the day when you can’t play with them.

• Visit your vet regularly. A puppy’s first year is crucial in a dog’s life. This is why a vet visit is needed once your puppy turns 6 weeks old. And it doesn’t stop there. Your pup will require regular wellness check-ups every 3-4 weeks until they’re around 16 weeks old. 

Aside from getting the needed vaccinations, your vet can also provide veterinary advice regarding your dog’s nutrition, growth, and overall development. 

Conclusion

Dogs grow at different rates. As such, finding out when a dog will stop growing can be tricky. One thing is for sure, though. Large breeds take longer to grow than smaller breeds. In fact, it takes a large breed twice as long to develop and grow. 

Regardless of breed, your pup’s growth rate should be kept at a normal pace – not too fast and not too slow. More importantly, you need to provide your puppies with loads of TLC. This way, your dogs will not only achieve optimal physical growth, but they will also be mentally and emotionally healthy – all of which are important to improve your dog’s quality of life.