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

When Do Dogs Stop Growing

Puppies, just like human babies, grow up so fast. One day, they are like tiny fluffy balls of cuteness, and the next day, you’ll just wake up from what seems to be a short nap and they’ve already grown three or four times their puppy size.

But, when will they fully reach their mature size? When do dogs stop growing?

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.

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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.

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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.

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.

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Factors That Affect How Slow or Fast Can Dogs Grow

As mentioned earlier, a dog’s breed plays an important role in its growth rate. Aside from this, below are two other major factors that can affect how fast or slow a dog grows until he reaches his full size:


While your pup’s breed is part of his genetics, there are still more things to consider that fall under this category.

For instance, a dog’s blood line or the sizes of a dog’s parents are two factors that can influence his growth rate. Meanwhile, it’s also not true that a puppy’s paws can determine his size as he matures.

Moreover, every dog has unique sets of genetic codes that can determine how fast or slow he will grow, and how big or small he can be once he reaches his full adult size.

While some genetic traits are obviously transferred from parents to their puppies, some are also developed as a result of DNA recombination.

This means that even a large breed puppy can grow to be a small adult dog, and large breeds can also produce small offspring. In other words, the size of the parents doesn’t always guarantee the size of their puppies, though, most of the time it does.

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Providing your puppy with age-appropriate pet food is important as this is specially made to meet the vitamins, minerals, proteins, and other essential nutrients that he needs at his age.

Also, if you have large puppies, it’s crucial to provide them with puppy food that is designed for them.

Additionally, you don’t want to overfeed your puppy and to provide him with dog food that contains too much nutrients that he doesn’t need and his body cannot handle.

Also, large puppies that grow faster than their age are more vulnerable to suffer from orthopedic problems as they get older.

And if you don’t want to transition your pooch from puppy food to adult food, you can give him a specially formulated diet for dogs of all ages.

Simply check out the label of the dry or wet dog food, and look for the part that says “all life stages.” These are foods that meet the nutritional guidelines set by the Association of American Feed Control Officials (AAFCO).

Most importantly, make sure to always follow the feeding guidelines for such dog food to prevent under or overfeeding your pup. Obesity in puppies can predispose them to orthopedic issues later in life, such as hip dysplasia.

Hence, ensuring that your puppy’s health is in prime condition won’t only be good for his growth, but can also spare him of potential health issues later in life.

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Does Spaying or Neutering Affect Your Dog’s Growth Rate?

Technically speaking, spaying or neutering your puppy may only have a negligible effect on your dog’s growth rate. Based on data gathered, dogs that are spayed or neutered by four months of age grow a bit bigger than those that are fixed at a later time.

Nevertheless, your dog’s growth rate shouldn’t be the major factor that you should consider as to when you’ll have him fixed.

It’s still best to consult your doctor about the best time to do the surgical procedure. Also, hormones are not the primary movers of physical growth in puppies – genetics and nutrition are.

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 18th 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.

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