When Does My Puppy Stop Growing? — The Goody Pet
Everything You Ever Wanted To Know About Puppies & Growing

Everything You Ever Wanted To Know About Puppies & Growing

PETE DECKER / NOVEMBER 28, 2018 / DOGS

Almost everyone that ever had to take care for a puppy had wished that it stay like that forever - a super cute pup. But the nature of things says that every puppy is entitled to grow into a mature dog. Knowing that many people wonder when their pup will reach its full size. That’s especially emphasized when it’s a mixed breed.

What follows is a science-backed explanation of how puppies grow, growing different breeds, what affects dog growth rate, and at what age the process of growing stops.

All explained and detailed so that every dog owner can understand the process and apply the lessons in how they care about their dogs.

1

When Do Puppies Stop Growing?

Not all dogs stop growing the same age. That much depends on the size of the dog. Generally speaking, the bigger the dog, the more time it needs to reach its full size, and vice versa, smaller dog reach maturity much sooner.

Small Breeds

Chihuahuas are the typical representative of the small dog breeds. They need ten to twelve months to reach their full size.

Small To Medium Breeds

Miniature Schnauzers, Beagles, and Toy Poodles fall in the category of small to medium dog breeds. Typically, they are done growing by their 15th month and need two or three additional months to reach their full weight.

Medium To Large Breeds

Typical representatives to this category of dogs are the Boxers, Labrador Retrievers, and the Collies. They need around 18 months to stop growing and additional six to reach their full weight.

Giant Breeds

The Mastiffs and the Great Danes are typical representatives of this class of dogs. The growing process for them stops when they are three years old. However, they are pretty much grown when they are a year and a half old.

When it comes to giant breeds, it is their paws that reveal whether they are fully grown. When they are just small pups, their paws look more significant than what you'd expect them too, disproportional to their other parts. Once they are fully grown into their paws, they will look like they should, well-proportioned to the rest of their body. That’s how you tell if a big dog has grown in its full size or it got more growth ahead.

2

Why Do Some Dogs Grow Faster Than Others?

As mentioned earlier, small breed dogs stop growing much sooner than larger breed dogs. For example, when Chihuahua puppies are born, they weigh around 5 ounces. When they reach maturity, they weigh 5 pounds or so. Mathematically speaking, they increased their overall size for a factor of fifteen.

For comparison, when a Great Dane puppy is born, it weighs around one pound and reaches some 100 pounds and more than that, at maturity. That translates into a factor of a hundred. It only takes much longer to convert food into new tissue. That is why larger breeds need more time to reach maturity as opposed to their smaller counterparts that need much less time.

On average, smaller dogs stop growing when they are six to eight months old, while for larger breeds that period can vary from one year to eighteen months.

3

Factors That Can Affect Growth Rate

The dog's breed might be a significant factor that determines a dog’s growth rate, but some additional factors impact as well. The next two most significant factors are the dog’s genetic code and nutrition.

Genetic Code Differences

Each dog has its particular genetic code that has a significant impact over its growth period. Some genetics are inherited from parent to the puppy, while others are a consequence of a random variation that happens during a process called DNA recombination.

Nutrition

If a puppy doesn’t get all its proteins and minerals from its food than the pace of its growth can be strongly affected, along with its overall health. Therefore, it's important to keep it on a diet that contains at least the necessary minerals and proteins for healthy development. Other than that, the pup may grow at a much slower pace than what is typically expected or in some cases will never get to grow into its normal range.

Neutering Or Spraying

It’s a common misconception that spaying or neutering can affect the pup’s growth. There are those that believe it will alter the growth process to that extent that the pup won’t grow as large as it supposed to.  

Speaking strictly technically, neutering and spaying do trigger a slight and very subtle change in the pup's growth rate. And yes, there is a specific effect on the adult size of the dog. However, note the terms "slight" and "subtle". Meaning, the chances are so subtle, they are virtually unidentifiable.

Dogs altered before their sixteenth week get to grow slightly bigger than those that are not neutered or spayed.

Nevertheless, the point is that hormones are not what primarily drives growth - dog’s genes and nutrition are. The only way to see the difference between pups that have been neutered or spayed, with those that haven’t been, is only through tons of data spread in charts and tables, featuring hundreds or thousands of cases.

To that end, it is fair to conclude that the decision to neuter or spay your pet will not remarkably affect its growth.

Final Thoughts


The smaller the dog the sooner it will grow mature, and vice versa. There is no way to influence that. Also, there is no way to influence its genetics. That's given from its parents. The only thing that one can influence, concerning growth rate and how big it will grow is nutrition.

Therefore, feed it properly and love it unconditionally. That’s a proven recipe for growing a pup into an awesome dog.