When Will My Puppy Stop Growing?

Kelly Roper
Chihuahua and Great Dane

When do puppies stop growing? That's something many owners would like to know. However, this is a question that has more than one answer.

Dispelling a Generalization

It used to be considered common wisdom that dogs stop growing once they reach one year of age. While that may be a fairly accurate statement in some cases, it does not hold true in others.

This misconception is largely due to the fact that many kibble manufacturers recommend that you only feed puppy kibble until your dog reaches one year of age. However, a puppy does not magically stop growing on the day of its first birthday.

Growth Rates Differ by Breed and Size

If you make a comparison using breeds at both ends of the spectrum, it becomes apparent that all breeds do not grow at the same rate.

For example, compare the Chihuahua and the Great Dane. The Chihuahua will remain relatively small throughout its lifetime, and it doesn't have nearly as far to grow to reach it's adult size as a Great Dane puppy does. So, the Chihuahua will likely reach its adult frame and rate closer to one year of age, while the Great Dane will take much longer to fully mature in size.

So, When Do Puppies Stop Growing?

Although nutrition and living circumstances play a definite role in when puppies stop growing, each puppy is an individual and may grow at a slightly different rate than other members of its breed or even from its own litter. Still, a few generalizations can be applied to dogs that fall into basic size categories of small, medium and large breeds.

Small Dogs

Most small dogs will reach their full body frame size by approximately one year of age.

For example, the smallest breeds, such as Chihuahuas and Yorkshire Terriers will likely reach their ideal adult weight by age one. However, stockier breeds such as the Chinese Pug and Shih Tzu may take a couple of months beyond that for their weight to catch up to their frame size.

Medium Dogs

In general, most medium size breeds will reach their full adult frame size between 12 and 15 months old. Breeds with stockier bodies may take as long as 18 months of age for their weight to catch up to their frame size.

Compare the frame size of a Whippet to a Clumber Spaniel. Both are considered medium-sized breeds, but their body types represent opposite ends of that spectrum. So, the Whippet will most likely stop growing sooner than the the Clumber Spaniel.

Large Dogs

Large breeds take the longest of all to reach their full size. Their frames typically keep growing until they are between 18 months and 24 months of age, while they may be anywhere from 24 to 36 months old before they reach their full adult body weight.

For example, an Irish Wolfhound has a large frame, but its body is actually rather lean. By comparison, a Mastiff has a large frame, but it also has a lot more body density and musculature to go along with it. So, the Wolfhound will likely reach full maturity quicker than the Mastiff.

Expectations for Your Own Puppy

As you can see, it's difficult to pinpoint an exact answer to the question "When do puppies stop growing?" The best you can do is compare your own puppy's expected size, based on his breed heritage, to the examples given above. Watch him carefully as he nears adulthood, and you'll eventually notice that he hasn't grown any larger for several months. At that point, it's safe to assume he has finally stopped growing.

When Will My Puppy Stop Growing?