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When Do Dogs Stop Growing? A Puppy Growth Guide

Laura Day

July 23, 2019

When Do Dogs Stop Growing

When adopting a puppy, the first thing you need to know is how fast he will grow and how big he will be when he stops growing. This allows you to accommodate all of your pup’s needs throughout his life. For instance, knowing your puppy’s growth rate allows you to buy appropriately sized collars and leashes and helps you understand how much you should be feeding him. This is vital information that ensures that your furry friend has the best quality of life possible.

The growth rate of puppies depends mostly on the breed that they belong to. The time frame differs based on the size that they should be as fully-grown adult dogs. Because of this, you should look at each section of this handy guide based on whether your puppy is part of a small, medium, or large breed!

Basic Signs of Growth in Puppies

There are some similarities that all puppies face when growing. Keeping these in mind will help you recognize the growth in your own pup regardless of breed size.

Neonatal (Newborn-2 Weeks)

  • Puppies at this age will sleep most of the day, waking up mostly to nurse.
  • The birth weight will double within a week.

Transitional (2-4 Weeks)

  • A puppy in the transitional phase will begin to open its eyes and learn to walk.
  • The pup will begin to grow his baby teeth.

Juvenile (4-12 Weeks)

  • The juvenile period precedes puberty and sexual maturity. At this time, your pup will begin to play and run more, strengthening his muscles.
  • During this stage in a puppy’s life, he will begin to grow rapidly. You may notice these changes every day.
  • Sometimes, puppies at this age get more aggressive and fearful of others. If you notice this happening, it is a normal part of growth.

Adolescence (6-12 Months)

Dogs Stop Growing

  • Female puppies may begin to go into heat at this age. Male dogs will be more interested in sex.
  • Physical growth will slow down at the end of this period.
  • The baby fur begins to be replaced by their adult coat.

Full Maturity (1-2 Years)

  • After adolescence, your pup will become a dog. They will stop growing bigger, though they can still gain muscle over time.

Something to keep in mind–the growth of purebred puppies may differ a bit from mixed breeds. It depends on the breed and size of both parents in most cases. This just gives you a general idea of the stages you should be aware of.

Now that you know what to expect in almost all dogs, you can go more in-depth to exactly what your pupper may experience based on his size and breed.

Toy Breed Growth Guide

Toy puppies are the smallest of all, and they will likely reach full physical and sexual maturity earliest. These are:

  • Toy Poodle
  • English Toy Spaniel
  • Japanese Chin
  • Miniature Pinscher
  • Papillon
  • Pekingese
  • Toy Fox Terrier

How fast do toy dogs grow?

These toy puppies will likely reach full physical maturity just shy of a year.

Small Breed Growth Guide

Which breeds are considered “small?”

If your pup belongs to any of these breeds, he is considered as “small.” These are just some of the most common examples to give you a good idea of what you are working with:

  • Pug
  • Dachshund
  • Chihuahua
  • Maltese
  • French Bulldog
  • Pomeranian
  • Shih Tzu

How fast do small dogs grow?

If you have a small breed of dog, you can expect it to grow to full maturity within a year. Some stop growing in as little as 8 months! Sounds crazy, right? Well, it may not be as crazy as you think. The answer is pretty simple.

Small breeds stop growing more quickly because, of course, they do not have to grow as much! Any puppy will start out tiny, but a large breed puppy like a German Shepherd has a long way to go before he reaches his full size.

Medium Breed Growth Guide

Which breeds of dog are considered “medium?”

Australian Shepherd

A few examples of dogs that grow up to be medium-sized:

  • American Foxhound
  • Australian Shepherd
  • Basset Hound
  • Border Collie
  • Bull Terrier
  • Bulldog
  • Dalmatian

How fast do medium-sized dogs grow?

In medium-sized dogs, growth stops at around 18 months and they usually reach their final optimal weight at 2 years. These puppies stop growing about twice as slow as small pups.

However, they will grow at a faster rate than the smaller breeds within their first year and need to be closely monitored in order to ensure that they get the right diet for their needs.

Large Breed Growth Guide

Which breeds are considered “large?”

These breeds are commonly known to grow into large dogs at the end of their growth stage:

  • Akita
  • Bernese Mountain Dog
  • Boxer
  • Bullmastiff
  • German Shepherd
  • Greyhound
  • Golden Retriever

How fast do large dogs grow?

Puppies of large breeds usually reach full physical maturity at around the same time as medium-sized breeds, having a growth spurt between 8-14 months. At 18 months, they are considered to be entering the adult stage with some dogs growing to as much as 75 lbs.

Giant Breed Growth Guide

Which breeds are considered “giant?”

Some puppies will grow into giants, outclassing even the larger dogs you may have seen in the past. The pups are from these breeds:

  • Great Dane
  • Bernard
  • Great Pyrenees
  • Irish Wolfhound
  • Giant Schnauzer
  • Mastiff

How fast do giant dogs grow?

These dogs take the longest time to grow to full maturity, most reaching their adult stage at 3 years. They can weigh up to 150 lbs. easily without being considered overweight. Keep in mind that if you get puppies of any of these breeds, they need space to keep maturing comfortably. Be sure that you give your doggo a big backyard and a home big enough to walk around in.

By using this guide, you can learn when your puppy needs vet visits and a balanced diet as well as how big of an area you need to give him in order for him to be most comfortable and happy!


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