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When Do Puppies Stop Growing?

4 min read

Updated - Jun 14th, 2022

New puppies are little balls of energy that bring joy and fun to your family. However, they can grow incredibly fast, causing their needs to change in the blink of an eye. As you try to keep up with their physical development and emerging behaviors, you might be wondering, “When do puppies stop growing?” 

Here, we’ll give you an overview of what to expect as your puppy grows. By understanding each phase of development, you’ll be able to better support your puppy as they discover themselves and the world around them.

When do dogs stop growing? 

Puppies grow the most during their first eight weeks of life. Afterward, their development slows down but can continue until they’re about six to 24 months of age. Generally, smaller dog breeds reach maturity faster than larger dog breeds, as larger dogs may need more time to grow and develop their bones. Female dogs also tend to mature faster than male dogs. However, other factors determine how quickly they reach each stage of maturity, such as genetics and health conditions. 

Beginning from birth, growing puppies go through the following growth stages:

  • Neonatal period (0-2 weeks): The neonatal period is when puppies is the period right after a puppy is born. They are fully dependent on their mothers to survive and have very limited senses. 
  • Transitional period (2-4 weeks): Puppies begin to open their eyes, grow their teeth, and continue to develop their senses. They interact with other puppies in their litter.
  • Socialization period (3-12 weeks): The puppy socialization period largely determines a puppy’s personality. They become more acquainted with their surroundings and learn how to socialize with other animals. 
  • Juvenile/testing period (3-6 months): At the juvenile or testing period, dogs explore their world with more curiosity. They exhibit various behaviors like puppy biting and teething as they test their boundaries and explore their fears. 
  • Adolescence (+6 months): At adolescence, your puppy becomes the equivalent of a teenager and begins to experience puberty. It is highly recommended that pet owners train their puppies and reinforce healthy socialization skills at this stage of growth.

Toy dog breeds (Less than 15 pounds)

Because toy-sized dog breeds are the smallest, they mature the fastest. They typically reach their adult size at around six to eight months, and reach physical and sexual maturity by their first year. Some common toy dog breeds are the:

Small dog breeds (16-25 pounds)

It can take about eight to 12 months before a small dog is done growing. Some examples of small dog breeds are the:

Medium dog breeds (26-55 pounds)

Similar to small breeds, medium breeds can also take eight to 12 months to finish growing. The following are considered a medium-sized dog: 

Large dog breeds (55-100 pounds)

Large breeds take roughly 10 to 16 months to reach their full size. Some large dogs may take a longer time depending on their size, but their dog food may play a significant role in shortening or lengthening their puppyhood. Some large breed dogs include the: 

Giant dog breeds (More than 100 pounds)

Due to their enormous size, giant breeds can take the longest to reach full maturity. It can take 10-18 months for them to finish growing, with some even taking 20 months. Giant breeds have different dietary requirements than small breeds. Pet owners should make more frequent visits to the vet to ensure that their nutritional needs are being met. 

A few examples of giant breeds consist of the: 

Factors that affect puppy growth 

Aside from genetic factors, there are other circumstances that directly influence your puppy’s growth. If they aren’t fed the right type of puppy food or are nutritionally deficient, they can stop growing at a normal rate. However, when it comes to feeding larger breeds, pet parents may actually need to make sure they’re not growing too quickly. Excessive calcium in a large breed puppy’s diet can negatively affect their bone development. When purchasing dog food, check that it is formulated for your dog’s breed and size so that they receive the nutrition they need. 

Another factor that can affect puppy growth is an illness like roundworm or hookworms, which are parasites that live in their digestive system. These worms can stunt your puppy’s growth until you treat them with prescribed medication and proper care. Your precious pooch deserves the best protection – as a young puppy and beyond. That’s why Pumpkin Pet Insurance plans help pay 90% cashback on eligible vet bills, so you can give them the best care possible.

Shi-won is a copywriter and an enthusiastic dog aunt to Maltese and Shih Tzu puppies.