When Are Shih Tzu Fully Grown?

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Bred as companion dogs, Shih Tzus come from an aristocratic lineage, having graced the laps of Chinese noblemen for over 1000 years. Their luxuriant coat, tiny stature, and beautiful eyes set them apart from other dog breeds. Apart from a few genetic issues, the Shih Tzu is generally a healthy dog.

The Shih Tzu is a gentle breed that is friendly and good with children. Their easy-going nature and limited exercise requirement make them excellent apartment dogs. Although they are entertaining to be around, they also have a stubborn streak that you should ideally tackle early in their development.

Continue reading to find out more about their growth, developmental stages, and when are Shih Tzu fully grown?

When Are Shih Tzu Fully Grown?

Shih Tzu—Developmental Stages

As the Shih Tzu is a toy breed, its transition from a newborn to a full-grown adult dog is quite fast.

But how do you determine whether your puppy is a newborn, a puppy, or an adult?

When is a Shih Tzu full-grown?

Read on to find everything you need to know about the growth of your Shih Tzu.

If you are a new Shih Tzu owner, you may find your dog’s growth rate overwhelming and wonder when it will stop growing. But don’t worry, it won’t grow too huge!

Shih is a toy breed and matures early, so although your puppy seems to be growing very fast, it will soon reach adulthood and attain complete growth.

A Shih Tzu goes through several stages of development on its way to adulthood. Once they’ve developed, we categorize them into adult or senior dogs.


Shih Tzu puppy
Shih Tzu puppy

A Shih Tzu is considered a newborn from birth to three weeks of age. Right after birth, touch, taste, and smell are the only developed senses.

Their eyelids are completely closed, and they cannot hear as the ear canals are also closed.

The newborn cries or whines to communicate any feelings of pain or discomfort. Their body temperature is much lower than that of an adult dog, so they need an external source of warmth.

Shih Tzu newborn puppies cannot urinate or defecate on their own and need their mother’s assistance in stimulating the processes.

By the end of the newborn stage, the puppies start developing their sense of sight and hearing. They start crawling and even vocalizing with peeps and squeaks.

Young Puppy

Spanning from 4 weeks to 4 months, this developmental stage marks significant milestones in the puppy’s development.

Between 3 and 6 weeks, the puppy starts recognizing its mother, plays with its littermates, begins teething, and is ready to be weaned.

By six weeks, you will start seeing the typical Shih Tzu characteristics, the emergence of fears, and a peak in curiosity evident from their ventures around the house.

At around three months, the puppy experiences a growth spurt. During this time, the Shih Tzu puppy develops quickly, so you will need to feed it a nutritious puppy diet. By this stage, your pup will need three scheduled meals and snacks.

Older Puppy

Shih Tzus are categorized as older puppies between the ages of 5 and 11 months. They have reached all of their development milestones at this point, marking the final stage of development. As the growth rate decreases, you can reduce feeding portions.

At this stage, teething is almost over. The super-hyper puppies transform into their calmer versions and understand commands. The start of this phase coincides with the adolescent stage, and many Shih Tzu females may experience their first heat.

Most puppies attain their full weight by eight months of age; however, some may continue growing up until 15 months.

Adult Dogs

adult shih tzu
adult shih tzu

Shih Tzus are considered adults when they reach full maturity at 11 months of age. During this time, the Shih Tzu is in its prime years.

Displaying all things Shih Tzu, the dog is fun to be around. It follows the owner around the house, joyfully adjusting to every available lap, and is a little clingy.

Senior Dogs

When Shih Tzus have reached 10 years or older, they are called senior dogs. Some dogs may develop hereditary and age-related diseases during this stage.

Shih Tzu Size Chart

Shih Tzus exhibit rapid growth and development. Thus, it is important to monitor the dog’s weight at regular intervals to identify any underlying health issues.

A Shih Tzu reaches full maturity between 6 and 8 months, standing 9 to 11 inches tall and weighing 7 to 12 pounds.

To determine the ideal puppy weight at every stage, refer to the size chart below:

Age Of The PuppyEstimated Weight (in pounds)
newborn Less than 1 pound
1 monthApproximately 10% of adult body weight – around 1.25 pounds
2 monthsApproximately 20% of adult body weight- between 2 and 2.25 pounds
3 monthsApproximately ⅓ of adult weight – 4 pounds
4 monthsApproximately ½ of adult weight – 6 pounds
5 monthsApproximately ⅔ of adult weight – 8 pounds
6 monthsApproximately 83% of adult weight- 10 pounds
7 monthsApproximately 96% of adult weight- 12 pounds
8 monthsApproximately 100% of body weight-12.5 pounds
12 monthsApproximately 12.5 pounds
Shih Tzu Size Chart

The above chart gives a rough estimate, and although most dogs attain their full weight by 8 months of age, some may continue to grow up to 2 years.

Their weight at 8 weeks can also be used as an indicator of the dog’s weight at full maturity. So, a dog weighing less than 2 pounds at 8 weeks usually turns out to be a small Shih Tzu dog. And puppies weighing 3.25 and more at 8 weeks develop into larger dogs.


A Shih Tzu dog is a small companion dog that matures within the first year of its life. As small dogs, their growth and development are relatively fast. Tracking parameters such as their height and weight can help identify any health issues that might arise.

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I am the owner of Shihtzuadvice.com and the proud parent of two black and one gold Shih Tzu's. I belive that the Shih Tzu is the best all-around dog for anyone and want to share with you as much valuable knowledge as possible about this great breed!

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