When Will Your American Bully Puppy Fill Out?

American Bully puppies grow rapidly. One moment they’re adorable little furballs; the next moment, they’re grown up and all over the place.

You can tell if your puppy dog is growing healthily by knowing when to expect them to fill out. American Bully pups fill out when they’re around 12 months old. Puppies of bigger

American Bully types will continue growing until they reach 18 to 24 months old. However, you should communicate with a vet to see the problem if your doggy isn’t growing as anticipated.

In this article, we’ll discuss the American Bully puppy’s growth cycle and what you can do to encourage healthy growth.

Importance of Understanding the Growth and Development of American Bully Puppies

You must understand the growth timeline and pattern of American Bully to know if your dog is growing accordingly or not. If your Bully is not growing by the scheduled time, some issues might arise.

The same is true if your Bully is growingly uncontrollably. By having a basic knowledge of the growth chart, you can avoid many health issues in your Bully, which could occur due to ignorance or other reasons.

This may also save you from concerns about their growth and why they have not filled out yet. Understanding the growth and development of your American Bully will also help in choosing their diet.

American Bully has a muscular body, so they need a protein-rich diet, especially as they grow up. In addition to this, they also need calcium to develop their bones.

American Bullies generally stop growing at 12 months of age. However, a bully can take longer or less time to fill out, depending on its size. Bigger American Bullies will continue increasing bone size and height, extending the growing time to twenty-four months.

Although there is an average projected size for each American Bully class, the actual size may vary because some bullies have a slightly larger physical frame than others.

As a result, the skeletal structure of your four-legged family member influences how tall they will get. The long bones in American Bully puppies’ legs develop at their soft growth plates.

The growth plates build new bone structures, frequently beginning gently before gradually stiffening as the pup develops. When the growth plates stop creating new tissue and become calcified, or “closed,” the bone has reached its full size.

Small breed puppies typically mature between 6 and 8 months of age, whereas medium and giant puppy breeds typically take longer.

Factors Affecting Growth and Development

The American Bully is inclined to several health complications like other dog breeds. Bully mix breeds may also develop the diseases listed.

The following are the most common health problems this breed faces:

1. Hip Dysplasia

Hip dysplasia is a deformity resulting from the hip joint evolving improperly and impairing the dog’s activity.

2. Patellar Luxation

This is a standard of the kneecap’s unusual development, which eventually dislocates and results in trudging and unbearable agony.

3. Cleft Lip

This condition represents a mouth or upper lip deformation.

4. Demodectic Mange

American Bullies don’t have a dense, double coat; demodectic mange is relatively simple to notice in these dogs. Hair loss and scabs are signs of this condition.

5. Hereditary Heart Failure

This condition, which is also known as an “enlarged heart,” results in an increase in bodily fluid.

6. Ichthyosis

This skin problem makes the dog’s paw pads thicker and more likely to skin.

7. Atopy

It should be treated to relieve discomfort because it is a common skin allergy. It frequently appears with distinctive coat colors, such as the blue Bully.

8. Cerebellar Abiotrophy

One of the unusual conditions that may be found in American Bullies is this one. The nervous system and the brain of the puppy are affected.

9. Hypothyroidism

This causes the dog to develop significant thyroid gland problems that influence its weight, increasing weight and restricting its activity.

10. Progressive Retinal Atrophy

PRA causes the dog’s vision to decline steadily and even results in blindness.

11. Cataracts

Another eye condition affects this breed. Eyesight loss is possible because of cataracts, although it can be treated surgically.

Any of the disorders mentioned above may impact the rate of the dog’s growth. You should see your vet for health tests if your puppy significantly exceeds the average American Bully growth chart.

American Bully Growth Chart?

Age: 3 months 6 months 1 year
Weight 20 – 35 lbs 50 – 70 lbs 55 – 75 lbs
Height: 8 – 10 inches 14 – 18 inches 16 – 20 inches

The chart above will clarify how big your American Bully might be at a certain age. But there are four classes of American Bullies that grow to be different in adulthood.

These categories include Standard, Classic, Pocket, and XL American Bully. Although they belong to the same breed, they are all different sizes and shapes.

Here are the general guidelines of American Bully by class:

Type of American Bully Male Size Female Size
Standard Bully Height: 17 to 20 Inches

Weight: 30 to 75 lbs

Height: 16 to 19 Inches

Weight: 25 to 65 lbs

Classic Bully Height: 17 to 20 Inches

Weight: 30 to 60 lbs

Height: 16 to 19 Inches

Weight: 25 to 60 lbs

XL Bully Height: 20 to 23 Inches

Weight: 74 to 130 lbs

Height: 19 to 22 Inches

Weight: 74 to 130 lbs

Pocket Bully Height:14 to 17 Inches

Weight: 20 to 50 lbs

Height:13 to 16 Inches

Weight: 20 to 45 lbs

One thing to note is that a Pocket American Bully will weigh significantly more compared to its height. All other classes weigh accordingly to their height.

When to Expect Your American Bully Puppy to Fill Out?

By filling out, we mean an adult dog to reach its full size and weight that it’s supposed to naturally. An American Bully will fill out at around 12 months.

However, some American Bullies may take longer or a little less time to become fully grown. Bigger American Bullies such as XL can keep growing for 24 months.

American Bully’s bones keep getting bigger at their soft growth plates. New bone tissues form in growth plates, starting softly before gradually hardening as the Bully grows.

The growth plates will halt creating new tissue and become calcified when the maximum bone size is reached. Even though they are considered adults at 12 months old, puppies resume growing.

Their size, height, and bone growth could take anywhere from 6 to 24 months to fill out. Larger dog breeds like the XL American Bully need about 24 months to reach adulthood.

An American Bully’s weight should always be balanced with its size; all varieties have no ideal weight. A standard American Bully weighs 66 to 88 pounds.

Remember that dogs of the same breed will grow at different rates; moreover, ensure your Bully gets the best nutrition and grows in a safe environment.


Your dog’s physical growth is sometimes on a different timeline than its mental growth. The process via which a dog’s head grows till it achieves its maximum size as it matures and transforms from a pup to an adult dog is called head splitting or cracking.

Despite what some owners may believe, the dog’s head doesn’t really “break” or “split.” The dog’s head will fluctuate a little in size and shape.

Some owners might not notice these changes when they happen because they are often sluggish and minute.

Since some dogs have thinner skulls than others, it may take longer for their muscles to mature and develop properly.

The head of American Bullies is one of their most unique characteristics; thus, it is easy to recognize their development by the size and growth of their heads.

At 9 months, an American Bully’s head begins to split, dilating until the dog is 12 to 18 months old. You might not even detect the differences as they take place because they will be slow and incremental at this point.

By the time it is 12 months old, the American Bully should start gaining adult height and weight. However, it is common for certain breeds to take longer than that, frequently up to 2 or 3 years.

Average Time Frame

In the following sections, I will describe how to tell if your Bully puppy is growing sufficiently for its growth stage.

American Bully Younger Than a Month

American Bully puppies are at their most fragile stage of development. These puppies are still developing and rely entirely on their mother for heat and nourishment.

They will consume and nap for the majority of the daytime and nighttime. They must be dewormed as soon as feasible because they are prone to contracting worms at this age.

A Month-Old American Bully

Your American Bully puppy will open his eyes now, and his ears will start working. Besides, he will begin consuming regular meals after his milk teeth emerge. As he interacts with his siblings, his tail will shortly waggle. To evade eventual social problems, your pup should associate with people.

2 Months Old American Bully

Before they turn 2 months old, American Bully pups grow fast, and they are now at the period when they can get their first shots at the vet and discover their permanent house with their new owners.

At this point, your puppy is also memorizing social talents and how to interact with different people and their environments.

An 11-Week-Old American Bully

Although your American Bully pup will be active at eleven weeks old, don’t overwork it. Its growth plates will be too frail to support sustained activity, and its joints will still be delicate.

A 3-Months-Old American Bully

Your American Bully puppy reaches youth at 12 weeks or three months old.

His growth will slow down from this point on, and his senses should be completely developed.

They need regular socialization and education at this age but should practice tolerance because they have poor attention spans.

A 4-Month-Old American Bully

Your American Bully is a teenager at four months old and is ready to challenge the limits. He is trying to determine his capabilities and boundaries.

At this point, puppy training can support good manners and prevent the establishment of bad ones. Spend a minimum of 20 minutes per day training your dog.

A 6-Month-Old American Bully

Your Bully puppy will reach sexual maturity at six months, and females may go into heat for the first time.

Although male dogs usually grow sexually faster than female dogs, you shouldn’t breed them at this age because they are still considered pups.

Behavioral issues, such as wrath and rebelliousness, may become evident at this age. Additionally, your American Bully picks and chooses who it deems to be buddies as it ages.

Aggression towards other dogs and strangers may occur if your American Bully needs to be comprehensively socialized and trained.

A Year-Old American Bully

Your American Bully will already mature to adult size and weight by this age. It will soon be capable of transitioning from little puppy food to adult food, requiring a lot of exercise to prevent diseases like obesity and diabetes.

During this stage, your dog’s growth plates start to harden and close. It won’t change much as it ages, but its muscles are defined more as it gains weight.

Variation Among Individual Puppies

American Bullies are classified as a small-to-large breed in terms of size. They are bigger, stronger, and have broader skulls than their ancestors. American Bullies are classified into four types according to size.

1. Standard American Bully

Male Standard Bullies are typically 17 to 20 inches tall, but female Bullies are typically 16 to 19 inches tall. Weight differences between men and women range from 60 to 80 pounds.

Their normal lifespan is between 10 and 14 years. They frequently have enormous broadheads that are proportionate to their stature, as well as pronounced cheek muscles and large skulls.

Their physique are strong and muscular, and their mouths are clearly defined. They look to be quite strong because of their broad chests.

2. American Classic Bully

The Classic Bully has a slimmer body form and a significantly lower body mass, but still displays “bully” characteristics. It appears similar to either the American Staffordshire Terrier or the original American Pit Bull Terrier.

The Classic Bullies have the same traits as the Standard Bullies despite being physically smaller. In comparison to women, who are typically 16 to 19 inches tall, men are typically 17 to 20 inches tall.

They normally weigh 60 to 80 pounds and have a lifespan of 10 to 12 years. The physical characteristics of the classics are an imposing chest, a slimmer body, and less muscles. They have large shoulders and muscular, slightly arched necks.

3. American XL Bully

The XL Bully resembles the Standard, despite being bigger and taller. They are the largest American Bully and considerably heavier than Standards due to their larger body mass.

Male XL Bullies can weigh between 70 and 140 pounds and grow up to a height of 20 to 23 inches. Females will grow from 19 to 22 inches at the same period while weighing the same as males.

hey have broad, deep chests and enormous, strong heads. They have distinct cheek muscles and a jawline that is sharply defined. Additionally, they have broad shoulders and muscular, slightly arched necks.

4. American Pocket Bully

They have many of the same characteristics as Standard Bullies despite being physically smaller. They have muscular bodies, big heads proportional to their stature, and big chests.

The average height of a male is 14 to 17 inches, whereas the average height of a girl is 13 to 16 inches. They weigh 20 to 50 pounds as well. They often live for 10 to 12 years.

Help your American Bully Grow Health

You can do the following to help your Bully grow health:


The high ratio of muscle in American Bullies requires a protein-rich diet. As dogs become older, said diet is even more crucial.

Puppies usually need more foods high in calcium to help their bones fortify and foods high in fat, which is a tremendous energy source.

Feed your American Bully nourishing food three times daily to give it the necessary nutrition to improve its genetics.


Because of their muscular build, American Bullies are known for having a lot of energy, which must be discharged and channeled via exercise and activities.

Once your puppy has received the necessary vaccinations, it should exercise for at least 30 minutes daily.

For instance, playing a game of fetch with your dog from an early age is a great way to teach obedience and build trust. They can also use all that extra energy by swimming.


You should start obedience training when you get home with your precious American Bully puppy. He will learn social talents and proper behavior around other canines and people through training.

Since Bullies are intelligent animals who thrive on praise, consider using treats to inspire during the training.

Vaccinations and Regular Vet Checks

As earlier said, the first step in caring for your dog is to provide a proper diet. Because veterinarians are qualified to do much more than check for ticks, having one on your side could benefit your American Bully.

Veterinarians can also give immunizations and recommend getting them. Additionally, they will aid in organizing more booster doses. Vaccinations are essential to keep your Bully healthy for many years to come.

Young puppies, mainly, are more exposed to infections since their immune systems have not yet completely developed.

Most vaccinations are injected between 6 and 14 weeks of age. The most typical vaccinations people receive are rabies, distemper, and adenovirus.

They can be lethal to humans and dogs on some occasions. Bullies may also be affected by COVID-19. The availability of vaccines is terrific news. Total immunity is achieved in around four months.

It is crucial to understand that immunizations do not work instantly after injection. They usually take a week or so to start performing. Besides, as necessary, booster shots can be administered.

Importance of Consulting with A Veterinarian

Throughout this article, I have mentioned and advised you to go to the vet if there is any problem with your American Bully. Even if your puppy has no issues, you should consult your veterinarian for regular checkups and dietary suggestions.

Your vet will not only suggest a diet but also measure your dog’s size, help with deworming and other vaccinations, measure weight, and check if anything is out of the ordinary.

The veterinarian will also suggest when to neuter/spay your Bully. Your vet knows best, and you should always take your vet’s advice regarding your American Bully’s health.

FAQs – Frequently Asked Questions

How Do I Bulk Up My American Bully Puppy?

Feed them a nutritious diet enriched with protein and calcium to bulk up your American Bully puppy. There must also include a good amount of fat as well. For further guidance, consult your vet for dietary supplements.

Why is My Xl Bully Not Growing?

An XL American Bully will keep growing for about 24 months of age. An XL is a large dog, so if you are worried that it’s larger than standard Bullies, that’s because it is.

If the Bully does not stop growing after 24 months, go to your vet immediately, but you can also go to the vet before that for regular checkups.

How Big Will My American Bully Puppy Get?

There are four American Bullies sizes, ranging from 14 to 23 inches. It depends on which class of American Bully you have and how good their health and diet is.

How Big Is a 10-Week-Old American Bully?

A 10-week-old American Bully is small and still a long way from adulthood. However, it is the perfect time to socialize with other people and dogs. The size will matter on the class of the dog.


The Bully growth chart will be helpful if you are a first-time American Bully owner. It is necessary to keep your Bully healthy.

To give your sweetheart American Bully the life they deserve, you should follow the growth chart and care for their health.

You can collaborate with your vet and breeder to ensure a steady growth and health plan. Doing all this will give you peace of mind and a good life for your Bully.

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