When Does An Australian Shepherd Stop Growing? What to Expect As Your Aussie Grows Up!

The Australian Shepherd is bred in two sizes today: standard and miniature. They’ll be fully grown within 12-16 months.

One thing many first-time dog owners don’t realize is that a dog’s adult size can really influence how long it takes that dog to grow up.

Why is it important to know when your Australian Shepherd will stop growing?

It’s important for all kinds of reasons, but one of the most important is because you’ll need to restrict too much exercise until your dog is fully grown.

We’ll go over why this is mandatory to prevent lifelong health problems and how to tell for sure when an Australian Shepherd standard or miniature dog is done growing.


When Does An Australian Shepherd Stop Growing?

The eventual size of your Australian Shepherd will greatly influence how long it takes them to stop growing.

In general, small dog breeds finish growing faster than larger breeds. The Australian Shepherd is no different. 

A miniature Australian Shepherd dog will be fully grown in one year, while a standard size Australian Shepherd may take as long as 16 months to grow up.

Compare this to a related Shepherd breed like the German Shepherd, which can take up to three years to completely finish growing!

Watch An Australian Shepherd Puppy Grow Up

This adorable owner-made YouTube video shows how quickly a standard Australian Shepherd puppy can grow up.

The video takes you through day by day, all the way up to the point when the puppy is eight months old. As you’ll see, there’s a pretty dramatic transformation!

What Is the Size of an Adult Standard Vs Miniature Australian Shepherd?

According to the American Kennel Club (AKC), the typical Australian Shepherd dog will weigh between 40 and 65 pounds and stand 18 to 23 inches tall (paw pads to shoulders) when fully grown.

Also, adult standard Australian Shepherd male dogs tend to outweigh adult female Australian Shepherds by up to 15 pounds and stand at least two inches taller.

This is a difference of anywhere from 20 to 45 pounds and five to 10 inches in height.

Contrast this with the much smaller size of the miniature Australian Shepherd, which the AKC states weigh between 20 and 40 pounds, and stands 13 to 18 inches tall when fully grown.

Here, adult miniature Australian Shepherd male dogs tend to outweigh female adult dogs by up to 10 pounds and stand at least one inch taller.

Why Is the Growth Cycle Longer for a Standard Size Australian Shepherd?

As previously mentioned, a standard size adult Australian Shepherd is going to have a lot more growing to do than a miniature Australian Shepherd – going from a tiny newborn puppy to a full-size adult dog takes time!

This tends to hold true across the board for large dog breeds. The larger the dog, the more growth must take place in every way, including bones, skeletal system, soft tissues, organs – everything.

So while you can expect your small to mid-sized Australian Shepherd puppy to complete the necessary growing in 12 months, your medium to large-sized Australian Shepherd puppy is going to need more time – at least four months more on average.

Why Is It Vital to Your Aussie’s Health to Know When They Are Done Growing?


According to the Canine Health Information Center (CHIC) database, Australian Shepherds are genetically prone to inherit two potentially disabling joint malformation issues: elbow dysplasia and hip dysplasia.

Both joint issues can potentially be prevented when a conscientious breeder orders pre-breeding screening tests.

However, not every breeder knows to do this or chooses to have the tests done.

The term “dysplasia” basically translates to mean “abnormal growth.” When that abnormal growth takes place in a dog’s major joints such as the elbow and hip, it can mean a lifetime of pain or lameness.

Canine dysplasia may be inherited, but it can also be worsened by Australian Shepherd growth spurts or prematurely taking on strenuous exercise.

In other words, your Australian Shepherd may have a mild case of dysplasia that will get much worse if your dog grows too fast or exercises too vigorously before they’re done growing.

How Can You Know Your Australian Shepherd Dog Is Done Growing?

There’s only one guaranteed way to know that your Australian Shepherd is done growing.

This method is fully reliable and applies regardless of gender or whether you have a standard or a miniature Australian Shepherd.

The one and the only way to confirm your Australian Shepherd has stopped growing is to have your dog’s veterinarian take X-rays of the long leg bones.

At the top of each long leg, bone meets an area of cartilage called the “growth plate.” This growth plate, like its name suggests, is like the computer of the dog’s leg. 

It sends out instructions, such as “keep growing” or “stop growing.”

The type of instructions each growth plate sends out can be changed based on what (and how much) your dog eats, type and duration of exercise, timing of a neuter/spay surgery, individual and breed canine genetics, among other factors.

When your Australian Shepherd has stopped growing for good, the growth plates will harden and close. This means that there will be no more growth instructions sent out.

Your dog is as tall as it’s ever going to get.

Now, keep in mind here that your Aussie may still have some filling out to do in terms of reaching their full adult weight (not an overweight Australian Shepherd). The growth plates only affect your dog’s height.

Why Would an Australian Shepherd Dog Grow Too Much?

There are several key reasons to be aware of that can explain why an Australian Shepherd dog might grow beyond what is considered healthy.

Feeding the wrong diet

One of the main reasons that an Australian Shepherd dog might keep growing is if the dog is fed the wrong diet.

A miniature Australian Shepherd puppy should be fed a small breed complete and balanced puppy food until the age of 12 months or whenever your veterinarian instructs you to transition to small breed adult dog food.

A standard size Australian Shepherd puppy should be fed a medium breed complete and balanced puppy food until at least 12 months of age.

Your veterinarian will be able to best advise whether to continue beyond 12 months or transition to an adult balanced diet then.


Too much vigorous, sustained exercise

The Australian Shepherd dog is a lively, smart, active working dog breed that was originally developed for livestock herding.

So these dogs are used to being on the go all day, every day, often for long stretches of time.

When bringing home an Aussie puppy, you can count on it needing a lot of exercises!

This will only increase as your puppy develops more coordination and begins to explore the great outdoors – these dogs love anything that involves running, jumping, and catching.

However, Animal MRT explains that some caution is needed when doing hard exercise. 

If your dog accompanies you on a long hike or takes on anything else that can put pressure on growing joints, damage can be done to the soft cartilage growth plates at the top of each leg bone.

If the growth plates are damaged before they harden and close, they won’t send out the proper instructions to the bones regarding when to stop growing.

You risk having a dog that goes through uneven growth on either side of the body. 

For dogs with a history of hip or elbow dysplasia (inherited), the added joint pressure can increase the amount of malformation that occurs.

Various types of structural damage can occur if you don’t carefully monitor your dog’s exercise. This needs to be tracked until X-rays confirm that the growth plates have hardened and closed.

But once you get the ‘green light’ from the X-rays, your dog can do all the running, jumping, and playing they want!

It’s worth waiting a little longer to be sure your dog’s body will be structurally ready, healthy, and strong enough to enjoy an active life with you.

Our YouTube Video On The Growth Of An Australian Shepherd

Detecting Joint Problems in a Rescue Australian Shepherd Dog

If you’ve rescued an adult Australian Shepherd dog that appears to be having joint pain and/or movement issues, the best thing to do is to have X-rays taken – this is the only way you’ll really know what’s going on.

Your canine veterinarian can help identify any past abnormal growth or joint malformation.

They’ll be able to provide you with guidance regarding rehabilitation, pain management options, and even joint surgery in severe cases.

During puppyhood, always watch for any signs of lameness in your Australian Shepherd puppies, including favoring one limb, limping, whimpering or whining, licking at an area, not wanting to play, refusing to get up, or ‘abnormal’ signs.

There are countless options available today to help Australian Shepherds suffering from joint or growth issues. 

You should always contact your veterinarian when looking at treatment options as they’ll be the safest and best resource you can find. 

Hopefully, you’ve enjoyed this little lesson on Australian Shepherds, feel free to keep scrolling for more Shepherd tips, tricks, and facts!

Gayle Judd

Wednesday 26th of May 2021

This is very valuable information. We have a 5 month old mini aussie. No one told me about the exercise routine and growth. We have been throwing the ball and letting him catch, jumping up and down and had no idea. Now I'm concerned. Why didn't our vet tell us this or the breeder??


Friday 8th of January 2021

My puppy and I enjoyed the videos of the puppy growing everyday.

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