Skip to Content

Why is My Aussie Not Growing?

If you’re new to owning Australian Shepherds, also known as Aussies, you may be wondering at what age they typically stop growing. Maybe it seems that your Aussie puppy has stopped growing before you expected him to, or you’re simply wondering what to expect when your dog reaches adulthood. What causes an Aussie to stop growing, and at what age is this normal?

The most common reason an Australian Shepherd stops growing is that they have reached physical maturity. For standard Australian Shepherds, this happens around the age of 16 months. Other reasons could include malnutrition and health problems.

So how can you know for sure why your Aussie isn’t growing? What are their typical growth stages? Read on for answers to these questions and more.

Australian Shepherd Sizes

Reasons Why an Australian Shepherd Isn’t Growing

Aussies make for friendly and loyal companions, so if it seems like your Aussie may have stopped growing before their time, it’s natural to feel concerned. Fortunately, there are very few conditions that could cause your dog to stop growing unnaturally, and as long as he is well cared for, you should have very little to worry about.

That said, let’s take a look at the most common reasons why your Aussie may have stopped growing.

Your Aussie Reached Maturity

This is by far the most common reason any dog stops growing, and it is, of course, perfectly natural. Most Australian shepherds reach maturity by the time they’re 16 months old, though if you have a mini-Aussie, he will probably be full-grown by his first birthday.

Typically, a full-grown standard Aussie will stand between 18 and 23 inches tall (measuring from the shoulders to the paw pads) and will weigh 40 to 65 pounds. Mini Aussies, on the other hand, will stand just 13 to 18 inches tall and weigh between 20 and 40 pounds when fully grown.  

In both standards and miniatures, the females are usually smaller than the males in both height and weight.

Your Aussie May Have Been Malnourished

This is extremely rare among Australian shepherd puppies raised in loving households, but may sometimes be seen in rescue dogs. Any dog that has not been given the proper nutrition may experience stunted growth. Depending on the severity of the malnutrition, they may stop growing altogether.

Malnutrition could come in the form of not being fed enough or being fed the wrong kinds of food. Both are forms of starvation.

Both mini and standard Aussies should be fed a complete and balanced diet appropriate to their age. Talk to your vet about how much to feed your young dog and when to begin transitioning to adult food.

They May Have an Underlying Health Condition

Again, this is quite rare, as Australian Shepherds are known for being exceptionally healthy dogs. That said, no dog is completely immune to all health concerns. 

Aussies are most commonly prone to hip and elbow dysplasia and eye conditions, neither of which cause them to stop growing. However, other conditions such as internal parasites and portosystemic shunt (a liver condition) may cause stunted growth. 

If a medical condition is responsible for stunting your Aussie’s growth, it will likely present with other symptoms as well. If your dog begins to act strange or uncharacteristic in any way, it might be a good time to schedule an appointment with your vet.

When Do Australian Shepherds Stop Growing?

Australian Shepherd puppies stop growing naturally when they reach full maturity. As mentioned above, this is usually around 12 to 16 months depending on whether it’s a miniature or standard Australian Shepherd.

That said, the only sure way to know if your Aussie has stopped growing is to get X-rays of his long leg bones. Growth plates, or cartilage at the ends of the leg bones, are what signal the dog’s brain to keep growing. These plates will harden and become closed off when the dog is completely done growing.

X-rays can show whether these plates have closed. If they have not closed, this means they are still active and the dog is not finished growing. If the plates have closed, you can be confident your Aussie will not be doing any more growing.

What Are the Growth Stages of an Australian Shepherd?

To understand when your Aussie is likely to stop growing, it may help to investigate the different growth stages the puppy will go through to reach maturity.

Birth to 2 Weeks

The weight of a newborn Aussie pup may vary, but it should double within the puppy’s first week of life. During this time, the puppy cannot see or hear because its eyes and ears have not opened yet. It is fully dependent on its mother.

3 to 12 Weeks

Puppies are ready for adoption by 8 weeks. By that time, their eyes and ears have fully opened, and they are able to wag their tails and bark and run around. When they reach 12 weeks, they will likely weigh between 18 and 25 pounds.

4 to 6 Months

Around four months, Aussies will begin to lose some of their puppy-like features and look more like a small adults. They will enjoy playing and socializing during the 4-6 month period but shouldn’t be exercised too strenuously, as this may increase their risk for developing dysplasia.

By the time the dog is six months old, his adult coat will begin replacing his baby fur. He will be at his “teenager” stage and may begin showing signs of disobedience, so proper training is crucial.

During this period, male Aussies should weigh between 32 and 45 pounds, while females should weigh between 23 and 33 pounds.

7 to 9 Months

Seven- to nine-month-old Aussies continue growing and becoming more mature, and they can begin exercising more and more. They should still be exercised with care though, and not allowed to overstress their still-developing bones and joints.

Male dogs will likely weigh between 49 and 56 pounds at this time, while females will weigh between 36 and 40 pounds.

10 to 12 Months

Aussies will most likely reach sexual maturity during the 10-12 month period. That said, standard Aussies will probably have to grow a bit more before they are done growing. Male dogs will probably be between 58 and 60 pounds, and females should be around 42 to 43 pounds.

12+ Months

Aussies will most likely reach maturity within the first few months after their first birthday. Males will probably weigh around 64 pounds, and females will weigh around 45 pounds.

At What Age is a Standard Australian Shepherd Full Grown?

Standard Australian Shepherds are usually considered full-grown when they reach 16 months old. Some may mature slightly faster or slower, so again, the only way to know that they have stopped growing is to get their long leg bones X-rayed.

If you don’t want to get X-rays, however, it’s a pretty safe bet that your dog will be fully grown after 16 months.

At this time, you can stop taking it easy with their exercising and allow your Aussie to run around and work as hard as he wants, as there will be no more threat of damaging developing growth tissues.

Final Thoughts

If your juvenile Australian Shepherd seems to be growing too slow or not growing at all, you may want to review the different growth stages of Aussies and check with your veterinarian if they present with any other symptoms. Keep in mind, that their growth will slow as they mature toward adulthood, and they should stop growing altogether around 16 months.

Related Posts