There are several factors contributing to your pup’s growth. And for the benefit of curious dog owners like you, listed here is the very simple guideline you can use as a reference to check when your pup will stop growing!

So, When Do Dogs Stop Growing EXACTLY?
The honest answer to this question is this: it varies. A number of factors such as health and nutrition play a crucial role to your pup’s growth rate. Add up to the fact that there are some dogs that may categorically belong to “exceptional cases” in terms of growth, too. And if you even try to put everything into perspective – that will only result in more questions than answers.
It may sound daunting but fur parents like you can use this important information to somehow, give you a best “estimate” to this timeline: your dog’s breed. And for easier reference, these are split into four simple categories: small, medium, large, and extra-large!
Now, when we talk about growth, this means both physically and mentally. Pups are like children. They grow in size as much as they develop their brains to mature. And as a bonus, there is a separate section that briefly talks about mental growth, too!
Physical Growth: The Stages
Before we categorize your pup’s growth according to breed, let’s take a closer look at the stages of physical growth. On a high-level, physical growth are the changes extremely visible to you. Whether it is the bigger frame or the stockier muscle of your pups – these are all part of physical growth. But do you know that these developments are done in two stages? And every breed goes through the same phases, too!
The first stage is the rapid growth and more likely the time you also notice your pup needing lots of food to compensate for this stage. It usually occurs from birth and can last until your pup reaches four to five months of age. At this time, your pup’s framework (skeleton) swiftly grows longer, made possible by the gap located at the ends of their limb bones also known as “growth plates”. These plates are cleverly named as such as the “space” between the plates contains rapidly dividing cells. These are the cells to thank for your pup’s rapid first phase of physical growth, too!
The second phase is slower and the duration may vary according to breed. Your pup’s skeleton still grows but not as much as it did during the first phase. At this stage, the changes involved with your pup’s bones and muscles are more on the finer details – so these may or may not be as visible to you. During the second phase, the gap between the growth plates slowly thins out as a result of hormonal changes in your dog’s body. The plates will continuously get thinner until it eventually closes once your dog reaches full adulthood.
And now that you know the two stages of physical growth, let’s look at the different estimated growth timelines by breed.
Small-sized dogs
Small-sized dogs are the Chihuahuas and Yorkshire Terriers. Dogs falling under the “toy breed” category generally reach their full-sized adult body frame once they reach 10 to 12 months of age.
Medium-sized dogs
Medium-sized dogs are the Beagles, Toy Poodles, and Mini Schnauzers. If your dog belongs to this category, it is very likely they will reach their adult height when they are between 12 to 15 months of age. It is possible they will continuously gain weight until around 18 months, though!
Large-sized dogs
The likes of the Golden Retrievers and Collies belong to the large-sized dog group. Dogs in this category are expected to grow in height until they reach 18 months old. And because these dogs are more muscular, they may continue to gain weight until they reach 2 years of age.
Gentle giants such as the Great Dane belong in this category. And similar to the large-sized dogs, they can grow in height until they are about 18 months old. However, unlike the large-breed dogs, the giants can continuously gain weight until they are about 3 years of age!
Mental And Social Maturity
Mental and social maturity is also an aspect that develops as your pup grows into adulthood. And unlike physical growth, the timeline for your fur baby’s mental maturity is relatively the same regardless of breed. From birth up to 2 weeks, pups have their eyes and ears closed – so they are very dependent on their Mom for everything. Once he/she reaches 4 weeks, he/she starts to have a better understanding of his/her surroundings. Between 4 to 12 weeks, your pup will become a bit more adventurous – you may notice he/she is beginning to play with his/her siblings, too! And by the time your pup is around 6 months of age, the experience is almost similar to having a teenager at home. Your pup will start to test the limits (even you!) or try to push boundaries while continuously learning about the world he/she lives in. Your dog will also show signs of seeking his/her “place” within the community/household. And his/her brain will mature until around 1 to 2 years of age.
Exceptional Cases
Of course, there are ALWAYS exceptions to the rule – dogs included! Mixed bred dogs easily falls under this category – especially those with parents belonging to different size categories! And in such cases, in order to have the closest growth estimate for your pup, you may have to consider BOTH parents’ breed.
Growth Expectations For Your Pup
All loving and concerned fur parents like you wants your fur babies to reach his/her maximum potential – and that includes growth. Because of this, it is crucial to have the best estimate to the question “when do dogs stop growing?” so you know whether your dog needs to address any health concern putting his/her development (or life) at risk.