Is there anything cuter than a baby pup? They’re super-soft to cuddle and their little faces are almost impossible to say “no” to. Even though we can’t get enough of our little furballs, in the blink of an eye, your miniature puppy can quickly grow to become your fully adult best friend. Still, watching your new puppy grow is one of the most exciting parts of being a pet parent. But, when does a dog stop growing? While no one can tell you for sure how big your puppy will get when it reaches adulthood, there are several factors that can provide you with some hints. When can you count on your dog to stop outgrowing his or her collars? It’s time to find out!
When do puppies stop growing?
As hard as it can be to admit, all puppies will become adult dogs one day (although a little less energy and chewing might be something to look forward to). The question is: When does a dog stop growing? Your dog’s breed, sex, and other genetic factors are crucial in determining your puppy’s future size, as well as when it will stop growing. You may have a purebred puppy and have a rough idea what to expect, but even then, Mother Nature might throw a surprise or two. Today, we take a more in-depth look into how dogs grow, when do dogs stop growing, when do they reach adulthood, and how big their dog might get.
When do dogs stop growing emotionally and reach maturity?
Puppyhood isn’t just about physical growth—it’s also when your puppy matures emotionally! Puppies go through several stages of emotional development as they grow. During the first 12 months of life, puppies explore and learn everything there is about the world. Your puppy’s emotional growth goes hand-in-hand with its physical development. Puppies typically develop the emotional maturity of an adult dog between 12 and 18 months of age, although they may continue to exhibit puppy-like behavior until they’re about two years old.
How do dogs grow? Stages of puppy development
Before we get into your dog’s adult age and size, you should understand the mechanism by which puppies grow. The growth rate of your puppy will largely depend on the rate at which the bones grow. Once a puppy gets to the adult stage, the bones stop growing. Although most people follow the old adage that a puppy is considered to be an adult once it reaches one year of age, puppies continue to grow in height and size as long as their bones are still developing, which takes anywhere from 6 – 24 months. Their skeletal growth is also what determines what size they will be as adults. Keep in mind that even after the bones are fully developed, your puppy will continue to develop fat and muscle, just as human adults do.
At what age do dogs stop growing?
Different dog breeds have different growth rates, so there isn’t a universal age at which puppies stop growing. There are a few factors that can help determine how long it will take a puppy to fully grow into an adult. In most cases, the larger the breed – the longer it will take for puppies to stop growing.
When do small dogs stop growing?
Small dogs at the pocket-sized end of the scale, like Chihuahuas or Terrier breeds, usually reach their adult size in less than a year. Some especially small dogs, like toy breeds, can finish growing in as quickly as six months.
When do medium puppy breeds stop growing?
Dog breeds of medium adult size, like Border Collies and Labrador Retrievers, might take a bit longer to develop than small dogs, and usually finish growing by the time they are 12 months old, give or take.
When do big dogs stop growing?
Your loveable large breed pup needs even more time to grow. Longer bones need more time to develop, so large dog breeds and giant breed dogs can take anywhere from 16 to 24 months to stop growing.
Other puppy growth and size factors
While your dog’s breed is one of the main factors that affect how quickly and how much your dog might grow, there are other factors that might determine when your puppy will stop growing.
Spaying / Neutering
Spaying and neutering puppies can alter the growth of your dog. Early neutering cancels out chemicals that tell bones to stop growing. Thus, early neuters have a tendency for long bones and are therefore taller, causing joint issues later in their life. Neutering a puppy between 22 and 37 weeks was shown to cause a short-lived upwards shift in the growth trajectory that quickly goes back to normal. But, for puppies neutered before 22 weeks old, it was more pronounced.
Sex / Gender
Male and female puppies of the same breed will grow at similar rates, and they’ll stop growing around the same time. But, females will generally end up being smaller than male dogs, which tend to be slightly heavier and larger than females of the same breed. However, female dogs tend to mature a little faster than male dogs.
Healthy nutrition
To support the growth of your puppy, it’s important that it is taking in and exerting the proper amount of energy. Puppies need more calories than adult dogs. Healthy, rich nutrition tailored to your pup’s needs will create a strong immunity and allow your puppy to grow into a healthy and happy adult dog.
How big will my dog get? Predicting your puppy’s size
Determining your puppy’s adult size can be a fun guessing game! Here are a couple of rule-of-thumb hints you can use to “guesstimate” your puppy’s adult size and weight. Puppy paws tend to be a good indicator since larger paws are generally a sign that the puppy will grow into a larger-sized dog and vice-versa. In addition to paw size, another hint when wondering how big your puppy will get is excess skin – typically, the more loose skin a puppy has, the more room it has for growth.
Predicting when your puppy pet will stop growing is a tricky subject to nail down. But, one thing is certain – while dogs may stop growing in size, the spot they take in our hearts only continues to grow. Proper socialization, nutrition, exercise, and a lot of love will help your canine pet thrive. Most of all, have fun with your puppy. There’s nothing quite so magical as watching your puppy grow up into a happy and healthy adult!

Jack was born and educated in Ireland and U.K. He has a varied education, mostly in engineering projects. Since then he has worked with a number of major companies with interests in various parts of the world. His personal interests include athletics, cross country skiing and especially long distance running. Jack has competed in many running events and some at an international level, including many marathons. He has always had a keen interest in maintaining a healthy lifestyle. More recently he has specialized in the areas of health and supplements, with a special focus on the immune system.