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When Does a Dog Stop Growing?

dogs touching noses

Fact checked by a Hello Ralphie expert veterinarian

One of the first things you will hear new dog owners mention about their recently acquired puppy is how quickly it is growing. It seems like one day your puppy is a cute little ball of fur, and the next day it has grown into an adult dog.

If you are wondering when your dog will stop growing, you are not alone. Veterinarians find that growth-related questions are some of the most commonly asked during puppy checkups and vaccine appointments. If you have any specific questions about your puppy’s health, make a vet appointment today to speak with a vet at Hello Ralphie.

If you have been wondering when your puppy will stop growing, we can help! To answer this common question, we will go over some of the factors that will determine how long your dog will continue to grow and information regarding average ages when different dog breeds reach their full adult size. From there, we will even explain what you can do to help your puppy develop and grow in the healthiest way possible!

Factors That Will Determine When Your Dog Will Stop Growing

How quickly your puppy will grow and what age it will stop growing depends on several factors, which is why there is no precise answer for when every dog will stop growing.

Genetics plays an incredibly important role when it comes to determining growth rate. Different breeds grow at different rates and reach their full adult size at different ages. In general, smaller dog breeds grow much faster than larger breeds because their larger bones and joints take more time to grow and develop.

Then, of course, other factors, like diet and exercise, will impact a dog’s growth rate. As you may suspect, healthier dogs tend to grow faster and larger.

What is the General Range?

For practical purposes, a dog is considered an adult once it has reached one year of age; however, a dog can continue to grow in height and length even into adulthood. Just because your dog is technically an adult does not mean it will automatically stop growing. Skeletal growth will continue anywhere within the 6-to-24-month range, depending on the particular breed and several other genetic factors.

Even when the bones have calcified and stopped growing, the dog will continue to develop fat and muscle. Think of your dog as a growing teenager. While some teenagers reach their full adult height at a relatively young age, some take much longer to reach their full height and properly fill out.

different types of dogs breeds laying together, isolated on white background

When Do Different Sized Breeds Finish Growing?

Since breed size is one of the most important factors for knowing when a particular dog will finish growing, we have provided some average ages for maturation below:

Small Sized Dog Breeds:

As mentioned above, small-sized breeds usually reach their full size relatively quickly. On average, small breeds, dog breeds under 25 lbs when fully grown, grow rapidly between 4 to 6 months and reach their full size between 10 to 12 months. This also generally applies to a toy breed, too, like a chihuahua, toy poodle, or Yorkshire terrier.

Medium Sized Dog Breeds:

Medium-sized dogs, those that weigh between 25 and 50 lbs when they are fully grown, will grow rapidly between 8 and 12 weeks and stop growing somewhere between 12 and 15 months. However, some breeds will even grow a little bit more beyond the 15-month limit.

Large Sized Dog Breeds:

Large breeds, dogs that land within the 50 to 100 lbs range, also do most of their growing between 8 and 12 weeks. After this point, the growth slows; however, the large breed dog can still take up to 18 months to finish growing.

Giant-Sized Dog Breeds:

Giant dog breeds, like Saint Bernards, Great Danes, or Mastiffs, take the longest time to finish growing. Their huge skeletal frames take a significant period to reach their full size.

Typically, the giant breeds will finish growing within 18 to 24 months; however, it could take as long as 3 years for a giant breed dog to reach its final healthy weight. This extended growth period is why Great Dane puppies tend to look so lanky.

What About Non-Purebred Puppies?

If your puppy is a mixed breed, or you do not know which type of dog it is, questions relating to growth rate are a little trickier to answer. One of the ways you can determine if a dog has finished growing is to run your hands down the dog’s rib cage. If you feel knobs at the ends of the ribs, there is a good chance the dog is still growing, as these knobs are the growth plates of ribs that are still developing.

man doing morning walk with his black labrador retriever dog

What You Can Do to Help Your Puppy Grow Properly

One of the best things you can do to encourage your puppy’s growth is to ensure you feed it nutritious puppy food that is specifically designed for the dietary needs of its specific life stage.

Purchase high-quality food that is appropriate for the dog’s age group. Low-quality and inappropriate dog food can cause a dog to become overweight, which will almost always lead to serious health issues as the dog ages. One of our virtual vets can go over all your nutrition questions and recommend appropriate portions and types of food to give your dog as it grows.

Exercise is also important as it will help your dog stay healthy. However, too much, or too strenuous exercise, can be a bad thing for a growing dog. Their bones and joints are still growing and are susceptible to injury, so you should be careful not to overwork your growing dog.

Schedule Your Growing Dog for a Virtual Veterinarian Appointment:

Speaking with an online vet is one of the best ways you can ask questions about growth rates and how you can make sure your dog grows properly. Our highly-qualified virtual vets can answer all of your questions and make an educated estimate regarding your dog’s growth rate and when it will stop growing. Make an appointment with a Hello Ralphie online veterinarian to talk to a vet online today!

If you have other questions, our New Puppy Tips guideline will tell you everything you need to consider when you bring a new puppy home!

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