Written in collaboration with vets
When do dogs stop growing? Well, the answer to that isn't quite as simple as you may think. There are various factors that influence growth rates and timelines in dogs. In this post, we'll explain everything as simply as possible. We'll share what goes into your dog's development from puppyhood to adulthood.
Like humans, dogs grow when cartilage at the ends of their bones (growth plates) steadily turns to bone in a process called ossification. When the growth plates close, no further bone elongation can occur. The rates of bone growth and plate closure depend partly on nutrition. This is why it's essential to feed complete and balanced puppy food throughout their growth period, ensuring that the key nutrients, vitamins and minerals are all in the right amounts and ratios to support healthy growth.
Trauma can also prematurely close growth plates. Around 12–18 months for most dogs, the growth plates will fuse and harden into solid bone once maturity is reached. This signals that vertical growth has stopped. Generally, large and giant breeds are slower to reach maturity because their larger bone structure requires more time to fully develop.
A dog's adult size and rate of skeletal growth depend on both genetics and environmental factors. Let's look closer at some of the key influences of puppy growth.
One of the biggest determiners of your dog's adult size is its breed. This is one of the key factors you have to pay attention to when getting a puppy. Some toy breeds, like Yorkshire Terriers, reach their full-grown height as early as 6-8 months old, but they will continue developing until they are a year old.
Large and giant breeds, which have much bigger bones and joints to develop, can take anywhere from 18-24 months to reach their adult size.
The food your puppy eats fuels its growth. Without proper nutrition, your dog may not reach the maximum growth potential. Typically, pup feeds with lots of nutrients and minerals are ideal for development. A growing puppy needs complete and balanced puppy food, this means that the nutrients are tailored to support their healthy growth and development. It is essential that the food contains all of the nutrients they need, as well as that the minerals are in the correct ratio, giving peace of mind that your puppy is eating everything it needs for the best start in life. Consult your vet for feeding recommendations tailored to your puppy's needs.
When puppies are first born, they rely completely on their mother's milk for nourishment and antibodies. They'll need to feed from mum every couple of hours in the beginning.
By about 3-4 weeks old, puppies can start the weaning process, gradually transitioning to solid food over the next few weeks while still nursing periodically. Keeping puppies warm, clean, and well-fed assists their early development.
Now, let's break down a puppy's development from birth through adulthood:
Age | Stage | Changes | Size |
3-4 weeks old | Weaning | Transitioning to solid food | Varies greatly between breeds |
3 months | Rapid growth | Teeth start to be replaced by adult teeth | 33%, varies greatly between breeds |
6 months | Slowing growth | Adult teeth emerging | 66%, varies between breeds |
1 year | Maturing | Reaching full height | Nearly full grown |
1-2 years | Full maturity | Filling out to full weight | Full adult size |
When you understand your dog's growth, it helps you know what your puppy needs as they mature. From puppyhood to adulthood, your dog will have to go through different developmental stages, which answers the question, when do dogs stop growing, more precisely.
Neonatal stage
The neonatal phase spans from birth to around 3 weeks old. As newborns, puppies cannot see, hear, or even regulate their own body temperature. They rely fully on their mom and their littermates to meet all their needs. Their first priority is to nurse frequently and grow rapidly. Their eyes and ears are open between 10-14 days old.
Transitional stage
During the transitional stage, from 3 to 16 weeks old, puppies take huge developmental leaps. Their baby teeth start to erupt, and they stand, walk, play, and explore their world for the first time. Weaning is between 3-4 weeks old.
Socialisation stage
From 3-14 weeks old, puppies enter the critical socialisation period. This is before they've learned a fear response, so providing as many new, safe situations and experiences as possible is key. They are eager to investigate new sights, sounds, smells, environments, objects, other animals, and people. These interactions build their ability to cope with change as adult dogs.
Juvenile
The juvenile phase lasts from 3 months to around one year old. Play behaviour peaks during this stage. Young dogs often seem to have boundless energy. Their adult teeth come in as baby teeth fall out. They may show sexual interest before reaching full maturity. It’s nothing to worry about, just normal dog behaviour.
Ranking stage
The ranking period, starting around 4-6 months old establishes the hierarchy between dogs. They figure out where they fall in the social structure of the family pack. Squabbles over toys, food or attention may occur. Reinforcing rules and training helps them understand the boundaries and behaviours that are desirable and undesirable.
Adolescence
From 1-2 years old, dogs enter adolescence - very similar to the human teenage phase. They undergo hormonal shifts as they near sexual maturity. Their energy levels rise. They question rules and limits and may have more difficulty concentrating. Patience, routine and consistency help them through this transition.
There are some signs that reveal when dogs stop growing. You just have to spot these signs in your puppy growth.
Here are a few giveaways:
Teething
Around four months old, permanent canine teeth start pushing out puppy teeth. By about seven months old, all adult teeth have erupted. You may not even notice the deciduous teeth coming away as most are swallowed during eating, but you will notice an increased desire to chew during their teething period so having lots of puppy-safe chew toys available at all times will help prevent unwanted chewing. Starting a daily oral care regime for your dog, such as toothbrushing is advised from 4 months of age.
Ear position
The ear canals typically open by 14-28 days old, but final ear carriage may take months to develop in breeds with ears that stand erect. Certain cartilage structures must harden to hold ears upright, and this often occurs around 5-6 months old.
Paw size
Puppies have disproportionately big feet. As your pup grows into its body, its adult paws will be more in proportion. But those adorably huge puppy paws give hints about future full-grown paw size.
Coat changes
During growth spurts of intense shedding, the mature coat comes in differently — longer, thicker and fuller. Adult dogs shed much less than rapidly growing adolescent dogs. Most large breed dogs hit their peak height between 10-14 months old.
The developmental journey from newborn through adolescence onward into fully mature adulthood is full of rapid changes. So, caring for your dog is significant during these changes.
Nutrition
Complete and balanced diets supply the fuel for healthy development. Puppy foods provide all of the nutrients, vitamins and minerals in the correct amounts and ratios to support healthy growth and development.
Training
Physical and mental exercise prevents boredom and unwanted behaviours. Learning boosts confidence and thinking skills. Routines allow dogs to anticipate what comes next. Physical exercise needs to be restricted to protect growing and developing joints, walking on a lead is much safer than running off-lead but all exercise needs to be monitored and supervised.
Patience and empathy
Much like human kids, young pups have bursts of energy between long naps. They forget rules in moments of excitement. Understanding what developmental stages they're experiencing allows realistic expectations of their behaviour. Tracking milestones, addressing problems early, and working closely with your vet provide supportive care tailored to your dog's needs in each life phase.
In the past few minutes, we’ve talked to some length on the question “when do dogs stop growing”. If there are some questions you’re still not clear about, we’ve tried to answer them here.
As mentioned throughout this guide, the age at full maturity depends significantly on breed and gender. While small dogs reach adulthood faster, giant breeds keep putting on height and fill out for over 18 months. Males also grow a bit faster and larger than females on the whole. When do dogs stop growing? Generally, males also grow a bit faster and larger than females on the whole.
Breed predictions give a general idea of adult size. Knowing what developmental stage they're passing through, you can roughly calculate size compared to full-grown proportions. For example, a medium-sized dog at 6 months old in the juvenile ranking period has likely reached about 75% of their adult dimensions, making it easier to estimate when dogs stop growing.
At 6 months old, dogs have often attained 60-70% of their full-grown height and length. So, your medium or large pup still has significant filling out to do through adolescence before total growth plates close between 12 and 18 months old.
While giant breed dogs may take up to 2 years to finish adding some height, most dogs have reached their adult size in terms of paw size, height and length by age 2. Females gain additional body fat starting around 2 years old.
