One of the most exciting experiences of owning a puppy is watching your young, cuddly friend grow up. But how old does a dog have to be to be considered an adult?
In most cases, a dog is considered an adult at 12 months of age. At this point, most dogs are physically full grown. Smaller breeds can also be physically mature at 6 to 8 months. However, large-breed puppies take about two years to reach physical maturity and be considered adults.
However, just because your puppy is 12 months old and physically mature does not mean it is mentally mature.
It may take until 18 months of age for him to stop acting like a puppy and shed his erratic and excitable behavior.
In this article, we will talk about the different milestones of puppy maturity.
In addition, we also go over the signs that indicate your puppy has grown up.
And we also reveal when a puppy should be introduced to adult dog food.
Table of Contents
At What Age is a Dog an Adult?
12 months is generally considered the age at which a dog is fully grown or adult. But it’s not that simple.
If you’ve owned more than one dog in your life, you know how different they can be. Some grow up faster than others.
So there is no fixed age, but rather a point of reference in terms of time. While some say that dogs are considered adults at one year, others may have a very different view of things.
How Does a Puppy Mature Into an Adult Dog?
When people say small but mighty, they can probably only mean puppies.
These adorable little dogs fill our lives with happy, precious memories. Let’s just forget about their stubbornness for a moment.
If you are privileged enough to have a puppy, you will eventually stare at your dog in amazement because he looks so grown up.
It’s an honor to take care of a puppy and watch it grow into a gorgeous adult dog that still warms your heart just as it did when you brought it home.
Like most things in life, puppyhood has an expiration date. It doesn’t last forever.
If you’re wondering how old a dog should be to be considered an adult, you’re not alone. This question crosses the minds of many puppy owners.
A puppy is not considered an adult until it has completed its physical development.
For most dogs, the physical growth process is complete by one year of age.
For this reason, experts generally agree that a one-year-old dog is an adult. He is then usually physically mature.
However, large and giant breed puppies can take up to two years to complete their physical growth and be considered adults.
However, small and medium breeds usually mature after 6 to 8 months, which is much faster than large dog breeds.
This is because large dogs still have a long way to go in terms of bone and muscle development and eventually reaching their full size.
When Do Puppies Become Adult Dogs?
The following list shows what research says about the physical maturity of different breeds:
- Small breed puppies reach their adult size at about 6 to 8 months of age.
- Puppies of medium breeds reach their adult size at 12 months.
- Large to very large breed puppies reach their adult size at 12 to 24 months of age.
Emotional Maturity and Sexual Maturity in Dogs
Even though your one-year-old puppy is already considered an adult dog, he still exhibits typical puppy-like behaviors that indicate he is not yet an adult. The reason for this is that he is not emotionally mature yet.
The dog may be a year old, but his adult behaviors are nowhere in sight.
In general, dogs do not reach emotional maturity until they are about 18 months to 2 years old. At two years, the dreaded puberty phase ends.
Emotional immaturity is often the reason most new dog parents wonder if living with their furry roommates will ever get easier.
If your dog is not emotionally mature, he will be difficult to deal with. But when he finally reaches emotional maturity, you’ll thank the heavens, believe me.
You will notice some of the following positive adult behaviors:
- They are less afraid of strange places or people.
- Their attention span is much better, they are not as easily distracted as they were in puppyhood.
- They respond very well to commands from obedience training.
- They respond better to signals from other dogs in the environment.
- Their destructive chewing habits subside and they respect your boundaries better.
- They have a calmer demeanor. They relax rather than chase butterflies.
- They have become fully accustomed to being in the home and do not cause trouble for other pets.
In addition to physical and emotional maturity, your dog also reaches another milestone – sexual maturity. However, this milestone takes place before the others.
Most female dogs are considered sexually mature when they are six months old. They go into heat for the first time and get their period.
However, female puppies of large breeds are an exception. Their first heat cycle begins a little later, at the age of 18 months.
Sexual maturity means that your not-so-young puppy is able to reproduce.
However, this milestone also brings unpleasant behaviors that will make you doubt your puppy’s innocence.
The first heat may give you the impression that your puppy is officially an adult. But in truth, they are still young at heart, and physically too.
That’s why experts often advise puppy parents to make sure their little dogs don’t get pregnant during their first and even second heat.
Even though they are sexually mature, they are still emotionally and physically immature. It’s not nice when a female puppy is already faced with the responsibility of being a mother at such a tender age.
Also, her body is not strong enough to carry babies.
Besides physical growth, there are other signs of maturity that will confirm to you that your puppy has entered the next chapter of life – adulthood.
- The mouth is full of adult teeth. During puppyhood, a dog often has trouble teething. By the time they are six months old, all of their baby teeth have fallen out, making way for adult teeth. So when you see your little puppy with adult teeth, you know it’s not little anymore.
- The texture of the coat will change. At some point, you will notice that your puppy is shedding quite a bit. This happens when your puppy grows out of his super soft hair and can grow the coarser adult coat.
- They won’t have as many potty accidents as they used to.
Transition from Puppy Food to Adult Dog Food
As your little furry friend grows up, their nutritional needs change as well. The days of puppy food will come to an end.
When your small or medium-sized dog turns one year old, you should switch to adult dog food. If you have a large breed of dog, you should use puppy food until your dog is two years old.
Be sure to consult with your veterinarian when making the switch to protect your four-legged friend from serious nutritional problems.
You may be wondering why switching to adult food is so important.
Well, puppy food is tailored to meet the exact needs of a growing puppy. It contains extra nutrients to meet your cheeky pup’s high-energy needs.
In addition, this food promotes the growth of bones, muscles, organs, and joints.
When your young dog is an adult, he no longer needs all these extra nutrients for growth.
Instead, adult dogs need a whole range of nutrients to live a healthy and fulfilling life. Adult dog food provides just that.
Most dogs eat less as they grow up. When a puppy grows up, they need more food because they are constantly active.
But when they become adults, their energy needs decrease. They don’t need to eat as much then – eating twice a day will be enough.
Summary: When is a Dog Considered an Adult?
As a rough guide, a dog can be considered an adult from the age of 12 months. However, this refers to the physical growth.
In small dog breeds, growth is already complete after 6 to 8 months. However, in large dog breeds, it can take up to 2 years before the dog is fully grown.
Another issue is emotional maturity. Even when a dog is physically fully grown, it usually continues to act like a puppy for quite a while.
So during this time, you will continue to need the patience that you already had to show as a puppy parent.
Sexual maturity also differs from physical maturity. Bitches can be sexually mature as early as 6 months.
However, you should be careful that your bitch does not have offspring too early. As long as she is not physically full grown, pregnancy can be a danger for the bitch.
An important point about growing puppies is that you should change the food once the puppy is fully grown. Adult dogs need different nutrients than puppies.