When Is a Dog Not a Puppy Anymore?

Dr. Jason Gagné, DVM, DACVIM
By Dr. Jason Gagné, DVM, DACVIM
Updated: 5/9/20242-4 minutes
When Is a Dog Not a Puppy Anymore?

A dog is no longer a puppy between 12 to 18 months with some variation based on breed, size and personality. Smaller breeds tend to develop and reach maturity sooner, both physically and emotionally versus large to giant breeds that can take up to almost 24 months before reaching adulthood.  

Puppies seem to grow up fast. One moment you’re bringing them home for the first time and watching them race around the house, a tiny ball of boundless energy. The next thing you know, you’ve got a full-sized dog cuddling up to you.  

During puppyhood, you have the responsibility of choosing a veterinarian, making sure they’re eating a complete and balanced puppy food, training, playing with them, and giving them tons of love and affection. So, when is a puppy not a puppy anymore? What are the emotional and physical signs?  

Puppy Energy Levels Start to Plateau

Puppies are highly energetic, whether it’s the zoomies, an insatiable drive to chew or the seemingly endless curiosity. As fun (and occasionally exhausting) as that is, it may be a relief once their energy levels start to taper off.  

This plateau in energy levels signifies your dog is becoming an adult dog. Just because they’re no longer puppies, however, does not necessarily mean they won’t still be highly excitable and energetic at times. 

Sleep Habits Change

Puppies need lots of sleep. Sleep helps puppies recharge their batteries, and it also helps them grow while benefiting the development of the brain, muscles, immune system and central nervous system. 

On average, a puppy will sleep around 18 to 20 hours a day, although it may not seem like it since they're so active during their awake time. As they reach maturity, you may notice the quantity of sleep decrease, as the average adult dog will sleep around 14 hours a day. Since not all dogs are the same, there might be slight variations to your dog’s sleeping habits compared to the average. 

Behavioral Changes

As puppies mature into dogs, certain behaviors most often associated with puppies begin to taper off due to training, physical and emotional maturity. For example, a puppy may run at full speed to greet you when you enter the house and might even try to jump on you. A more mature dog will likely be just as excited to see you but knows that if they’re calm, they’ll still get all the attention and praise they desire. 

Other signs your dog is reaching emotional maturity are better listening skills and obedience, decreased distractibility and an overall calmer demeanor. Being able to handle being alone while you’re out and about also indicates emotional maturity. If your adult dog has difficulty being left alone and engages in destructive or undesirable behavior, this could be a sign of separation anxiety and needs to be addressed.  

Another sign of the transition to adulthood is the decline in chewing and teething. Puppies use chewing to discover the world around them, to ease discomfort during teething and because chewing on things is enjoyable for them. With the onset of adulthood, your puppy will no longer need to chew on anything and everything.  

Puppies have small bladders and weak bladder control. Early on, accidents around the house are often caused by puppies not yet knowing where they’re supposed to relieve themselves or not yet having the bladder control to “hold it” until they can get outside. While they may be potty trained well before adulthood, it’s a sign they’re moving in the right direction and becoming physically more mature.  

Steps to Take as Your Puppy Matures

As you can see, the answers to the question, “When does a puppy become an adult dog?” are many, and they can vary depending on the breed and personality of your dog. Regardless, it’s good to keep track of your dog’s maturity and keep in close contact with your veterinarian so you’ll know when to transition to an adult dog food and other behavioral changes to expect.   

Discover more insights about puppies and dogs from our pet experts on our Pet Expertise page.

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