Unlocking Puppy Growth Secrets: When Does Your Furry Friend Really Stop Growing?

Ever noticed how adopting a tiny, wobbly puppy feels like inviting a lightning bolt of energy and chaos into your life? One minute, you’ve got this cuddly fluffball snoozing in your lap—and before you know it, poof—they’ve morphed into a stubborn little rebel ignoring all your hard-earned training. It’s wild how quickly they grow, isn’t it? Sure, they don’t quite sprout overnight like a Jack-in-the-box, but compared to us humans, their puppyhood zooms by like a bullet train. And, as you might guess, each puppy’s timeline is as unique as their paw prints. From the pint-sized Papillons speeding through growth spurts, to the lumbering giants like St. Bernards taking their sweet time—there’s a whole world of curious facts about when and how puppies truly stop growing. So, if you’ve ever found yourself blinking in disbelief as your little companion turns into a full-grown dog faster than you can say “sit,” you’re in the right place to unravel this fascinating pup puzzle. LEARN MORE

If you’ve ever adopted a young puppy, it probably felt like they grew up overnight. One day they’re a small bundle of fur, and the next they’re a rebellious teenager ready to ignore everything they’ve ever been taught. OK, so puppy growth isn’t quite that fast, but compared to humans it’s still pretty quick. It’s also different for every puppy.

At What Age Do Dogs Stop Growing?

One of the biggest factors affecting puppy growth rate is their breed. As you can see in the puppy growth chart below, small breeds like papillons will reach their mature size and weight a lot faster than giant breed pups like St. Bernards who can take up to two years to fully mature. Of course, every puppy is different, and some may grow faster or slower than the average growth rate of their breed.

Puppy Growth Stages

Puppies grow at different rates, but most puppies experience their biggest growth spurt between 3 and 6 months of age. Somewhere between 4 and 8 months is when most dog breeds (except giant breeds) will reach 80 percent of their adult weight. Even after they’ve reached their mature size they still continue to develop, adding fat and muscle for several more months.

How Long Is a Dog a Puppy?

Puppies become adult dogs when they’ve stopped growing, which is generally around 1 to 2 years of age. Small and some medium dog breeds reach their mature size slightly earlier at 8–10 months whereas other medium breeds take 9–12 months to reach their adult size. Larger breeds take 11–15 months to reach mature size, and some giant breeds can take 18–24 months to reach their massive size.

When Do Puppies Start Walking?

For the first two weeks of a puppy’s life they are completely reliant on their mom. They can’t walk, their eyes are closed and their ears haven’t fully developed yet. They rely on their sense of smell to find their mom and their next meal. Around two to three weeks is when puppies will start learning to walk and begin to open their eyes. Their ear canals open around three weeks of age.

When Are Puppies Teenagers?

Puppy adolescence begins around 6 months of age when the puppy is becoming sexually mature and ends around adulthood. You may notice that they’re ready to explore more confidently and independently and willing to push the boundaries like a rebellious teenager. Training a puppy can be difficult during this period and they may be more reactive to new dogs and situations which is why continued socialization is important during this time.

When Do Puppies Calm Down?

This can be a hard question to answer as every puppy is different. In general, puppies have probably calmed down significantly by 12 months of age. However, there are some breeds, like the German shorthaired pointer, that are known to keep their playful puppy exuberance well into adulthood. Other dogs will remain active and need plenty of exercise and mental stimulation throughout their whole life, in essence, never really “calming down.”

Do Puppies Need Special Puppy Food?

All that growth needs fuel which is why a growing puppy has different nutrient requirements than an adult dog. In particular, puppies have a greater requirement for energy (calories), protein, amino acids, calcium, phosphorus, copper and zinc. Puppies can also benefit from increased amounts of the omega-3 fatty acid, DHA (docosahexaenoic acid) which helps support brain and vision development.

When choosing a food for your small or medium breed puppy (dogs less than 70 pounds as adults), look for one formulated for puppies or one that is formulated for “all life stages.” This will ensure your puppy’s nutrient needs are met.

Large and giant breed puppies have different nutritional requirements than small and medium dog breeds. The American Association of Feed Control Officials (AAFCO) uses a mature size of 70 pounds and greater as the definition for a large breed. If your puppy is one of the larger breeds, look for a dog food label that says “large breed puppy” and has this AAFCO statement, “Formulated to meet the nutritional levels established by the AAFCO Dog Food Nutrient Profiles for All Life Stages including growth of large size dogs (70 lb. or more as an adult).” Larger dog breeds need a puppy formula that promotes a steady, healthy growth rate as a rapid growth rate can cause bone and joint problems.

Puppies grow at different rates depending on their size, breed and genetics. You can help your furry friend grow at a healthy rate by feeding them a diet that provides all the nutrients their growing body needs. Ask your veterinarian which diet is right for your growing puppy.