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An overview of puppy growth and development
presented by the experts at Purina Puppy Chow.

0 - 8 Weeks

First Impressions

Believe it or not, these eight weeks are some of your puppy’s most impressionable. His brain will undergo a big developmental spurt, which leaves a small window for him to learn everything he needs that will shape his personality and form his future behaviors. To start him off on the right paw, give him plenty of playtime with his littermates and shower him with human attention when he’s ready.

Development & Health: Body Control

Did you know that in his first seven weeks your puppy will gain almost full control of his body? Your pup will develop motor skills, be able to hold his bladder, use all of his senses and start growing baby teeth. There’s no need to guide him through these changes. Much like a baby walking for the first time, he’ll do this all on his own.

Behavior: Socialization

Welcome to the single most important part of your puppy’s life: his first socialization. This is the time when he starts learning the core of what it means to be a dog – how to play, bite inhibition, discipline and pack mentality. All these important lessons are learned by interacting with other puppies. So, make sure he has plenty of time to play with his littermates to reinforce the "puppy programming."

Nutrition: Puppy Food

Puppies usually start eating food around weeks three and four, and by weeks six to eight your pup should be fully eating puppy food. Some people wonder if they really need to feed their pup this specially formulated food. The answer is yes. Puppy food is high in calories and fortified with all the nutrients (like DHA) he needs to grow up big and strong. Small dogs will physically develop faster than large ones. So depending on your pup’s breed size, you’ll want to feed him puppy food for one to two years, and then switch to adult food. But we’ll cover that down the road.

8 - 16 Weeks

Learning the Ropes

Congrats on making it through the first phase of puppyhood. In the coming weeks, you’re going to see big changes as your pup’s brain goes through even more development and she better acclimates to the human world. You might not have had a huge hand in First Impressions, but this phase is focused entirely on you and your pup. So, get ready to form a strong bond and take an active role molding your little one into a well-behaved puppy.

Development & Health: Training & Shots

Puppy training starts the minute you bring them home. You might not always be actively teaching them, but their minds are young and constantly learning both good and bad behaviors. The best thing you can do is begin formal training as soon as possible. Teach your pup everything from where to go potty to walking with a leash to understanding basic commands like “sit.”

Make sure to give your puppy the appropriate vaccinations. Consult your veterinarian about scheduling and which are most important.

Behavior Milestone: Human Bonding

This is considered your puppy's second socialization stage. The first one was largely spent with the littermates and learning about being a pup. This time it's all about human interaction, bonding, and learning how to be a pup in the human world. Spend as much time as you can schooling and playing with her during this time. It's key to helping her learn good behaviors and shed the bad ones. With enough support, she'll grow into a socially confident and well-bonded pup. So, enjoy forming this new relationship.

Have you noticed your puppy biting a lot? Along with tail wagging and yipping, nipping is one of a puppy’s main methods of communication. Usually puppies will nip to get you to play. But psychologically it's a way for them to learn the limits of what they're capable of and how their actions affect those around them. During the first socialization stage your pup began to learn bite inhibition. If the lessons didn't fully sink in, it's up to you to teach her the boundaries.

Nutrition: Puppy Food

Puppies have unique nutritional needs. They need more protein for growing muscles, DHA to support brain development, and an appropriate level of calcium for growing bones. By week eight, your puppy should be eating a specially-formulated puppy food, which has a different nutrient profile than most adult dog foods to support her growth and development.

For the first six months, you should feed your puppy three times a day—morning, mid-day, and night. Also, size does matter: Large-breed puppies have different nutritional considerations than smaller breeds. So if your little lady will one day weigh 50lbs or more, look for a large breed puppy food (like this one from Puppy Chow) that’s specially formulated to ensure her bones and muscles grow big and strong.

4 - 6 Months

Growing Up

It’s helpful to look at these next few months as your puppy’s juvenile phase. Like a kid in elementary school, sometimes your puppy will be a perfect angel and other times he’ll be completely disobedient. Be patient with him. He’s figuring out his place in the world, and we all remember what that’s like. Just keep calm and make sure you keep him in his daily consistent routine so he knows what is expected of him. With your guidance, he’ll follow the rules sooner or later.

Development & Health: Growth Spurt & Sexual Maturity

Around this time your puppy will make a big leap in growing and get closer to his full size. That means you can expect an increase in his playfulness and energy levels. Depending on his breed, he may shed his puppy coat for his adult one, and grooming might help the transition. Be on the lookout for new chewing habits. It's a sign he’s teething and you'll want to try a few things to ease his discomfort.

Get ready for the birds and the bees. Between 4–6 months of age your pup will reach sexual maturity. Girls will go into their first heat and boys will take a keen interest in sex. If you are going to spay or neuter your puppy, this is the time to speak to your veterinarian.

Behavior: Challenging and Ranking

You know that age kids cross their arms, stomp their feet and say “No!”? This is that age for your pup. Be prepared for him to cross boundaries and ignore directions. His urge to disobey and attempt to command isn't to make you mad. He’s testing his limits to better understand his place in the pack – your pack. So, don't take it personally. Instead, when he says, “I don't have to listen to you,” calmly remind him, “Oh yes you do.” Begin basic puppy training the moment he enters your home and make sure you always reward good behavior.

Nutrition: Keep Feeding Puppy Food!

Puppies have unique nutritional needs and during certain times of growth will require higher levels of many nutrients than adult dogs require. So be sure to feed a food that’s made especially for puppies. Keep feeding your puppy a specially formulated puppy food during this important phase to help his bones, organs, muscles, and joints to grow.

6 - 12 Months

The “Teen Years”

Keep your hand tight on that leash! Your pup is getting ready to sprint to the finish line. If she’s a smaller breed, she’ll hit adulthood around age one. Larger breeds will reach full adult maturity closer to age two. Get ready, these last 6-18 months are going to mix a lot of fun with a new set of challenges. Your puppy will become more mature and gain some independence, which will let you get out and do more with her. But don’t forget that she’s still a puppy and needs to follow the rules.

Development & Health: Final Growth

By now there's a good chance your pup has grown close to her full height. Over the next 6-18 months, she'll finish filling out her frame, so make sure you continue to feed her properly to give her all the nutrients she needs. And don't be fooled, while she might look fully grown, inside she still has lots of growing up to do.

Behavior: Energy Burst

Now that your pup has a near full size body, she’s likely to explode with energy. Playtime will be especially fun, but in this new sprightliness she might forget some of her training. She’ll spend lots of time exploring and will easily get distracted. So, don't be shy about reinforcing some of the rules or even making new ones. If your puppy starts causing trouble, try directing her energy toward healthy outlets like fun activities or socializing with other pups.

Nutrition: Keep Feeding Puppy Food!

Continue to feed your pup a specially formulated puppy food until she becomes an adult dog (12 months for most puppies, 24 months for large breeds). Puppy food contains nutrients essential for your puppy’s development, including some ingredients, like DHA, which are not commonly found in leading adult dog foods.

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12+ Months

Puppyhood Graduation

At about the one year mark — two years for large breeds — your puppy’s bones and joints are full size; and his muscles, internal organs, immune system, and cognitive skills are fully developed. At this point, your dog has reached adulthood and no longer needs the extra nutrients. Thus, he or she can begin eating a complete and balanced adult dog food. 

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How Breed Size Affects Puppy Development

While the general rule of thumb is that dogs less that 12 months of age are considered puppies, a puppy’s size can impact whether or not they reach adult maturity before one year of age or reach full maturity closer to 24 months of age.  

Every dog is different. But the following guidelines can help give you a starting point to know when to ask your vet if you can start transitioning off of puppy food and begin to feed adult dog food.

Extra Small Breeds < 8 lbs 9-11 months
Small Breeds 8-20 lbs 12 months
Medium Breeds 21-50 lbs 12 months
Large Breeds 51-130 lbs 18-24 months
Giant Breeds > 130 lbs 24 months

Many dog owners make the mistake of switching their puppy over to adult dog food too soon — before their body has finished growing. It is important to feed your dog food that is formulated for puppy growth and development up to the point that he or she reaches full adult maturity.  If you have specific questions regarding your dog’s development, be sure to consult your veterinarian.