Depending on their breed and size, your dog reaches full physical maturity anywhere between 6 to 24 months. You can expect your dog to reach their adult height and shape by about 12 months, though this can vary:
- Small/medium dogs: Between 6 to 8 months
- Large dogs: Between 12 to 18 months
- Giant dogs: Up to 24 months
Once they reach their adult size, your dog continues to grow in ways less noticeable to the naked eye. Rather than height and length, your dog’s physical development shifts to muscle and fat growth. Typically, the larger the dog, the slower the development.
What should you expect while your puppy grows?
Teething. Your puppy’s teeth start emerging somewhere around the two week mark, long before they’re able to come home. The tooth fairy becomes a regular visitor while your dog is between 3 to 6 months old. At the end of that journey, your dog should have a full set of adult teeth.
While your dog is teething, they’re going to want to chew. Frozen toys and treats can help soothe sore and achy gums. Provide lots of tasty chews and bones to motivate them to gnaw on the appropriate objects and not, say, your furniture or hands.
Adolescence. Your dog can be classified as an adolescent when they turn 6 months, though the precise start varies between individuals and breeds. Small breed puppies mature earlier and can end adolescence around the 18 month mark; large breed or giant puppies may not start until 9 or 10 months and may not enter adulthood until they’re about 2 years old.
During adolescence, your dog may start testing boundaries and regressing on training. It is very, very common for adolescent dogs to regress on house training–if you’re dealing with this, don’t worry, you’re not alone. Lower the criteria, remain consistent and persistent, and your dog eventually emerges as a well-behaved adult.
Growth plates. Sometimes it seems like puppies double in size overnight. A lot is happening under the surface–and a big part of that is the biological processes happening in your dog’s growth plates. Located at the ends of long bones in your dog’s skeletal structure, growth plates are filled with cells that divide amongst themselves until they fill the available space, helping your dog’s bones grow longer and denser.
Because of this, hard physical activity is not recommended until your dog’s growth plates close, which happens around the 12 month mark. As always, keep in mind that the larger the dog, the longer the growth plates take to close.
Does neuter/spay affect my dog's health?
Most puppies get neutered between 6 to 24 months to reduce cancer risks and prevent accidental litters. Talk to your vet to determine the best timing for your pet.
Owners of large breed dogs may prefer to wait longer. Gonadal hormones–estrogen, testosterone, and progesterone–influence growth. Early spay and neuter is believed to delay the closure of the growth plates, resulting in taller dogs. However, waiting until skeletal maturity can increase the risk of developing cancer later in life. As such, the precise timing on when to spay or neuter your dog is a personal decision that you should discuss with your vet.
Neutered/spayed dogs do not grow at different rates than unfixed dogs, nor are they more likely to gain weight. In terms of physical and behavioral development, there is no significant difference between puppies neutered at 7 weeks and at 7 months.
How big will my dog get?
Purebred dogs are easier to predict, as their breeder should be striving to achieve a consistent size and appearance. Mixed breed dogs can be all over the map; the more different breeds they have in their DNA, the more random the outcome can be. Even two puppies from the same litter can look like wildly different adults.
One very broad rule of thumb is that your dog’s weight at 6 months is approximately 60 percent of their adult weight. Like any living creature, your dog may not grow in a consistent, linear fashion, so don’t put too much stock into this, especially if you’re raising a mixed breed dog.
An extra consideration for the owners of large breed puppies is nutrient intake. There can definitely be too much of a good thing! Over supplementation of nutrients can lead to skeletal conditions. In general, puppies need to grow at an even rate all over their bodies to develop proper skeletal structure.
If you’re concerned about your ability to handle a large, unruly adult dog, invest early on in training. Gentle Beast offers virtual workshops led by certified behavior consultant Alex Sessa who walks you step-by-step through training your dog to walk nicely on the leash, develop impulse control, and practice bite inhibition. Of course, every dog has to start with the basics, so check out the full course catalog here and start building a personalized training plan for your needs.
What should my puppy be learning?
For the first few weeks, your priority is socialization. Focus on exposing your puppy to as many different sights, sounds, people, and environments as possible. Use a puppy socialization checklist to make sure you’re covering all your bases. During this time, start your puppy on basic house training and crate training.
Your puppy can learn foundational behaviors like Sit, Down, Place, etc. at any age. The earlier they learn, the more ingrained those behaviors can become, but the old saying is definitely untrue: old dogs can always learn new tricks.
During adolescence, your puppy will likely need to focus on reviewing those skills and work on developing consistency. If they’ve already started working on impulse control exercises, great–and if not, this is the perfect time to introduce them into your dog’s repertoire.
And finally, the big one: recall. Can your dog come to you while off-leash? While your dog is a soft little puppy, they naturally want to stick close to you–after all, you’re their parent and teacher and packmate. But as your dog becomes an adult, they’re more confident about leaving your side, and the call of the wild can get pretty strong. Training recall is of paramount importance.
During the first few years of their life, your puppy has a lot to learn. And if this is your first dog, you might be learning alongside them. Gentle Beast offers online workshops and video modules on different training concepts, behavior cues, and need-to-know information for humans, all led by certified trainer and behavior consultant Alex Sessa.