When Do Puppies Stop Growing? (Breed-by-Breed Timeline)

How Puppy Growth Actually Works

Puppy growth isn't a steady, predictable curve. It happens in two overlapping phases that finish at different times, which is why the question "when do puppies stop growing?" doesn't have a single answer — it depends on which kind of growing you mean.

The first phase is skeletal growth, driven by structures called growth plates. These are bands of soft cartilage at the ends of long bones. While they're open, new bone tissue forms there and the bone gets longer. Once the growth plates close — converting fully into hard bone — the puppy can't get any taller. Closure happens earlier in small breeds and later in large ones, which is why a Chihuahua reaches full height in under a year while a Great Dane needs two.

The second phase is muscle and fat development. Even after a dog stops getting taller, the body keeps filling out, gaining muscle mass, broadening through the chest, and developing the adult silhouette. This continues for 3–12 months after height stops, again depending on breed size.

When most owners ask "is my puppy done growing?" they're usually noticing one of these phases ending — height plateauing, or weight finally stabilizing. Both matter, and they happen at different times.

When Puppies Stop Growing by Breed Size

The single biggest factor in growth timeline is adult size. Bigger dogs grow longer, full stop. Here's the breakdown:

Small Breeds (under 25 lb at maturity)

Examples: Chihuahua, Yorkshire Terrier, Pomeranian, Toy Poodle, Maltese, Shih Tzu, Pug, Miniature Dachshund, Boston Terrier

Small breeds finish growing in height around 9 to 12 months. Weight typically stabilizes by 12 months. Many small dogs reach 90% of adult weight by 7–8 months, then trickle in the final 10% slowly. They're the earliest to mature and the easiest to predict — by their first birthday, what you see is essentially what you get.

Medium Breeds (25–50 lb at maturity)

Examples: Beagle, Cocker Spaniel, Border Collie, Australian Shepherd, Standard Schnauzer, Bulldog, Whippet, Shetland Sheepdog

Medium breeds reach full height by 12 to 15 months. Weight and muscle development continue until around 16–18 months. Most medium-breed puppies look like adults at one year but haven't quite filled out — the chest deepens and shoulders broaden through their second year.

Large Breeds (50–100 lb at maturity)

Examples: Labrador Retriever, Golden Retriever, German Shepherd, Boxer, Doberman Pinscher, Rhodesian Ridgeback, Standard Poodle, Vizsla

Large breeds finish height growth between 15 and 18 months. Weight and muscle mass keep developing until roughly 24 months. Owners of Labradors and Goldens often notice their dog looks gangly and "all legs" at one year, then fills out into a sturdier adult shape over the following year.

Giant Breeds (over 100 lb at maturity)

Examples: Great Dane, Mastiff, Saint Bernard, Newfoundland, Irish Wolfhound, Great Pyrenees, Bernese Mountain Dog, Leonberger

Giant breeds are the latest to finish, with height growth continuing until 18 to 24 months. Full muscle development takes until 2.5–3 years in some cases. A Great Dane at 18 months may still look slightly leggy and proportionally young, even though it weighs 130 lb. Patience is required — and so is careful feeding, since pushing growth too fast in giants causes joint problems that don't show up until later in life.

Signs Your Puppy Has Stopped Growing

You don't need a vet to tell you growth has finished. The signs are visible if you know what to look for.

Height plateaus. If you measure your dog at the shoulder (the withers) once a month, you'll see consistent monthly increases during active growth — sometimes half an inch or more in large breeds. When growth ends, those measurements stop changing. Three consecutive monthly measurements that match means height is done.

Paws are no longer disproportionately large. Puppies have famously oversized paws because the foot bones are among the last to finish hardening. When the paws start looking proportional to the leg, you're near the end of skeletal growth.

Body proportions look adult. Puppies have characteristically long legs relative to body length and a slightly "leggy" appearance. As growth completes, the body deepens through the chest and the proportions shift toward the breed's adult silhouette.

Weight stabilizes. Track weight monthly. When weight gain slows to almost nothing for two consecutive months and the dog isn't underweight, growth has finished. Note: an adult dog may still gain 5–10% of its weight as muscle through its second year, so small increases don't necessarily mean growth.

Loss of "puppy fluff." The soft, dense puppy coat is replaced by the adult coat between 6–18 months depending on breed. While not a perfect indicator, dogs with fully adult coats are typically near the end of growth.

The most reliable confirmation is an X-ray showing closed growth plates. Vets sometimes do this for sporting and working dogs, since it's the medical answer to "is this dog skeletally mature enough to start agility / weight pulling / serious training?" For pet owners, the visual signs above are usually enough.

💡 Curious where your puppy is in the growth curve right now? Try our Puppy Weight Calculator — enter your puppy's current weight and age and we'll predict their adult size based on breed-specific growth patterns.

Why Some Puppies Grow Differently

Two puppies of the same breed can finish growing months apart. Several factors influence the timeline.

Sex. Male puppies are usually larger and finish growing slightly later than females in the same breed — typically by 1–3 months. This is a hormonal difference: testosterone influences both peak size and how long the growth window stays open.

Spay/neuter timing. This one is more contentious than most owners realize. Removing sex hormones early — especially before the growth plates close — actually causes the plates to stay open longer than they would have. The puppy ends up slightly taller and longer-limbed than they would have been if left intact, with subtly different proportions. For small breeds the effect is minor. For large and giant breeds, recent veterinary guidance has shifted toward waiting until skeletal maturity (12–18+ months) before spaying or neutering, partly because of orthopedic outcomes. Discuss timing with your vet — there's no single right answer for every breed.

Nutrition. Underfeeding stunts growth; overfeeding accelerates it dangerously, particularly in large and giant breeds where rapid growth correlates with hip dysplasia, elbow dysplasia, and panosteitis. Large-breed puppy formulas are specifically calibrated to slow the growth curve to a healthier rate. They're not a marketing gimmick — the calcium-to-phosphorus ratios genuinely matter for joint development.

Genetics. Within a breed, individual variation is significant. Looking at the parents (especially the mother) is one of the best predictors of how a puppy will turn out. If the dam was on the smaller end of breed standard, the puppy likely will be too.

Health. Parasites, undiagnosed thyroid issues, or chronic illness during the growth window can delay or stunt growth. If your puppy seems significantly behind the typical curve for the breed, it's worth a vet visit.

Common Mistakes Owners Make During Growth

A few things consistently cause problems during the growth window:

Overfeeding large-breed puppies. Faster isn't better. A Lab puppy fed to grow as fast as possible reaches adult size sooner but with worse joints. The veterinary recommendation for large and giant breeds is to keep them on the lean side throughout puppyhood — you should be able to feel ribs easily under a thin layer of fat, and see a defined waist.

Switching to adult food too early for large breeds. Adult food has different calcium and energy levels. Large-breed puppies should stay on large-breed puppy food until at least 12 months, often 18 months for giants.

High-impact exercise too young. Repeated jumping, jogging on hard surfaces, and intensive agility work before the growth plates close can damage developing joints. Free play on soft surfaces is fine. Forced repetitive impact — running on pavement next to a bike, hours of fetch on hard ground — should wait until skeletal maturity.

Worrying about a "growth spurt that ended early." Growth isn't linear. Puppies grow in pulses — fast for a few weeks, then slow, then fast again. A month of slow growth doesn't mean growth has ended. Look at the trend over 3–4 months, not week to week.

What to Do Once Your Puppy Has Stopped Growing

When growth finishes, three things should change:

Switch to adult food. Puppy food is calorie-dense to support growth. Adult dogs on puppy food gain weight. Make the transition over 7–10 days by gradually mixing in increasing amounts of adult food.

Reassess portion sizes. Adult dogs eat less per pound of body weight than puppies. Most owners overfeed for the first few months of adulthood out of habit. Check feeding guidelines on the new food.

Open up exercise. With closed growth plates, your dog can now safely do jogging, hiking, agility, weight-bearing work, and high-impact play that wasn't appropriate during growth. Start gradually — fitness still has to be built — but the orthopedic constraint lifts.

This is also a good moment to schedule the adult wellness exam if you haven't recently. Establishing a baseline weight, dental status, and bloodwork at full maturity gives your vet something to compare against in future years.

Related Questions

Do puppies grow more at night? It's a common saying, but there's no real evidence puppies grow specifically at night. They grow continuously, and growth hormone is released throughout the day in pulses. The "growth at night" idea probably comes from owners noticing their puppy looks bigger after a long sleep — but that's just because they spent several hours not seeing them.

Can I tell how big a mixed-breed puppy will get? Roughly, yes. Look at paw size relative to body, current weight at a known age, and the size of the parents if you have any information about them. A general rule: a puppy reaches about 75% of adult weight by 6 months for medium breeds and by 9–10 months for small breeds. So multiply current weight at that age accordingly. DNA tests can help confirm breed mix and likely adult size if you want more precision.

My puppy seems small for its age — should I worry? Not necessarily. Within-breed variation is significant, and small puppies sometimes catch up later. Check that the puppy is eating well, energetic, has normal stool, and a healthy coat. If those are all good, the dog is probably just on the smaller end. If there are other symptoms — lethargy, poor appetite, slow weight gain, persistent diarrhea — see a vet.

Do neutered dogs grow taller? Slightly, on average, when neutered before growth plates close. The difference is small (often less than half an inch) and usually only matters in specific working or show contexts. For pet dogs, the orthopedic and behavioral considerations of neuter timing matter far more than the height difference.

When do puppies stop teething? Teething is separate from growth and finishes earlier. Most puppies have all their adult teeth by 6–7 months, regardless of breed size. We have a separate guide on the puppy teething timeline.

At what age is my puppy "fully grown" for insurance and registration purposes? Most pet insurance policies and breed registries use 12 months as the cutoff for puppy classification, regardless of whether the dog has actually finished growing. Some giant-breed-specific policies extend this to 18 or 24 months.

🐶 Want to track your puppy's growth precisely? Use the Puppy Weight Calculator to see how their current weight compares to the expected growth curve for their breed.