When Do Small Dogs Stop Growing? A Breed-by-Breed Guide

That tiny ball of fur you brought home at eight weeks old is growing fast — faster than you might expect. Small and toy breed puppies compress a lot of development into a short window, and the question of when it actually ends trips up a lot of owners.

Most small dogs (those that will weigh 14–25 lbs as adults) stop growing between 10 and 12 months. Toy breeds — Chihuahuas, Yorkies, Pomeranians, and other dogs under 14 lbs — grow even faster and are typically done by 8–10 months. That's a completely different timeline from large breeds, which keep growing for 14–18 months. Use our puppy weight calculator to see where your small dog sits on their growth curve right now.

Toy vs. small breed: what the data actually shows

The labels "toy" and "small" aren't just marketing categories — they reflect genuinely different growth patterns. Based on our analysis of 8 million vet-measured weight records from the veterinary growth study by Salt et al. (2017), here's what the data shows for each category.

Toy breeds (adult weight under 14 lbs):

• Reach 99% of adult weight at 36 weeks (~9 months)
• Growth is biologically complete by 40 weeks (~10 months)
• The growth inflection point — when they're gaining weight fastest — happens at just 10 weeks

Small breeds (adult weight 14–25 lbs):

• Reach 99% of adult weight at 46 weeks (~11.5 months)
• Growth is biologically complete by 48 weeks (~12 months)
• Their growth inflection point is a bit later — around 14 weeks

These aren't rough estimates pulled from anecdote. They come from logistic growth models fitted to real vet measurement data — the same methodology described on our growth prediction page. For context, giant breeds don't reach 99% of adult weight until 100 weeks. Small dogs are done growing in less than half that time.

Growth month by month: what to expect at each stage

One thing that surprises new small dog owners is how much of the total growth happens in the first few months — and how fast that growth actually decelerates. Here's the breakdown using exact figures from our veterinary dataset.

8 weeks (when most puppies come home)

At 8 weeks old, a toy breed puppy has already reached 31.0% of their adult weight. For a Chihuahua that will eventually weigh 5 lbs, that's about 1.5 lbs at pickup. Small breed puppies at 8 weeks are at 26.2% — a little behind, but not by much.

3 months (12 weeks)

This is the peak growth phase. Toy puppies are at 44.2% of adult weight and growing faster than at any other point in their lives. Small breed puppies hit 39.4% of adult weight by 12 weeks. If you're not already tracking monthly weights, now is a great time to start.

6 months (24 weeks)

By the six-month mark, a lot of the hard work is done. Toy breed puppies are at 80.5% of their adult weight. Small breed puppies are at 77.2%. You may feel like growth is nearly complete — and for toy breeds, you're right. For small breeds, about a quarter of their total weight gain is still ahead.

9 months (36 weeks)

This is the finish line for most toy breeds. At 36 weeks, toy breed dogs have reached 100% of their modeled adult weight. Small breeds at 36 weeks are at 95.1% — close, but still adding the final few pounds. Most of what you see from here on for small breeds is "filling out" in the chest and shoulders, not height gain.

12 months (52 weeks)

Small breeds that haven't quite finished are largely done by this point. Both toy and small categories reach full biological maturity well before or at the one-year mark. Want to see where your specific dog stands? Run your puppy through our free growth calculator to get a breed-specific weight curve.

Growth timelines for popular small breeds

One of the biggest gaps in most articles on this topic is a breed-by-breed breakdown. Size category timelines give you the average, but your specific breed matters. Here's what our breed dataset shows for eleven popular small and toy breeds.

Breed	Size Category	Adult Weight (Male)	Adult Weight (Female)	Growth Window
Chihuahua	Toy	3–6 lbs	3–6 lbs	~36 weeks
Yorkshire Terrier	Toy	4–7 lbs	4–7 lbs	~40 weeks
Pomeranian	Toy	3–7 lbs	3–7 lbs	~40 weeks
Maltese	Toy	4–7 lbs	4–7 lbs	~40 weeks
Shih Tzu	Toy	9–16 lbs	9–16 lbs	~40 weeks
Pug	Toy	14–18 lbs	14–18 lbs	~40 weeks
French Bulldog	Small	20–28 lbs	16–24 lbs	~48 weeks
Dachshund	Small	16–32 lbs	16–32 lbs	~48 weeks
Miniature Schnauzer	Small	11–20 lbs	11–20 lbs	~44 weeks
Cavalier King Charles Spaniel	Small	13–18 lbs	13–18 lbs	~44 weeks
Boston Terrier	Small	12–25 lbs	12–25 lbs	~48 weeks

A few things stand out from this table. First, Chihuahuas are the fastest-finishing breed listed — their growth window of ~36 weeks is shorter than other toy breeds. Second, French Bulldogs, Dachshunds, and Boston Terriers all sit in the "small" category despite being smaller dogs by most people's standards, and they take measurably longer than true toy breeds to finish growing.

Growth plates in small dogs: what closes, and when

You may have heard the term "growth plates" and wondered what it actually means in practical terms. Growth plates are zones of soft, cartilaginous tissue at the ends of long bones. They're what allow your puppy's skeleton to lengthen, and once they harden — a process called ossification — your dog stops getting taller.

In small and toy breeds, growth plate closure typically happens between 8 and 12 months. Compare that to large breeds, where plates may not close until 14–20 months, and giant breeds, where closure can happen as late as 22 months. The smaller the breed, the faster the plates close — and the smaller the window during which the growth plates are vulnerable to injury.

Why does this matter practically? Because open growth plates are softer and more susceptible to damage than mature bone. A hard fall or an awkward landing on an open growth plate can cause lasting joint problems. With small and toy breeds, that window closes relatively fast — another reason the "puppy phase" feels so short with these dogs.

The only way to definitively confirm that growth plates have closed is a veterinary X-ray. If you're managing an injury, planning to ramp up exercise, or making a spay/neuter timing decision, this is the test to ask for.

Filling out vs. growing taller: why the distinction matters

Most small dog owners notice their puppy's height plateau before their weight does. That's normal — and the two phases have different timelines.

Height growth (skeletal growth) ends when the growth plates close. For toy breeds, this is typically around 8–10 months. For small breeds, it's closer to 10–12 months. After this point, your dog won't get any taller.

Body mass and muscle development continue after height growth ends. This is the "filling out" phase — your dog's chest broadens, muscles develop more definition, and the adult body shape becomes more distinct. For small breeds, this filling-out phase can continue for a few months beyond height maturity.

This distinction matters for a couple of reasons. First, it explains why a Shih Tzu might look physically "done" at 9 months but still be adding muscle and weight through 11 months. Second, it's why weighing your dog monthly is more informative than just eyeballing whether they look grown — the weight curve shows you exactly where they are in the process. You can track this directly using our puppy weight calculator with your dog's current age and weight.

For a deeper look at how these stages map to behavioral development as well as physical growth, our week-by-week puppy growth guide covers the full picture.

What affects how fast a small dog grows

Genetics

Breed and parentage set the upper and lower bounds on your dog's adult size. For purebred small dogs, the parents are your best preview of the adult dog. For mixed breeds, the picture is more complicated — but our puppy weight calculator can help estimate adult size from current weight and age even without knowing the exact breed mix.

Nutrition — getting it right for small breeds

Small and toy breed puppies have different nutritional needs than large breeds. They have faster metabolisms, smaller stomachs, and are prone to hypoglycemia (low blood sugar) if meals are spaced too far apart. Most vets recommend feeding toy breed puppies three to four small meals a day until at least 3–4 months of age.

Unlike large breeds — where overfeeding is a documented risk factor for joint problems — small breeds are more forgiving on the calorie side. That said, obesity in small dogs is common and comes with its own health risks. A body condition score check at each vet visit is the most reliable way to calibrate portions.

Choose a food labeled specifically for small breed puppies if your dog will weigh under 25 lbs as an adult. These formulas have smaller kibble sizes and appropriately dense calorie profiles for a fast metabolism in a small body.

Spay and neuter timing

For large breeds, there's strong evidence that early spay/neuter delays growth plate closure, leading to altered proportions and increased joint risk. For small and toy breeds, the effect is much smaller — the size difference between an early-neutered and an intact small dog is typically minimal.

Most vets still recommend waiting until at least 6 months for toy and small breeds before spaying or neutering. For dogs over 25 lbs, the recommendation has shifted toward waiting longer. Talk to your vet about what makes sense for your specific dog and their health history.

Health factors and parasites

Intestinal parasites are common in puppies and compete for the nutrients your dog needs to grow. A puppy with a heavy worm burden may gain weight more slowly than expected. If your small breed puppy seems to be falling behind on weight gain despite eating well, ask your vet about a fecal test before assuming they just run small.

Conditions like liver shunts (portosystemic shunts) are more common in toy breeds like Yorkies and Maltese and can significantly impair growth. Stunted growth, poor muscle development, and neurological signs after eating are reasons to bring your puppy in for a workup, not just watch and wait.

Signs your small dog is done growing

Rather than guessing based on age alone, here are practical things to watch for:

Weight has been stable for 4–6 weeks. If you've been tracking monthly weights and the number hasn't moved meaningfully in a month and a half, that's your clearest signal. A pound or two of normal daily fluctuation is fine — a consistent plateau over multiple weigh-ins means growth has ended.

Their paws look proportional. Puppies have famously oversized paws relative to their bodies. As they grow into their frame, those paws look less cartoonish and more matched to the rest of the dog. By the time growth ends, everything should look like it belongs together.

Chest has filled out, not just widened. The "filling out" phase is the final chapter. Once your small dog's chest starts looking full and broad rather than narrow and barrel-like, you're usually near the end of active growth.

Coat transitions toward adult texture. Many small breeds (especially Yorkies, Shih Tzus, and Maltese) have noticeably different puppy and adult coats. The transition toward adult fur often tracks roughly with the end of active growth, though the timing varies by breed and individual.

A vet confirms growth plates are closed. This is the definitive test. If you're making decisions around exercise, surgery, or spay/neuter timing, an X-ray of the wrist or knee joint can tell you definitively whether the growth plates have ossified.

When to switch to adult food for small breeds

The food transition timing should follow the growth curve, not the calendar. For toy breeds, you can generally move to adult food around 9–10 months. For small breeds (14–25 lbs), wait until closer to 10–12 months.

The practical test: if your dog's weight has been stable for several weeks and your vet gives the all-clear at the 9- or 12-month visit, that's your signal. Many small breed puppy foods transition gradually rather than all at once — mix the new food in over a week to avoid digestive upset.

One thing to watch: small breed adult foods are often higher in calorie density than puppy foods (because the puppy food was already energy-dense for a fast metabolism). Portion accordingly to avoid the weight creep that's common in small dogs after the first year.

When do small dogs stop growing? FAQ

When do small dogs stop growing?

Most small dogs (14–25 lbs adult weight) finish growing between 10 and 12 months. Toy breeds under 14 lbs grow faster — they typically reach their adult size by 8–10 months. Based on veterinary growth data from Salt et al. (2017), toy breeds reach 99% of adult weight at just 36 weeks and small breeds at 46 weeks.

When do Chihuahuas stop growing?

Chihuahuas typically reach their adult weight of 3–6 lbs by around 9 months (36 weeks). They're one of the fastest-finishing breeds in our dataset, with a growth window of roughly 36 weeks. Some Chihuahuas continue to fill out slightly through 12 months, but height gain and most weight gain are complete well before that.

When do French Bulldogs stop growing?

French Bulldogs stop growing in height around 10–12 months, though many continue to fill out through 12–14 months. As a small breed (not toy), their growth window runs to about 48 weeks. Males typically reach 20–28 lbs and females 16–24 lbs as adults.

How can I tell if my small dog has stopped growing?

The clearest sign is stable weight across several consecutive monthly weigh-ins. Proportional paws, a filled-out chest, and consistent body condition are supporting signals. Your vet can confirm growth plate closure with an X-ray, which is the only definitive test.

Do small dogs grow faster than large dogs?

Yes, considerably faster. Toy breeds finish growing by around 9 months, large breeds take 14–18 months, and giant breeds up to 24 months. Small and toy breeds also hit key milestones sooner — a toy puppy at 12 weeks is already at 44.2% of adult weight, while a large breed puppy at the same age is only at about 27.9%.

When should I switch my small dog from puppy food to adult food?

Toy breeds can typically transition to adult food around 9–10 months. Small breeds (14–25 lbs) can switch closer to 10–12 months. Look for stable weight over several weeks before transitioning, and check with your vet at the 9- or 12-month visit to confirm. Mix new food in gradually over a week to avoid digestive upset.