When Do Dogs Stop Growing?

Picture of a dog with a measuring tape, how big will it grow?

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How big will my puppy grow?” It’s a question pet owners frequently ask veterinarians like myself. While it can be difficult to give an exact estimate of a puppy’s adult weight, some factors can help give an idea of what to expect. Read on to learn more about what affects growth in puppies, how you can help facilitate healthy growth, and when you may expect your puppy to stop growing.

Factors That Can Influence a Puppy’s Adult Weight

Puppies are individuals with unique genetics and environmental factors that can influence their eventual adult weight. Let’s take a look at a few factors that can influence a puppy’s adult weight.


If you know your dog’s breed, you can often accurately predict how big they will grow. The AKC (American Kennel Club) lists breed standards that describe the average size of adult dogs of each breed. This puppy weight calculator can also be used to estimate how big puppies of specific breeds will grow based on their current age and weight. However, estimating the expected size of a mixed-breed dog may be more difficult, as each dog’s size can vary depending on which breed’s genes are expressed more dominantly.1

Size of the Parents

Another predictor of adult size is the size of the puppy’s parents. Reputable dog breeders often have both parents on the premises; you may ask to see them to determine how big one of their puppies might be. This can also be tricky for mixed-breed dogs due to genetic variation (as described previously), or for dogs where one or both parents are not known.


Male dogs generally grow larger than female dogs of the same breed, though this is not always the case and the difference may not be significant.2

Genetic Diseases or Defects

Puppies can be born with genetic diseases or defects that affect their adult size. Disorders causing stunted growth in puppies are uncommon and include liver shunts, heart defects, dwarfism, immune system deficiencies, and muscular dystrophy, among others.345

Parasites or Illnesses Contracted During Growth

Puppies that are born with or contract intestinal parasites after birth commonly have poor growth. Intestinal worms may ingest the puppy’s blood, thereby stealing essential nutrients. Parasites may also damage the intestines, preventing normal absorption of nutrients from the food. Lastly, parasites can cause chronic vomiting and diarrhea; nutrients are lost through these as well.6 Because puppies commonly have intestinal parasites, they will often receive a prophylactic deworming medication during their first few routine veterinary visits. If you notice worms in your puppy’s stool, or if your puppy has chronic vomiting or diarrhea, they should be evaluated by a veterinarian as soon as possible.

Nutrition While Growing

Proper nutrition during growth is essential for puppies to become healthy adults. Puppies require different amounts of nutrients than adult dogs, so it is important to give them a food specifically formulated for puppies, rather than food labeled for adult dogs only.7 Home-cooked diets are not recommended unless owners consult with a veterinary nutritionist to ensure all of the puppy’s nutrient needs are met. More information regarding nutritional requirements and feeding guidelines for growing puppies can be found below.

What and How Should I Feed My Puppy To Ensure Normal Growth?

As previously described, puppies have specific nutrient requirements for normal growth that differ from those of adult dogs. For example, puppies need more protein, fat, calcium, and phosphorus than adults for normal development.89 AAFCO (the Association of American Feed Control Officials) is an organization that publishes annual guidelines describing which nutrients dog foods should contain, and at what concentrations, depending on a dog’s life stage. Puppies should receive a food that meets these AAFCO guidelines to ensure adequate nutrition. A nutritional adequacy statement, which says whether a food meets AAFCO guidelines, can usually be found on the back of the bag in the nutritional information section. Puppies should receive foods that are listed as adequate for growth and reproduction, or for all life stages.

Once you have selected a food meeting your puppy’s nutrient requirements, it is also important to feed the correct amount of food to prevent a puppy from becoming overweight or underweight.10 You should measure your puppy’s food allotment in terms of 8 oz cups to have an accurate estimate of how much the puppy is being fed per day. Feeding guidelines on the back of the dog food bag can be used as a rough guide, but these usually over-estimate the amount of food that a puppy needs. This website provides a formula that you can use to accurately calculate how many calories your puppy should be eating per day. The number of calories in an 8 oz cup of food is usually listed on the back of the dog food bag. It is also a good idea to talk to your vet about how much you should feed as your puppy grows.

How Can I Monitor My Puppy’s Growth?

Ideally, pet owners should regularly weigh their puppies to monitor their growth and ensure they are gaining weight appropriately. You can use a bathroom scale to do this at home: weigh yourself first, and then weigh yourself while holding your puppy. The difference between the two weights is your puppy’s weight. You may weigh your puppy on a weekly to monthly basis, and may even continue this into adulthood to ensure your dog maintains a healthy weight. This body condition score guide can be used for adult dogs to determine whether they are overweight or underweight.

So, When Can I Expect My Puppy To Stop Growing?

As a general rule, small dogs stop growing sooner than large dogs. Toy and small dogs may grow until they are 6-9 months old, medium to large dogs may grow until they are 12-16 months old, and giant breed dogs can continue to grow until they are 24 months old.

Get more information about the growth of your dog with our series of growth charts by breed:


Article Sources

Pet News Daily uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Simpson RJ, Simpson KJ, VanKavage L. Rethinking dog breed identification in veterinary practice. JAVMA. 2012;241(9):1163-1166. doi:10.2460/javma.241.9.1163
  2. Conklin LM. How male and female dogs are different. Rd.com. Published July 7, 2020. Updated March 16, 2022. Accessed April 4, 2022.
  3. Tou SP. Congenital and inherited disorders of the cardiovascular system in dogs. Merckvetmanual.com. Updated October 2020. Accessed April 4, 2022.
  4. Greco DS. Juvenile-onset panhypopituitarism in dogs. Merckvetmanual.com. Updated October 2020. Accessed April 4, 2022.
  5. Kornegay JN, Bogan JR, Bogan DJ, et al. Canine models of Duchenne muscular dystrophy and their use in therapeutic strategiesMamm Genome. 2012;23(1-2):85-108. doi:10.1007/s00335-011-9382-y
  6. Peregrine AS. Gastrointestinal parasites of dogs. Merckvetmanual.com. Updated October 2020. Accessed April 4, 2022.
  7. American Animal Hospital Association. Age-specific and breed-specific diets. Aaha.org. Accessed April 4, 2022.
  8. Buzhardt L. Nutritional requirements of large and giant breed puppies. Vcahospitals.com. Accessed April 4, 2022.
  9. Royal Canin. When does my puppy become an adult dog? Royalcanin.com. Accessed April 4, 2022.
  10. Kearl M. Healthy weight gain for puppies. Akc.org. Published January 21, 2020. Accessed April 4, 2022.
Dr. Jennifer Masucci
Dr. Jennifer Masucci, VMD is a graduate of the University of Pennsylvania School of Veterinary Medicine. Through multiple years of working as a small animal general practitioner, Dr. Masucci is particularly well-versed in canine and feline medicine. Dr. Masucci is passionate about educating pet owners, so that they can offer the best care to their furry companions.