Your puppy’s full size—and when he reaches it—can depend on genetics. And though heredity can offer a peek into a dog’s eventual size, even littermates can be considerably different—so don’t base your puppy’s growth on his siblings’. Instead, ensure your puppy is getting the nutrition and care he needs and consider these facts about growing dogs.
At what age are puppies full grown?
The age at which a dog reaches full size depends on the type of dog. Small breeds mature faster than large breeds, both physically and mentally. Large dogs take longer to reach their final height and weight, and their puppy-like behavior lasts longer.
Though a puppy growth chart may help your veterinarian estimate size, it may not be accurate for every dog. Each dog is an individual, growing and developing at his own rate. Even purebred dogs can end up outside the breed standard. Female dogs tend to be smaller than males of the same breed, but growth happens at the same rate. If your puppy is healthy, but not as big as you would have expected, it is likely no cause for concern.
Puppy Growth by Breed Size
|Breed Size||Full-Grown Age (Height and Weight)|
|Toy and Small (Chihuahua, Papillon, terriers)||Between 8 and 12 months|
|Medium (Springer Spaniel, Border Collie)||Between 12 and 15 months|
|Large (Labrador Retriever, German Shorthaired Pointer)||Between 18 and 24 months|
|Giant (Great Dane, Newfoundland)||Up to 3 years|
How do puppies grow?
Puppies go through numerous growth spurts during their first months. What may have started as a one-pound ball of fur quickly packs on the pounds and stretches upward. Growth plates—flexible areas in the bone where new tissue forms and calcifies—grow as a puppy develops. Dogs reach their final height when that tissue hardens and becomes bone, closing the growth plates. They continue to fill out after they’ve reached their adult height, reaching their ideal weight shortly after.
While a dog may look like an adult, you may still have rambunctious puppy behaviors to contend with. Socializing and obedience training are key during adolescence, and can make all the difference for breeds that live in a state of perpetual puppyhood. Because rapid growth and bone development happen throughout the first year, strenuous exercise can damage joints and growth plates. Vigorous activity such as agility training should wait until puppies reach adulthood.
Do big paws mean a big dog?
The assumption that a puppy will grow into his big paws has some truth behind it, but it’s by no means a foolproof way to determine a dog’s full size. Big dogs often start with paws that seem disproportionately large. Tall dogs need big feet to support them, so diminutive paws may hint at a smaller dog. But large feet do not necessarily mean your puppy will be massive. Most puppies go through a stage when none of their body parts seem to fit, and only time will tell.
You may be able to estimate your puppy’s adult size by doubling his weight at 16 weeks, but it’s an approximation. Another formula to calculate adult weight is to divide his current weight by his age in weeks, then multiply by 52. While neither method is infallible, they provide a general idea.
Does my puppy need supplements to grow?
Feeding your dog a high-quality, veterinarian-recommended diet formulated for his needs is the best way to ensure proper growth. Adding supplements or feeding more than is recommended may set up your puppy for trouble down the road. If a large breed dog grows too quickly, he can experience joint and bone problems. While your canine companion may continue to gain weight, a Body Condition Score (BCS) determines whether a dog is overweight, too thin, or just right. Your veterinarian can recommend the right diet to suit your dog’s specific needs.
You know he won’t be tiny forever, but when will that roly-poly Lab puppy be full-grown? And how can you tell how big your puppy will be as an adult? Though it may seem the chewing stage may never end, puppies grow up quickly—just how quickly depends on your dog’s adult size. A small breed often reaches maturity by one, while large dogs may not be fully grown until their second birthday. Keep a growing puppy busy with plenty of fun and games, and teach some basic obedience before you realize he’s big enough to take you for a walk.