Puppy Growth Plates: When They Close and Safe Exercise
Updated: 21 hours ago
Your puppy wants to run, jump and chase everything, and it's lovely to watch. But underneath all that bounce, their bones are still growing, and the soft growth plates near the ends of those bones are easy to damage. I've spent a lot of my life around agility dogs, and how a dog is exercised as a puppy really does matter later on. Knowing how growth plates work helps you choose activities that keep your puppy safe now and sound for life.
THE SHORT ANSWER
Growth plates are soft areas of cartilage near the ends of a puppy's long bones, where the bone grows in length. They harden and close as your puppy matures, usually between around 6 and 12 months in small breeds and up to 18 months or more in large and giant breeds. Until then, they're more easily injured. Avoid repeated jumping, long runs, endless ball chasing, slippery floors and lots of stairs. Choose free play on soft ground, short walks, sniffing and gentle training instead.
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What are growth plates in puppies?
Growth plates, also called physes, sit near the ends of the long bones in your puppy's legs. They're made of softer cartilage that lets the bone grow longer. As your puppy matures, this cartilage turns into solid bone and the plates close. Once they've closed, the bones stop growing in length.
Until then, growth plates are the weakest part of the bone. Too much impact, twisting or repetitive strain can damage them, and an injury can lead to uneven growth, a crooked leg or joint problems later in life.
When do puppy growth plates close?
It depends on size and breed:
Small breeds: often by around 6 to 12 months
Medium breeds: around 12 to 14 months
Large breeds, like Labradors and German Shepherds: around 12 to 18 months
Giant breeds: up to 18 to 24 months
Neutering before growth plates close can delay their closure, which is one reason many vets now suggest waiting for large breeds. Talk this through with your vet.
Are puppy bones fragile?
They're not as fragile as glass, but they are softer and more easily injured than adult bones, especially at the growth plates. Most injuries come from falls, jumps from height and repeated strain rather than normal play.
Activities to avoid while growth plates are open
Jumping on and off furniture or out of the car
Lots of stairs, especially running down them
Long runs, jogging or cycling with your puppy
Repetitive ball or frisbee chasing with sharp turns and stops
Running on slippery floors
Jumping in agility or flyball, until your vet says they're ready
Rough play with much bigger dogs
Safe exercise for growing puppies
1. Free play on soft ground
Playing in the garden or on grass lets your puppy stop and rest when they want to.
2. Short, sniffy walks
Short walks with lots of sniffing are kinder on joints than long, fast ones.
3. Training games
Short sessions of sit, down, recall, hand targets and settle work their brain and build skills without strain.
4. Body awareness
Walking slowly over poles on the ground, or stepping onto a low, stable surface, helps your puppy learn where their feet are. Keep it slow and low.
5. Enrichment
Snuffle mats, food toys and chews tire your puppy out without any impact at all.
Signs of a growth plate injury
Speak to your vet if your puppy:
Is limping, or the limp comes and goes
Has a swollen or hot leg or joint
Holds a leg oddly or won't put weight on it
Has a leg that looks bent or a different length
Don't wait to see if it passes. Growth plate injuries do best when they're treated early.
RENEE'S TIP
Teach your puppy to wait to be lifted in and out of the car, and use a ramp or lift them off the sofa. These small habits save a lot of strain on growing joints.
QUICK CHECK
ā Growth plates close between about 6 and 24 months, depending on size
ā Avoid jumping, long runs, stairs and endless ball chasing
ā Choose free play, sniffy walks and training games
ā Use non-slip mats on slippery floors
ā Limping or swelling? See your vet
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FAQs
What are puppy growth plates?
Soft areas of cartilage near the ends of a puppy's long bones, where the bones grow. They harden and close as your puppy matures.
When do puppy growth plates close?
Often by 6 to 12 months in small breeds, 12 to 18 months in large breeds, and up to 24 months in giant breeds.
When do Labrador growth plates close?
Usually somewhere between around 12 and 18 months. Ask your vet if you're unsure before starting high-impact activity.
Are puppy bones fragile?
They're softer and more easily injured than adult bones, especially at the growth plates, so avoid jumps, long runs and repetitive strain.
What exercise is safe for a puppy?
Free play on soft ground, short sniffy walks, training games, slow body awareness work and enrichment like food toys and snuffle mats.
ABOUT THE AUTHOR
Renee Patience Ā· National Dog Trainer of the Year 2025
Founder and head trainer of Paws Academy, with more than 30 years training dogs and a Level 6 Diploma in Applied Canine Behaviour. Renee has competed in agility, obedience and heelwork to music across the UK, including at Crufts and Olympia, has appeared on CBBC, and is the author of the Modern Training Guides and the Modern Breed Handbook series. Pictured with her boxer, Kookie.
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