The Dog Skeleton: Anatomy, Bones and Why It Matters for Behaviour
Updated: Nov 1
Most of us only think about our dog's skeleton when something goes wrong, like a limp after a long walk or a dog who suddenly won't jump into the car. But the way your dog's bones fit together shapes how they move, how they sit and lie down, and even how patient they feel. After years in agility, I'm always asking whether a "behaviour problem" might really be a body problem, and knowing a little about the dog skeleton makes that much easier to spot.
THE SHORT ANSWER
A dog's skeleton has around 320 bones, give or take depending on the length of the tail. It's made up of the skull, a long spine running from the neck to the tip of the tail, 13 pairs of ribs, and four legs. Dogs have no proper collarbone, so their front legs are held on by muscle rather than a bony joint, and they walk on their toes. The skeleton matters for behaviour because pain in the spine, hips or joints often shows up as grumpiness, reluctance or reactivity before it shows up as a limp.
How many bones does a dog have?
Most dogs have between 319 and 321 bones. The number changes from dog to dog, mainly because of the tail. A Labrador with a long tail has more tail bones than a breed born with a short or bobbed tail, and some dogs have extra dewclaws on their back legs too.
For comparison, an adult human has 206 bones. Dogs have more mostly because of their long tail and their extra vertebrae.
Dog skeleton anatomy: the main parts
It helps to think of the dog skeleton in five sections, because each one plays its own part in how your dog moves, rests and feels:
The skull: protects the brain, eyes and inner ear, and holds the jaw and teeth. Skull shape varies more in dogs than in almost any other animal, from the long, narrow head of a Greyhound to the short, wide face of a Pug.
The spine: 7 neck vertebrae, 13 in the chest, 7 in the lower back, 3 fused into the sacrum over the hips, and anywhere from about 6 to 23 in the tail.
The ribcage: 13 pairs of ribs protecting the heart and lungs.
The front legs: shoulder blade, upper arm, two forearm bones, wrist, and the paw. Dogs carry roughly 60% of their weight on the front end.
The back legs: pelvis, thigh bone, kneecap, two shin bones, the hock (which works like our ankle) and the paw.
Dog bone structure: what makes it different from ours
No collarbone
Dogs don't have a working collarbone. At most there's a tiny scrap of bone buried in the muscle. That means the front legs aren't locked to the body by a joint, they're held on by muscles and tissue. It gives dogs a longer stride and lets the shoulder blade glide as they run, but it also means the muscles around the shoulders work hard all day. Tight, sore shoulder muscles are common in dogs who pull on the lead or do a lot of fast turning.
Walking on their toes
Dogs are digitigrade, which means they stand on their toes rather than flat feet. What looks like a backwards knee on the back leg is actually the hock, the equivalent of our ankle. This makes dogs fast and springy, and it's why sore toes, long nails or a split pad can change the way a dog stands and moves.
A spine built to flex
A running dog's spine bends and stretches with every stride, a bit like a spring. That's brilliant for speed, but it means stiffness anywhere along the back affects the whole dog. A dog with a sore back often moves stiffly, avoids stairs or curls up in an unusual way.
Why your dog's skeleton matters for behaviour
When a dog is sore, their patience drops. A sore hip or back can turn a happy, easy-going dog into one who grumbles when moved off the sofa, snaps when brushed, or struggles to cope with other dogs on a walk. The behaviour change is often the first sign, long before a limp.
Pain doesn't always look like pain in a dog. These are some of the common signs that what looks like a "training problem" might actually be a sore body:
refusing to sit squarely, or sitting with one leg flopped out
slow to lie down, or circling many times before settling
not wanting to jump in the car or onto the sofa any more
growling or moving away when touched near the back, hips or neck
pulling more on the lead, or a sudden change in how they walk
seeming more reactive to dogs, noises or people than usual
If you notice any of these, start with your vet. A physiotherapist or hydrotherapist can help a great deal once your vet has checked your dog over. Read how hip dysplasia affects training and behaviour and arthritis signs in older dogs.
Puppies: a skeleton still growing
A puppy's bones grow from soft areas near the ends called growth plates. These don't close until somewhere between about 8 and 18 months, later in big and giant breeds. Until then, lots of repetitive high-impact exercise, like long runs, endless ball chasing or jumping from height, puts strain on joints that are still forming.
That doesn't mean wrapping your puppy in cotton wool. Free play, sniffing, gentle walks on different surfaces and short training games are all great. It's the repetitive pounding that's worth keeping to a minimum. Read puppy growth plates and safe exercise.
Helping your dog's body stay comfortable
Body awareness exercises help dogs of every age use their skeleton well. Walking slowly over poles on the ground, stepping onto a low platform, backing up a few steps and turning in small circles all build balance and strength. Read canine proprioception and body awareness.
Keeping your dog slim is one of the kindest things you can do for their bones. Every extra kilo puts more load on the joints. Good grip at home helps too, so rugs on slippery floors, and trimmed nails and fur between the pads.
RENEE'S TIP
Watch your dog lie down tonight. A comfortable dog usually folds down smoothly and lies evenly. If your dog hovers, drops heavily, always lies on the same side or keeps getting up and resettling, it's worth mentioning at your next vet visit, even if they seem fine on walks.
QUICK CHECK
ā Dogs have around 320 bones, mostly depending on tail length
ā No working collarbone, so the front legs are held on by muscle
ā Dogs walk on their toes, and the hock is their ankle
ā Pain often shows up as behaviour change before a limp
ā Protect growing joints and keep your dog slim
ONE-TO-ONE HELP
Help with a dog whose behaviour has changed
If your dog has become grumpy, reactive or reluctant and your vet has ruled out pain, I can help you work out what's going on and build a plan in an online Dog Behaviour Consultation from wherever you are.
Online on Teams, wherever you are. 30 or 60 minutes.
FAQs
How many bones does a dog have?
Usually between 319 and 321. The exact number depends mainly on how long the tail is, and on whether the dog has extra dewclaws.
Do dogs have a collarbone?
Not a working one. Their front legs are attached to the body by muscle, which gives them a longer stride.
What is the dog's ankle called?
The hock. It's the joint on the back leg that looks like a backwards knee.
When do a puppy's growth plates close?
Usually between about 8 and 18 months. Large and giant breeds close later than small breeds.
Can bone or joint pain change a dog's behaviour?
Yes. Sore dogs often become less patient, more reactive or reluctant to be handled, sometimes before they ever limp.
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.
