Key takeaways
- Dogs do have a collar bone, but it is very small and embedded in the brachiocephalicus muscle.
- The real bone in the dog does not attach to the skeleton and offers minimal stability, unlike our solid clavicle.
- The shoulder blades and upper arms must be free to move so the dog can run at full speed while absorbing the shock of forceful contact with another animal, or simply the ground.
- The small clavicle is also of little use for attaching muscles or protecting soft tissues.
One of the things that surprised me was when I first started volunteering at a local animal shelter and got to see up close and personal some of the dogs’ skeletons and musculature is that dogs do not have those prominent collar bones humans have. If you feel along your own shoulders there’s a hard, horizontal bone connecting your shoulder to your sternum. Do the same with a dog and you won’t experience anything close to it. This distinction prompted me to wonder: do dogs have a collar bone at all, or are they boneless in that area?
The short answer is that yes, Dogs have a clavicle, but it’s one-dimensional at best and doesn’t anchor the shoulder; rather, it is encased in the brachiocephalicus muscle. This distinction is made more obvious in the post Dog vs Human Collar Bones: Key Anatomical Differences where it’s clear that our robust, S-shaped clavicle aside comparing to the dog’s–useless at best–vestigial remnant was all they needed to liberate their range of movement.
What accounts for this decline is evolutionary? As we discuss in Why Don’t Dogs Have a traditional Collar Bone?, wolves and other early canids were pursuit hunters and a fixed clavicle would have impeded their gallop. Loose it enabled floating shoulders and long, ground-covering gaits. But vestigial does not mean worthless. Is the Dog Clavicle Vestigial or Functional? asks: how such a small bone perpetuates subtle support in breeds muscles and protects nerves, even if it no longer supports the shoulder joint. For dog owners, placement matters. The How? book Where Is a Dog’s Collar Bone Located? explains why you can’t feel a bone under the skin and why collars or harnesses rest right on soft tissue, urging us to pick one thoughtfully.
Dogs vs humans: A comparison of anatomy
Humans need a sturdy collarbone to support this girdle, which moves forces from the arm to the torso. Dogs, on the other hand, developed as fast runners and hunters. Instead of a bony strut, they have tungsten-thin implant rods with as little as 5 percent hard bone for support, and in some cases just a sliver anchored in muscle. This isn’t a minor difference. It changes the way front limbs behave.
| Feature | Humans (clavicle) | Dogs (clavicle) |
| Size & shape | Long, horizontal bone that spans from sternum to scapula | Tiny remnant (<2 cm) embedded in shoulder muscle |
| Attachment | Forms true joints with sternum and scapula | Not attached to other bones; suspended in muscle |
| Function | Provides rigid support for lifting, pushing, climbing | Mainly serves as a muscle anchor; no rigid support |
| Effect on movement | Limits stride length but allows forceful arm motions | Allows scapula to “float,” enabling long, flexible strides |
| Visibility/Palpability | Easily felt and seen under the skin | Not visible or palpable; detected on imaging only |
The dog’s specialization also goes beyond the clavicle. Unlike humans, dogs have separate shoulder bones their clavicles are not fixed to the rest of the skeleton. This floating shoulder enhances stride length and running/jumping flexibility. As I’ve discovered when playing fetch with my spirited border collie, that free‑flowing shoulder means he can stretch his legs far beyond anything we could ever achieve.
Why the bone in a dog’s neck is so puny
Dogs are members of the order Carnivora, and the majority of carnivora either have a reduced clavicle or no clavicle. The answer is function: These animals are built to run and pounce, not climb or handle objects. A stiff bone connecting the shoulder to the rib cage would block the stride, transmitting jarring forces to the spine. When the clavicle was diminished, tetra pods acquired:
- Longer stride: Without a bone to connect the scapula to the rib cage, the shoulder blade can move, enabling longer steps with the forelegs than and even further backwards.( source )
- More shock absorption: As muscles and connective tissues work together like springs, they dampen the force of each stride something I’ve seen when my dog lands after jumping for a Frisbee.
- Slim bone up front: Less mass, less inertia; quicker acceleration and maneuverability.
I once spent time studying the physiology of dogs and watched greyhounds run in slow motion. Their shoulders appeared to float back and forth with each stride, and it was obvious how the lack of a collarbone gives them the smooth, ground‑covering gallop that all sight hounds are so well known for.
Where the canine clavicle hides
Do dogs have a collarbone at all and if so where is it? Anatomical and veterinary reference texts report that the clavicle of a dog is a rudimentary bone in the brachiocephalicus muscle ( source ). It is a large muscle that extends from the base of the skull to the arm (humerus). Hidden away in it is the little clavicl everyone 1–2 cm long, generally. It consists of cartilage or thin bone, and connects to neither the sternum nor the scapula. You can’t feel it beneath the dog’s fur, since it is buried in muscle and connective tissue.
In reality, the only time I’ve seen a dog’s clavicle is on X-ray. During an internship at a veterinary clinic, I observed a radiologist pointing to a faint line in the shoulder a piece of ossified tendon. In some dogs you can’t even see it; in others it looks like a tiny spot. Frequently it remains without becoming ossified.
What purpose does the small clavicle serve
From an evolutionary standpoint, the dog’s clavicle is vestigial: a holdover of something that served a bigger purpose in the past. Early mammalian ancestors that climbed or manipulated objects required a robust clavicle. When wolves and other canids became pursuit hunters, the clavicle got smaller.
Yet “vestigial” doesn’t mean useless. The clinical observation is supported by the fact that, in dogs, the clavicle has a limited role as a muscle attachment in the shoulder. It helps to steady the brachiocephalicus and can prevent nerves or vessels from being damaged as they pass in front of the shoulder. When I massage my two working dogs on their shoulders after a long, hilly walk, I can feel the way that those muscles line up and pulse together; some small internal anchor probably helps to control that alignment.
The clavicle in dogs to read about the canine clavicle made me anew to appreciate how beautifully dogs are constructed for speed and agility. So the next time your dog runs across a field, just know that missing clavicle is a reason they can move so fluidly.
