Dog Anatomy Terminology
Some knowledge of the anatomy of a dog is essential for any person who is interested in studying dogs. This section explains some of the anatomical terms used by dog professionals and Breed Standards when referring to a dog’s basic structure.
Principal Bones of the Legs
As the diagram illustrates, the forequarters are made up of:
- The Scapula or shoulder blade
- The Humerus or upper arm
- The Radius and Ulna, these two bones together forming the dog's foreleg
- The Front Angulation is the angle formed by the Scapula and Humerus.
The hindquarters are made up of:
- The Pelvis
- The Femur, this bone together with the muscles surrounding it forming the upper thigh
- The Tibia and Fibula, these bones together with the muscles surrounding them forming the second thigh.
- The Hind Angulation is the angle formed by the Femur and Tibia (and Fibula).
The important concepts to understand about hindquarter terminology are:
- The Stifle is technically the dog's knee. This is the joint forming the junction between the femur and the tibia and fibula, (above) plus the patella which slides over the joint as the dog moves (please click on picture to enlarge).
- The term 'turn of stifle' is the angle made by these bones
- The Hock is a joint forming the junction between the adjacent bones, the tibia and fibula and several bones which make up the rear pastern.
- The term 'length of hock' is the distance from the top of the hock joint to the ground. The length of hock encompasses the rear pastern.
The important concepts to understand about forequarter terminology are:
- The withers is the highest point of the shoulder blade and from whence the height of a dog is assessed
- The angle the shoulder blade forms with the humerus is called the 'lay of shoulder' while their junction is a joint called the 'point of shoulder'.
- The shoulder blade and humerus are attached to the dog by muscle only so the shape of the ribcage affects their placement
- The knee sometimes means the joint where the foreleg joins the pastern although technically the knee equates to the stifle joint.
- What is commonly called the pastern is actually the front pastern. This is the dogs' main shock absorber, so its length is important in dogs such as the Borzoi and this Greyhound whose skeleton is illlustrated, whose double suspension gallop requires great flexibility.
The important concepts to understand about body terminology are:
- The height at shoulder is the distance from the withers to the ground
- The coupling is the distance from the last rib to the pelvis. Looking over the dog's back from above, this area is called the loin.
- The croup is that muscular area on the rump of the dog, forward of the set-on of tail. Where there is a sharp decline in angle of the croup, it is can be referred to as droop.
- The prosternum is the most forward projection of the rib cage which forms the front of the forechest.
- The keel, brisket or sternum is the lower curve outline of the chest or ribcage.
- The spring of rib means the degree of curvature of the ribs which form the expandable cage that protects the heart and lungs. The articulation of the ribs with the backbone allows them to expand as the dog breathes.
- Well ribbed back is a separate definition meaning the physical length of the ribcage from prosternum to coupling. Note the last rib is not joined to the sternum and is therefore commonly called a floating rib.
- The back is that portion of the topline from the withers to the set-on of tail.
References and Further Reading:
Harold R Spira 'Canine Terminology' Harper & Row 1982
Re-published by the Irish Wolfhound Association of the West Coast Inc. Newsletter Spring 2014 Pages 13 - 15