Overview
A quadrupedal body plan
The dog’s trunk is suspended between four limbs while the vertebral column runs horizontally from skull to tail. This orientation changes how anatomical directions are described and how forces travel through the skeleton during movement.
The thoracic limbs attach to the trunk primarily through muscles rather than a bony joint. The pelvic limbs connect through the sacroiliac joints and provide much of the propulsive force in running and jumping.
Body regions
Head and neck
The skull protects the brain and supports specialized organs for smell, hearing, vision, and feeding. The mobile neck positions the head while transmitting nerves, vessels, air, and food.
Thorax and abdomen
The thorax contains the heart and lungs within the rib cage. Caudal to the diaphragm, the abdomen houses most digestive organs as well as the kidneys and other structures.
Thoracic and pelvic limbs
The forelimbs absorb impact and assist braking and steering. The hindlimbs contain larger muscle groups that extend the hip, stifle, and hock to drive the body forward.
Movement
Walking, trotting, and galloping require precisely timed limb cycles and coordinated spinal motion. Muscle groups alternate between propulsion, stabilization, and controlled deceleration.