The healthy equine joint

In order to understand arthritis, it is useful to understand the structure of a healthy joint. Joints are made up of several important structures that work together to provide stability and shock absorption.

Cartilage: The ends of the bones are covered by a smooth layer called cartilage which provides a protective surface and enables frictionless motion within the joint.

Joint capsule: This is the tough outer layer of the joint that works together with the joint ligaments to provide support.

Synovial (joint) fluid: This is a thick f luid that fills the joint. It has two functions: lubrication of the joint and provision of the main source of nutrients to the cartilage.

In a horse with arthritis these structures don’t perform their functions as well as they should, and this results in a reduced range of movement and pain in the joint.