Navicular Syndrome

Navicular Syndrome is a term used to describe pain in the region of the distal sesamoid bone.

Introduction

Navicular syndrome is not a disease; it is a terminology used to describe pain in the region of the distal sesamoid bone (x-rays are taken to rule out bone disease or bony changes that could be the underlying problem). Navicular Syndrome has been a problem in equines for many years; however it tends to primarily show up in the equine athletes in their prime of life. It is something that can cause pain and in some cases it will cause the end of the animal's working life. This is due to the degenerative effect it has on the soft tissue and Navicular Bone over time (and this can be a short or long time frame). Veterinarians and clinical researchers along with farriers have been trying to unravel the causes for centuries, and still have no real prescription as to what causes this syndrome.

Overview

The navicular bone sits in the back section of the foot in-between the wings of the pedal bone, its function is to act as a fulcrum for the deep digital flexor tendon and maintain tension and the location of this tendon. It is held in place by the impar ligament attaching it to pedal bone and on the sides by the collateral sesamoidean ligaments attaching it to the middle pastern bone. With the physical forces impacting upon the foot, in particular the intersection of the pedal bone and navicular bone you can see that excessive forces could cause sufficient trauma to the soft tissue of this region.

This ongoing trauma will have an inflammatory process on the soft tissue and this will modify the functioning of the foot during the horse moving or just standing. This inflammatory process places extreme pressure on the foot during movement and the navicular bone and deep flexor tendon become extremely sore and the horse changes it weight on the limb involved. This is usually due to bruising in this area internally and x-rays do not tend to show these signs, therefore it is hard to diagnose, and is given the term Navicular Syndrome.

However if not treated correctly and early, it could develop into Navicular Disease where the wearing surface of the navicular bone shows signs of the disease.

Animal's Response

In the beginning the animal will start to show signs of behavioural changes and of not coping with the work load and you could notice things like: them not moving freely – reluctance to take weight on the involved limb – holding the involved limb or foot off the ground – having good days and other days when they cannot cope – swelling in the lower limb or signs that could be mistaken for an abscess.

What Can You Do?

View this syndrome as an early warning sign of imbalance in the equine and if not addressed correctly then long term problems will manifest throughout the horse's body. Have the foot x-rayed to rule out bone issues and have a competent consultant check the orthopaedic balance of the animal.

Please contact your consultant if you have any additional questions. Download Factsheet