A Veterinary Review of
Common Injuries in the Sport Horse

Dr David Platt BVSc., PhD., DEO., FRCVS
Consultant equine orthopaedic surgeon

Many people who keep horses will know the thrills involved in competing with their mounts in endurance or in the show jumping, dressage or eventing arena. Anyone who is involved with competition horses at any level will have at one time or another experienced the frustrations of having their horse suffer from lameness or other debilitating injury. It is particularly pertinent to discuss these issues this month in view of the hard ground at the present time.

Treating sports horse injuries is a specialised area of equine veterinary work since many of the underlying causes of lameness are difficult to accurately locate and treat. Understanding the nature of sports injuries requires the rider to appreciate the forces that can be involved when a fit horse weighing up to 600Kg performs the technical and athletic activities we demand. The power involved in the take-off and the forces of landing during show jumping or the tremendous energy involved in the collected paces of dressage are good examples. The animals conformation and action in addition to the course terrain can all play a part in determining the concussion that has to be absorbed.

Foot Problems
The tremendous impact forces incurred during fast work can result in a variety of injuries. To try to minimise the risks of foot problems it is vital that the horse is well shod and that the shoes are refitted every four to five weeks. The farrier must ensure that the foot is well balanced with a straight foot pastern axis and that the shoe is fitted so that it has no contact with the sole, especially at the seat of corn. This will allow all the concussion to be transferred to the hoof wall and will help to prevent bruising. Bruising on the sole at the junction between the hoof wall at the heel and the bar is termed a corn and is a common cause of foot lameness. Hoof cracks can occur at a number of different locations and can be very frustrating to the owner and rider. Treatment is usually achieved by stabilising the crack using fibreglass adhesive patches applied to the hoof wall in combination to special shoes that have a clip on either side of the crack.

Joint Sprains
Soft tissue injuries to the lining can result in painful tense swellings within equine joints. The most susceptible joints are the coffin and fetlock joints of the front limbs but other joints, such as the large mobile joint of the hock can also be affected. The swelling frequently appears very rapidly following strenuous exercise. Such inflammation in a joint can be secondary to small chip fractures and it is advisable to seek advice from your veterinary surgeon about treatment, which may involve
X-raying the affected area to determine if a fracture is involved. First aid for such injuries involves ice wrapping the affected joint for 30 - 60 minutes before applying a snug well padded stable bandage. There are many proprietary ice bandages available but if you do not have one available a simple solution is to bandage a pack of frozen peas into position around the affected joint. If the sprain is mild, with no bony damage, it may only be necessary to rest the horse for a short period before continuing with light work. If more severe, then a period of enforced rest combined with anti-inflammatory medication followed by controlled handwalking exercise may be required before the lameness resolves. Bony chip fractures inside the joint usually have to be removed using keyhole surgery.

Tendon Injuries
There are four main tendinous structures in the lower limb of the horse that are frequently injured. The superficial digital flexor tendon is the most commonly damaged structure because during normal fast work it is functioning close to its maximum strength. The other structures that can be damaged are the deep digital flexor tendon, the inferior check ligament which is located just below the back of the knee and the suspensory ligament. Tendinous structures are more prone to injury during high speed training but can occur at other times during schooling or competition. When a tendon becomes injured the leg will feel thickened and have an increased surface temperature around the area of damage.

Veterinary attention should be sought immediately if a tendon injury is suspected because it is vital that the inflammatory process within the tendon is suppressed.
Up to 50% of the damage in a strained tendon occurs after the injury and is the result of the inflammation which develops during the first 12 hours in response to the strain. Modern veterinary medicine can help to dramatically reduce this extra damage and therefore minimise the fibre disruption that has to repair. Ultrasound scanning of the tendon structures is the only way to fully assess the extent of the damage and should be done at a very early stage. Modern medications, that can be injected around the tendon or in some cases into the recently damaged tendon, can have dramatic effects on reducing the inflammation. Bandaging which provides counter pressure to reduce tissue swelling is also vital and is combined with strict box rest in the early stages after injury. Recuperation programs involving prolonged controlled exercise instead of unrestricted pasture rest, with ultrasound monitoring, are also revolutionising the quality of tendon repair that can be achieved. Many horses with mild to moderate tendon damage can often be return to their former levels of exercise if the rehabilitation is carefully undertaken.

Fractures
The very nature of the work that we ask horses to perform carries risk of injuries from collision with fences or other obstacles. Fractures are, thankfully, a relatively rare consequence of such injuries but are seen occasionally. The term fracture means any damage to a bone in the skeleton which can range from tiny fragments inside a joint to complete disruption of a major long bone such as the cannon bone. Any severe lameness associated with joint swelling should be investigated by X-ray to determine if a fracture fragment is involved.

Small fragments inside a joint are most easily removed by keyhole surgery (arthroscopy). This technique does very little damage to the joint capsule and the horses are often back in work within 8 - 12 weeks of surgery. Larger fractures involving major long bones are a much greater challenge and require fixation with bone plates to reconstruct the tissues. Not all cases of equine fractures can be repaired but with advances in modern surgical techniques, it is now possible to successfully treat many of the common fractures.

The demands on sports horses is enormous and it remains the responsibility of the veterinary surgeon to help the owner and rider keep their horse in the best possible health so that it may be used to compete. Modern diagnostic equipment can help to localise the site of pain and advances in medication and surgical techniques have made treatment of many injuries far more successful.