Description

Bone spavin is a syndrome more than a disease because of the numerous causes and treatments. The hock has four joints. The lower three hock joints do not have much motion and act as shock absorbers when the horse is running or working.

Bone spavin is seen in mature horses that are ridden hard, used for running, pulling, jumping, roping, reining, cutting, and other show events that require a horse to work off the hind limbs.

With the repeated compressions and rotation of the hock joints and surrounding structures, the area becomes sore and inflammation develops which can lead to cartilage degeneration and bony proliferation. Bone spavin is much like arthritis in people. The remodeling and later fusing of the joint is the body's way of getting rid of the problem.

Symptoms

• Soreness in the hock area
• Decrease in performance
• Lameness
• Changes in stride and dragging of hind limbs

Causes

Bone spavin is caused by hard riding that places unnatural demands on the horse's limbs with repeated compression and rotation of the distal hock joints and repeated ligament tension on the front inside part of the joints, causing trauma and inflammation of the joints and surrounding tissues and structures.

Bone spavin is also associated with horses that have had infections of the hock joints, metabolic bone disease, fracture or developmental problems. Unfavorable conformation such as sickle or cow hocks create increased stress on the inside part of the distal hock joints and can result in bone spavin.

Prevention

If bone spavin is the result of conformation, little can be done to prevent it. The best prevention, in the case of working horses, whether they are show horses or working horses on a ranch, is to make sure that they have "down time" between hard riding events to allow the joints and tissues to mend or heal.

Some bone spavin can be prevented by immediate attention to inflammation in the horse's  joints whenever it occurs. Prompt treatment of injuries or conditions that result in joint inflammation is important in preventing future cases of bone spavin.

Treatment

Treatment of bone spavin can be divided into two types: reduction of inflammation and joint fusing. In both cases, the goal is to make the horse pain free. In cases of long-term bone spavin, the affected joints need to fuse together to decrease movement and help keep the horse sound. These fusion procedures, known as arthrodesis, can consist of laser arthrodesis, plating, hock drilling or chemical arthrodesis.

Non steroidal anti-inflammatory drugs are used to reduce pain and inflammation in the affected joints. Combined with rest, followed by a light work schedule, these treatments will keep some horses sound or at least sound enough to ride.

Oral supplements such as chrondroitin sulfates and glycosaminoglycans can aid greatly in maintaining horses with degenerative joint disease of the hocks by protecting and improving the health of the cartilage in the joint.

In some cases injections of corticosteroids, hyaluronic acid, polysuphated glycosaminoglycans or a combination of treatments may be necessary to reduce pain and inflammation. Substances that reduce bony friction, lubricate the joint, and reduce the pain have also been tried including high grade silicon, snake venom, and other concoctions. These should be given only by a knowledgeable veterinarian who has had previous experience with such remedies.

Recently, high energy shock waves have been applied to the joint area and surrounding structures in a few horses. It is thought that the shock wave energy may stimulate cell division increasing the number of bone-making cells, improving circulation and relieving pain. Long term effects are not fully known.

In any case of severe bone spavin, a reliable veterinarian with experience and knowledge of the various ways bone spavin may be treated should be engaged to determine what works best for a particular horse. The end goal is to relieve pain, prevent further injury, and bring the horse back to the level of activity that keeps both the horse and the handler comfortable and satisfied with the activities at hand.