The Causes and Cures of Splints

Equine Splints are unsightly and can cause long term issues to your horses soundness.  To manage them well, it is important to learn how to keep splints from becoming permanent blemishes or problems that interfere with your horse's athletic career.

So What are Splints?

Splints are an inflammatory condition of the splint bones. They occur primarily in growing horses involved in heavy training. The Splint bones are located on each side of the cannon bone. Between the splint bones and the cannon bone is the interosseous ligament, which is made of a dense connective tissue that turns into bone as the horse grows into an adult. This ligament fuses with the cannon bone and splint bones.  The bony fusion is usually complete in most horses by 3-4 years of age.

Splints happen due to:

1.      Tearing of the interosseous ligament

2.      External trauma to the bone

3.      Secondary to healing of a fracture.

Splints commonly occur in 2- to 3-year-old horses, occasionally in horses 4 years of age and older, and are usually associated with training and subsequent injury. Splints usually occur on the inside of the front leg, about 3 inches below the knee, although they can occur on the outside splint of the front or rear legs.

There are four types of splints:

1. True splint This is a fibrous and bony enlargement on the splint bone which began as swelling because the interosseous ligament suffered a tear or other damage.  The inflammation can e easily seen.
2. Blind splint The inflammation caused by an injury to the interosseous ligament causes a fibrous and bony enlargement between the splint bones and the suspensory ligament (i.e., little to no external swelling).  Depending on the severity, this could have a profound long term affect on soundness due to the interference it causes to the suspensory ligament.
3. Periostitis This inflammation and bony reaction is secondary to trauma to the periosteum which is the soft tissue covering bone.
4. Knee splint This type of splint involves swelling located at the top part of the splint bone right near the knee. It involves the lower joint in the knee, resulting in osteoarthritis.  If your horse has this then it is likely that it will be unsound for life.

Risk Factors

Ø  Young horses in heavy training.

Ø  Working/keeping your horse on hard surfaces

Ø  Conformational abnormalities such as an offset knee, base narrow, toe-out conformation

Ø  Improper hoof balance

Ø  Mineral imbalances

Ø  Over-feeding

Ø  Brushing of your horses front legs against one another

Signs your Horse is Developing Splints

Heat, pain, and swelling along a splint bone in a 2- to 4-year old horse suggests a splint. The swelling may be painful to palpation initially, but as the inflammation subsides, the swelling becomes firm and no longer painful.  If your horse has lameness it is usually mild and most evident at the trot. Exercise on hard ground will make the lameness worse. When a mild case occurs, no lameness may be evident at the walk.  Lameness might come and go or be continuous.

Swelling that is painful to touch is usually sufficient enough evidence for indicating splints.  However to gain an firm diagnosis an xray is needed to rule out a splint bone fracture, and to record size of bone grow in relation to simply swelling of the area.  This establishes a baseline for monitoring and predicts the degree of permanent cosmetic bony swelling.  It also helps determine the potential for the bone growth to interfere with the suspensory ligament, which could cause ongoing lameness.

Ultrasound may also be useful to determine if the splint is actually causing damage to the suspensory ligament. In some cases bone scans and other investigations may be needed to evaluate splints that are located between the splint bone and the suspensory ligament.

Treating Splints

There are various means of treating splints. Rest until the area is no longer painful  is mandatory. This usually means 6 weeks however it could extend out to two to three months.

Other things you can try:

Ø  Cold therapy with icing cold hosing, to decrease the swelling and inflammation

Ø  Pressure bandaging to reduce swelling

Ø  Oral non-steroidal anti-inflammatory drugs to reduce inflammation

Ø  Topical anti-inflammatory drugs

Ø  Injections of corticosteroids around the splint may decrease inflammation and reduce the size of the splint.

Ø  For cases caused by  interference due to  improper trimming or shoeing, have the horse shod and trimmed to prevent further interference or stress on the area (by a better farrier!)

Ø  Some chronic or severe cases might require surgery to remove the bony swelling or to remove a portion of the splint bone. Surgical treatment may be considered later once the inflammation and bone formation has stopped). The disadvantages of surgery are the risks and expense of performing surgery and that a bony reaction might recur after surgery.

Ø  Lasers, ultrasound, and pulsed electromagnetic therapy may reduce inflammation and also speed healing.

Prognosis

After all inflammation has subsided, the horse can gradually return to work.

The prognosis is good to excellent except for those cases in which the bony growth is large and interferes with the knee joint or the suspensory ligament.  In most cased your horse's soundness will not be affected, although most horses will have a bony lump remaining once the inflammatory response has resolved. While it may not be visible in all cases, you will be able to feel it. Most high level performance horses have visible knots on the inside splint bone.

Prevention

Ways to prevent splints are:

 Slowing down the intensity and frequency of your young horse's work

Provide proper nutrition, and avoid obesity

 Maintain proper foot care

Prevent limb interference by using protective splint boots during training

When choosing protective splint boots, look for a padded boot that provides more reinforced or rigid protection, especially along the inside length of the cannon bone. Boots can be synthetic or leather, but should have extra padding and material to absorb or dissipate the impact of hoof interference. Simple unreinforced neoprene leg wraps, Vetrap, or cloth stable bandages don't provide sufficient protection against splints.

Remember

Don't assume that a 'splint' is a simple problem. Act quickly and treat aggressively by reducing the inflammation and the resulting bony reaction, you can minimize the risk on your horse developing a long-term problem which could impact on his soundness and beauty.

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