Bowed Tendons: Causes & Treatments
By Kimberly A. Rinker

One of the most common cripplers of racehorses is an injury known as a "bowed tendon." In former times it was rare to see a horse with a bowed tendon return to racing, however, in the last few decades progressive surgical techniques have produced full recoveries from such an injury.

In the simplest terms, a bowed tendon is basically the result of tearing of the connecting tissue figures that comprise the superficial flexor tendon. The greatest majority of these tears occur in the middle third of the tendon of the front legs of a horse.

There are many factors, which may contribute to a bowed tendon, and they are as varied as is the degree of damage within the tendon itself. Fatigue resulting in over-flexion of the fetlock (Ankle) is one cause, and if a horse is moved from a relatively hard track to a deeper track, a bow can occur. A change in shoeing angles, lowering the heel, or the introduction of a toe grab are other ways, which could contribute to a bowed tendon. Often, just the wear and tear of racing over the years, combined with a bad misstep can cause a bow.

Occasionally a horse comes out of a training session or race with obvious pain in the leg. This is evident by his gait and obvious heat in the tendon, usually later accompanied by the characteristic "Bowing" of the tendon.

The trainer's first goal in treating a bow is to keep the swelling in check so that the damage to the surrounding tissues does not occur. Usually the horse will be "tubbed" or "iced," that is, he'll be stood in a large tub of ice cold water, or in an ice bucket, a cold whirlpool, or he'll have cold water wraps applied to the affected area.

Recovery depends entirely upon the immediate and follow-up treatment applied to the leg, and of course, the amount of damage done to the tendon fibers. Bows can be repaired sometimes in three months, sometimes in six months, sometimes in a year's time and sometimes never.

To understand the complexities of a bowed tendon, one must first understand the basic makeup of the tendon itself. The connective tissue fibers of the tendon are lined up precisely parallel to the long axis of the tendon. When a tendon is damaged, these fibers are no longer lined up properly.

The repair tissues are made up of disorganized connective tissue fibers. These scar tissues do not form in the lined up manner and when the tendon moves, these scar tissues, which are not lined up properly, will be re-torn. Eventually, however, the tearing of the mis-aligned fibers will stop because most or all of the fibers have realigned.

In recent years, surgical splitting of a bowed tendon has gained a great deal of acceptance and publicity throughout this country. Basically, with this technique, the damaged tendon is cut, and new, fresh tendon fibers grow, mature and form a new tendon. Splitting the tendon also allows for an increased blood supply to the damaged area, and thus, theoretically, for increased healing powers.

Standardbreds prove to be much tougher than their thoroughbred counterparts in regards to recovering from a bowed tendon and nowadays, nearly all are able to make a return to the races after suffering from this mishap. Some do not come back to their former level of performance and trainers don't often ask as much in training after a horse has bowed.