Helping Roarers Breathe Easy

Horsemen can get caught up in the specifics of their disciplines, but the basic needs of sport horses, like all athletes, are simple: water, food and air.

The act of breathing, so commonplace that it’s often taken for granted, is of such importance in equine athletes that race horses with one tiny misalignment in the upper airway can immediately be destined for a different career.

“Roaring,” formally known as left laryngeal hemiplegia, is an upper airway obstruction that occurs when a horse suffers from paralysis or weakening of one of the crucial structures in his throat.

As the name indicates, horses with a roar often exhibit raspy or wheezy breath during strenuous exercise. Although the disease can be traced back to a nerve issue, the noise is essentially caused by a piece of cartilage flapping in the horse’s airway instead of pulling back properly to allow for the maximum flow of oxygen during exercise.

The disease is considered idiopathic, meaning vets aren’t usually sure why some young horses, especially Thoroughbreds and draft horses, are stricken with it.

For years, the only fix has been a surgical procedure, formally known as laryngoplasty but commonly called tie-back surgery, to literally “tie back” the offending cartilage. The goal: eliminate the noise and make sure horses can get a normal amount of air during periods of intense exercise.

These days, advances in medicine are opening the door for better surgical procedures to treat roaring. A few years ago, Eric Parente, an associate professor of surgery at the University of Pennsylvania’s New Bolton Center, pioneered a process of fusing a joint in the throat to increase the success rate of keeping the airway open.

“One goal we have is to better understand the cause of the disease and the biomechanics of the disease so we can figure out the best way to correct it,” said Parente. “It’s like, before you build a better mousetrap, you have to know how big the mouse is.”

Parente is working on an even better procedure to treat roaring, but that procedure is too new to discuss yet. Meanwhile, other researchers and surgeons are experimenting with laser surgery to zap off the other, smaller pieces of tissue that cause only the noise in a horse’s throat. Tie-back surgery, which requires full anesthesia, aims to eliminate the noise and the entire airway obstruction.

Another procedure involving nerve grafts is also getting some attention, but the success rate of that technique is not as high as some of the other more traditional procedures, Parente said.

The Cause Of The Noise

Although roaring is most often seen in Thoroughbreds and draft horses, it’s now being diagnosed in more warmbloods, said surgeon Courtney Bollam at the Wisconsin Equine Center Clinic in Oconomowoc.

According to the New Bolton Center, non-race horses make up about 15 to 20 percent of the horses afflicted with the disease. The disease is usually noticed in horses when they are 2 or 3. Occasionally, trauma to the neck such as a sharp kick or a misplaced intravenous injection can cause the condition. An endoscope is used to diagnose a roarer, and horses are rated on a scale to rank their severity.

Internally, the problem is a paralysis of one of two arytenoid cartilages in the throat. Almost always, the left cartilage is the one that fails to work properly.