Respiratory Noises in Exercising Horses

Here's how to investigate the strange noises your horse may be making as he works.

Respiratory noises are most commonly heard at faster gaits, such as the canter or gallop.

Janne Matzner

Janne Matzner

A horse who emits rasping, whistling or other respiratory noises when he gallops may have a condition called roaring, technically known as laryngeal hemiplegia.

Roaring occurs when the muscles on one or both sides of the larynx are weak or paralyzed. As a result, the cartilages in the larynx (arytenoids) and the vocal cords sag into or even block the airway (trachea), restricting breathing and producing a roaring sound. Trauma, neurological damage or infection can precipitate roaring, but most cases have no known cause.

If you suspect your horse is a roarer, call your veterinarian, who will use an endoscope to make a diagnosis. In addition, be prepared to answer some questions that can help the investigation.

? What do you hear? Laryngeal hemiplegia produces noises that range from a loud rasping and whistling to a soft purring or snoring sound. The greater the airway blockage the more high-pitched and loud the noise becomes. Some roarers also cough during exertion.

? When does the sound occur? Roaring usually happens as the horse inhales when galloping because damaged arytenoids cannot open wide enough to draw in the air needed for exertion. A headset that results in extreme flexion at the poll can also trigger the noise.

? Is your horse's performance affected? A roaring horse may tire easily and take longer than expected to catch his breath after a gallop. If the larynx is completely blocked, he might seem to panic, ?shutting down? and pulling himself up.