Whistling & Roaring

Horses that produce an abnormal inspiratory noise during exercise are commonly referred to as “whistlers” or “roarers.” This whistling & roaring noise is heard exclusively during the inspiratory phase, varying in sound from a high-pitched whistle to a loud, roaring noise. The intensity and character of the sound can differ significantly depending on the underlying cause.

What Causes Whistling & Roaring?

Any factor that disrupts the normal flow of air from the nostrils to the lungs can result in an audible noise during breathing. The most prevalent cause of these respiratory noises in horses is a condition known as laryngeal hemiplegia. This condition arises when one of the two vocal cords within the larynx (commonly referred to as the voice box or Adam’s apple) becomes paralysed. The paralysis is typically attributed to damage or injury to the recurrent laryngeal nerve, which runs along the neck of the horse. When this nerve is compromised, the affected vocal cord fails to open properly during inspiration, leading to the characteristic noise.

Another condition, known as epiglottic entrapment, can also result in whistling and roaring. This occurs when the epiglottis, a flap of tissue located in the throat, becomes trapped and cannot move freely. This entrapment disrupts the normal airflow, creating an abnormal sound during breathing. Additional causes of whistling and roaring include tumours, cysts within the larynx, infections, and congenital abnormalities (birth defects) affecting the structure of the larynx.

What Are the Signs of Whistling & Roaring?

The primary sign of these conditions is the presence of an abnormal noise during inspiration. In mild cases, this noise might only be noticeable when the horse is engaging in strenuous exercise. However, as the condition progresses, the noise may become evident even at a trot, potentially affecting the horse’s performance and comfort.

What Can Be Done to Prevent Whistling and Roaring?

Unfortunately, there is no definitive way to prevent these conditions from occurring. However, early diagnosis and treatment are crucial in preventing further complications and ensuring the horse’s wellbeing. Surgical intervention, commonly known as a “tie-back” surgery, is often successful in resolving the issue. This procedure involves placing sutures in the larynx to hold the paralysed vocal cord out of the airway, thereby reducing or eliminating the noise.

It is also important to note that laryngeal hemiplegia is believed to have a hereditary component. Therefore, if you suspect your horse is suffering from this condition, it is advisable to seek further advice from your veterinary surgeon. Early consultation and intervention can make a significant difference in managing the condition and improving your horse’s quality of life.