Laryngeal whistling
The larynx pipes ( lat. Laryngeal hemiplegia , also Pfeifer steam , Hartschnaufigkeit , Roaren ), commonly referred to as "tones" is one in horses occurring chronic respiratory failure due to a unilateral laryngeal paralysis of the sick animal. The larynx whistling was a so-called warranty defect until January 1, 2002 . It corresponds to the carcass position in human medicine .
root cause
The cause of the larynx whistling is damage to the left recurrent laryngeal nerve . This nerve supplies all muscles of the larynx with the exception of the cricothyroid muscle . Due to the wrapping around the aorta, it is exposed to particular stresses due to tension and pressure. Nerve damage leads to left-sided paralysis of the vocal fold . This flutters in the air flow, which creates the characteristic noise and leads to a disturbance when breathing in ( inspiratory dyspnea ) under stress.
Symptoms
When you breathe in, you can hear a hard, roaring, pitch-like sound ( roaring ). This is usually caused by unilateral, mostly left-sided vocal cord paralysis.
The horse may not be able to exert greater or prolonged exertion, as the obstruction of inhalation under exertion leads to shortness of breath . The horses can react to the shortness of breath by refusing to exert themselves or with panic and go through with it . However, this is not always the case, some horses can be ridden without problems despite the larynx whistling and can withstand any kind of exertion. However, these animals should be examined regularly by the vet to prevent damage to the lungs.
therapy
The restoration of nerve function is not possible. There are various surgical techniques that cause a passive tightening of the left vocal cord and thus eliminate the symptoms or reduce the air resistance with an implant and increase the air flow.
