Vocal cord displacement – how dangerous is it?

The soft palate is a muscle extension approximately 10 cm long that separates the nasal cavity from the throat. As the name suggests, dorsal displacement of the soft palate (DDSP) describes a change in position in which the soft palate temporarily or permanently covers the epiglottis, leading to coughing, difficulty swallowing, and breathing problems.

INHALT
Causes Symptoms Diagnosis Treatment Forecast
Causes

Temporary displacement can occur in racehorses or sport horses due to strenuous exertion in the form of "choking up." However, muscle paralysis following respiratory diseases (such as strangles) or general pain can also trigger palatal displacement. Occasionally, palatal displacement is associated with unilateral laryngeal paralysis.

Diagram of the larynx in horses
1 Arytenoid cartilage | 2 Trachea | 3 Epiglottis | 4 Vocal cords | 5 Vocal folds | 6 Uvula (located on the epiglottis)
Schematic diagram of a horse's head in sagittal section
Longitudinal section: 1 soft palate (moved to the epiglottis) | 2 epiglottis | 3 trachea
Symptoms

The first symptoms are usually only noticeable under stress. In racehorses in particular, a displacement of the soft palate during faster gaits can lead to acute respiratory distress. During exhalation, rattling, snoring, or vibrating breathing sounds can be heard. Prolonged coughing fits and mouth breathing may also be observed occasionally.

Diagnosis

The veterinarian can obtain clear indications of a soft palate displacement through a general clinical examination and auscultation (listening with a stethoscope) before, during, and after exercise. With the help of a further endoscopic examination of the upper respiratory tract, the exact position of the soft palate can be determined and the diagnosis confirmed.

Treatment

In cases of temporary palatal displacement, loosening the teeth and pulling out the tongue is usually sufficient. If there is an underlying condition, treating this is usually enough to make the symptoms disappear.

If there is a permanent or recurring displacement, surgery is recommended. Various surgical methods have been developed over time. These involve either shortening the soft palate itself or certain muscles that pull back the larynx. This can be done using conservative surgery, electrosurgery, or laser surgery. Your veterinarian will discuss the most appropriate method for your pet's individual case with you.

Forecast

The prognosis for recovery after palate surgery is considered favorable. The success rate for horses treated with electro- or laser surgery is between 60 and 70%.