Trachea et Bronchi
The trachea is approximately 75-80 cm long and 5-6 cm in diameter, supported by 48-60 C-shaped cartilage rings. It bifurcates into the left and right main bronchi at the tracheal bifurcation (carina). The right lung has 3 lobes and the left has 2 lobes. Horses are obligate nasal breathers and cannot breathe through their mouths. The trachea and bronchi conduct air to and from the lungs and are lined with respiratory epithelium that clears mucus and debris.
Tracheal collapse is uncommon but can occur. Respiratory noise, cough, or exercise intolerance can indicate upper or lower airway disease. Diagnosis uses endoscopy and clinical examination. Relevant in evaluations of respiratory performance and infectious disease.
## Overview Tracheal collapse is weakening of the tracheal cartilage rings that allows the airway to narrow, especially during exercise. It causes respiratory noise, exercise intolerance, and a honki
## Overview Tracheal stricture is narrowing of the tracheal lumen from scarring (after trauma or tracheostomy) or external compression. It causes respiratory noise (stridor) and exercise intolerance.
## Overview Inflammatory airway disease (IAD), now often grouped under mild equine asthma, is chronic lower-airway inflammation without infection as the primary driver. It is common in young performa
## Overview Dorsal displacement of the soft palate (DDSP) occurs when the free border of the soft palate moves above the epiglottis during exercise, obstructing airflow. It produces a characteristic
Persistent cough, nasal discharge, or exercise intolerance should be evaluated. Horses must be able to breathe freely through the nose.
## Overview Tracheal collapse is weakening of the tracheal cartilage rings that allows the airway to narrow, especially during exercise. It causes respiratory noise, exercise intolerance, and a honking cough. It is uncommon in horses compared with small-breed dogs but can occur, particularly in miniature horses or after trauma. ## Causes Cartilage weakness, trauma, or congenital malformation. ## Diagnosis Endoscopy or radiographs showing dynamic or static narrowing. ## Treatment Management of exercise and weight. Surgical stenting or external support in selected cases. Prognosis is guarded for severe collapse. ## Recovery and Prognosis Guarded for athletic use if collapse is significant. ## Prevention None specific. Signs include: respiratory noise during exercise; exercise intolerance; honking cough
## Overview Tracheal stricture is narrowing of the tracheal lumen from scarring (after trauma or tracheostomy) or external compression. It causes respiratory noise (stridor) and exercise intolerance. Endoscopy confirms the narrowing. ## Causes Scarring after injury or surgery, or external mass. ## Diagnosis Endoscopy. ## Treatment Surgical resection and anastomosis for short strictures, or management of the external compression. Prognosis depends on length and location. ## Recovery and Prognosis Fair for short resectable strictures. Poor for long ones. ## Prevention Careful tracheostomy technique and trauma avoidance. Signs include: respiratory stridor; exercise intolerance; diagnosed on endoscopy
## Overview Inflammatory airway disease (IAD), now often grouped under mild equine asthma, is chronic lower-airway inflammation without infection as the primary driver. It is common in young performance horses and causes intermittent cough, excess tracheal mucus, and mildly reduced performance. Horses appear normal at rest. ## Causes Inhaled dust, pollutants, prior viral infection, or airway hyper-responsiveness. ## Diagnosis Endoscopy showing tracheal mucus, bronchoalveolar lavage cytology demonstrating inflammation, and exclusion of more severe equine asthma. ## Treatment Environmental dust reduction, inhaled or systemic corticosteroids, and bronchodilators before exercise. Antibiotics are not routinely effective. ## Recovery and Prognosis Good with management. Many young horses improve as they mature if dust exposure is controlled. ## Prevention Minimize airborne dust and mold in the stable environment. Signs include: intermittent cough; excess tracheal mucus; mildly reduced performance; normal at rest
## Overview Dorsal displacement of the soft palate (DDSP) occurs when the free border of the soft palate moves above the epiglottis during exercise, obstructing airflow. It produces a characteristic gurgling or choking noise and sudden loss of performance. Dysfunction of muscles that position the larynx and hyoid apparatus can contribute. ## Causes Multifactorial: neuromuscular fatigue, inflammation, or anatomic factors affecting palatal stability. ## Diagnosis Exercising endoscopy is required to confirm dynamic displacement. Resting endoscopy is often normal. ## Treatment Options include tack changes, medical management of inflammation, and surgeries such as laryngeal tie-forward or sternothyrohyoid myectomy. Success varies by procedure. ## Recovery and Prognosis Many horses improve with appropriate treatment. Recurrence is possible. ## Prevention Management of airway inflammation and appropriate conditioning. Signs include: gurgling or choking noise at speed; sudden slowing; resolves when the horse swallows; exercise intolerance
Tracheal collapse is uncommon but can occur. Respiratory noise, cough, or exercise intolerance can indicate upper or lower airway disease. Diagnosis uses endoscopy and clinical examination. Relevant in evaluations of respiratory performance and infectious disease.
Persistent cough, nasal discharge, or exercise intolerance should be evaluated. Horses must be able to breathe freely through the nose.
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