Recurrent laryngeal neuropathy in horses: Understanding diagnosis and treatment

On July 1, 2026, Texas A&M University released an article detailing recurrent laryngeal neuropathy (RLN) in horses, emphasizing the condition's impact during the summer months. Dr. Dustin Major, a clinical assistant professor at Texas A&M's College of Veterinary Medicine, provides insights into how this degenerative nerve condition affects horses' respiratory abilities.

What is recurrent laryngeal neuropathy?

Recurrent laryngeal neuropathy is primarily a degenerative disorder affecting the left recurrent laryngeal nerve, which is crucial for a horse's breathing and vocalization. Dr. Major explains, "The nerve at risk runs from the base of the skull down the neck, wraps around the aorta inside the chest, and then courses back up the neck to support the various muscles that control the larynx." As the nerve deteriorates, the muscle that opens the larynx weakens, reducing the airway's diameter and making breathing increasingly difficult.

One of the first signs of RLN is a characteristic "roaring" sound that occurs when a horse inhales. This sound is produced when the airway pressure causes one of the laryngeal cartilages, known as a "flapper," to collapse, obstructing airflow and creating a high-pitched, vibrating noise. As the condition worsens, horses may exhibit exercise intolerance and decreased performance, particularly in active breeds.

Factors contributing to RLN in horses

While the exact cause of RLN remains unknown, several factors can exacerbate its severity. Dr. Major notes that larger horses, such as racing thoroughbreds and warmbloods, are more susceptible due to the length of their nerves. Additionally, environmental conditions like rising temperatures can increase the risk of developing RLN. "The heat can significantly exacerbate the condition," Major states, "as this results in higher demands on the respiratory system to assist in cooling, particularly when exercising."

Other risk factors include throat trauma and complications from blood vessel injections. As the summer season approaches, veterinarians often see a rise in RLN cases, particularly among horses actively participating in competitions.

Diagnosing and treating RLN

Veterinarians diagnose RLN by reviewing the horse's medical history and conducting a thorough physical examination of the larynx. To confirm suspected abnormalities, they may use an upper airway endoscopy, which involves inserting a small camera to visualize the horse's airway. Dr. Major also recommends dynamic endoscopy, a technique that allows for the assessment of the horse's airway while exercising, helping to identify subtle forms of RLN and other potential airway issues.

Once diagnosed, surgical intervention is often necessary to prevent complete paralysis of the larynx. A common procedure, known as a "tie back," involves retracting the affected cartilage to enhance airflow during exercise. Dr. Major emphasizes, "We will never return the affected horse's airway to its original state. We are just trying to improve airflow to a level that the horse can return to its intended level of performance." Following surgery, a rehabilitation period of six weeks is crucial, during which horses must be monitored closely for recovery.

After surgery, horses typically require ground feeding for a few weeks. If they experience no coughing during this time, they can gradually return to normal feeding practices. Once rehabilitation milestones are reached, horses can enjoy improved respiratory health and performance.

Conclusion

Recurrent laryngeal neuropathy poses significant challenges for horse owners, particularly during warmer months. Understanding the condition, its symptoms, and treatment options can help ensure that horses maintain their health and performance. With proper care and attention, affected horses can return to a happy and healthy life.