Recurrent laryngeal neuropathy (RLN) research: where are we and to where are we heading?

The research article discusses the current understanding of Recurrent Laryngeal Neuropathy (RLN) in horses, explores its impact on equine health, and assesses the different aspects of the disease such as its etiology, pathogenesis, possible genetic links, and treatment options.

Understanding Recurrent Laryngeal Neuropathy

• Recurrent Laryngeal Neuropathy (RLN), also known by various synonyms like idiopathic laryngeal paralysis, roaring, whistling, or laryngeal hemiplegia, is a major airway disorder prevalent in horses. It has been the object of many studies and is extensively documented in various textbooks.
• This disease primarily affects one side of the larynx, often the left side and is more common in taller horses. It obstructs the airway leading to reduced exercise performance especially in horses that exert heavy physical efforts.
• In its severe form, named hemiplegia, RLN can even impact the working of horses at slower speeds, such as draught horses.
• Although the clinical expression of RLN is still high, estimated between 2.6–8.3%, most research and veterinary response to this disorder have focused on surgical treatments and dealing with its ensuing consequences.

Need for Comprehensive Research

• The research acknowledges that there has been minimal investigation concerning the aetiology, pathogenesis or any potential hereditary nature of RLN. The prevailing focus tends to hover around its diagnosis and surgical treatment.
• The Havemeyer workshop on RLN in 2003 brought about a resurgent interest in studying this disorder more comprehensively. The gathering of specialists from different fields like neurologists, surgeons, geneticists and equine practitioners spurred more inquiries into the disease.
• This renewed interest is evident as the last year has seen multiple papers on equine laryngeal studies being submitted for review to the Equine Veterinary Journal.

Areas of Focus

• This research paper sums up the ongoing studies concerning different aspects of RLN such as its aetiology, pathology, genomics, diagnostic evaluation, surgical therapies, and the outcome of these treatments. The goal is to develop a more holistic understanding of the disease, moving beyond just diagnosing and treating it surgically.