Diagnosis of upper respiratory tract disorders in horses using a cheap, smartphone‐connected, flexible and steerable borescope

Abstract

SummaryBackgroundEndoscopy is essential for the diagnosis of upper respiratory tract (URT) disorders in horses but equipment is expensive. An industrial borescope might be used to visualise the URT when an endoscope is not available.ObjectivesTo investigate the applicability of a cheap, smartphone‐connected, flexible and steerable borescope to perform URT endoscopy in horses.Study designProspective descriptive study.MethodsIn horses with a clinical indication, endoscopy was first performed with a borescope and subsequently with a veterinary endoscope, which was used as gold standard. Typical URT structures of interest (depending on clinical signs) were digitally recorded. Recordings of both examinations were reviewed by a blinded observer.ResultsOne hundred horses underwent both endoscopic examinations via the right (n = 100) and left (n = 24) nasal passage. In 81/83 attempts, the ethmoidal labyrinth and sinus ostia were visualised on the right side and in 22/24 attempts on the left side. Pharyngeal and laryngeal structures could always be visualised except in 6 horses where the tip of the epiglottis could not be seen due to technical failure of the steering mechanism. In 66/72 attempts, the trachea could be visualised proximally, of which the carina was visualised in 59. Borescope and endoscope grading scores for pharyngeal lymphoid hyperplasia, recurrent laryngeal neuropathy and tracheal mucus were identical in 88/100, 93/100 and 48/59 horses, respectively. The remainder differed only one or two subgrades. The borescope was replaced halfway through the study as the steering mechanism started to fail after 45 to 50 examinations.Main limitationsLack of reliability and the absence of a working channel of this particular borescope model.ConclusionsA flexible, steerable borescope, connected to a smartphone, allows visualising specific parts of the URT in horses.