What Is Upper Airway Endoscopy?
Upper airway endoscopy is a really useful tool to allow us to investigate and diagnose a wide range of upper airway diseases and conditions.
It is minimally invasive and tolerated very well by the patient with just light sedation.
Why Would My Horse Need Endoscopy?
Endoscopy allows us to make a definitive diagnosis and therefore formulate a safe and appropriate treatment plan not only to achieve a more effective treatment result but also to reduce the potentially dangerous side effects of treating these respiratory conditions blind.
What Does Upper Airway Endoscopy Involve?
First we listen to the horse’s chest at rest. This is to detect any abnormalities before any exercise is performed and allow us to obtain a resting respiratory rate.
Next the horse is placed on to the lunge. This is to allow us to identify any abnormal breathing sounds any coughing and also to mobilise any secretions or discharges within the respiratory tract, which would allow sampling of them to become easier.
The horse is slowly walked in to the stocks, to allow for easy comfortable restraint and allow a lower dose of sedation to be used.
The horse then has his chest and heart listened to again. This is to detect any changes pre and post lunging and also to make sure we are ok to give intravenous sedation prior to the procedure.
Once the horse is adequately sedated the endoscope is lubricated and passed slowly and gently up one of the nostrils until it reaches the level of the larynx, which is at the back of the throat. As you can see they tolerate this very well.
The aim of the first part of the examination is to visualise the larynx, which marks the entrance to the upper respiratory tract, the trachea or the windpipe. Here we look for the presence of any swellings, or masses or growths, that both sides of the larynx are symmetrical, there is no inflammation or reddening – basically that everything looks to be working as it should.
Once we are happy we then advance to the next stage.
The endoscope is advanced through the larynx, and into the top part of the trachea. Here we are checking if the trachea is a normal size and shape and also examine the trachea for the presence of any abnormal mucous or secretions.
The endoscope is then advanced all the way down the trachea til reach the carina, which is the level at which the trachea splits to form the left and right lung lobes. Once we are happy that a thorough examination of the entire trachea has been performed, a sample of the mucous is taken (a tracheal wash). A sterile catheter is advanced down through the endoscope and a set volume of sterile saline is administered. The saline is then retrieved back through the catheter, bringing with it a sample of the mucous and cells that are present within the trachea. The catheter is then pulled back inside the endoscope before removal, so not to damage the lining of the trachea.
The endoscope is then slowly and gently removed from the horse’s respiratory tract and nose.
The samples are then decanted in to mediums to allow for cell preservation and transportation to a laboratory for testing.
The patient is then allowed to come around from sedation in how own time, but as you can see is none the wiser from the procedure that he has just undertaken.