Equine: Endoscopy

When a person or animal is unwell, external symptoms and blood test results may only tell part of the story. Advances in medical technology mean that it is now possible to see what is actually happening inside the body. One of the procedures that is being used in humans as well as animals, including horses, is called an endoscopy.

An endoscopy can be used to view and analyze many parts of a horse including the upper respiratory tract as well as parts of the gastrointestinal, reproductive and urinary tracts in order to help veterinarians make accurate diagnoses and recommendations for treatment on a wide range of health problems.
 

Types of Endoscopy

There are two main types of endoscopies available in the equine veterinary field. They are:
 

Fiberoptic Endoscope

This is the most common type of endoscope used for investigative surgery in horses. The endoscope is made up of a bunch of optical fibers that are enclosed within a waterproof rubber tube. The tube is passed into the horse’s body either through a natural body cavity or through a surgical incision. The area is illuminated by a light source that passes through the fiber optics and then examined using an eyepiece that is attached to the external end of the fiber-optic cable.
 

Video Endoscope

This more advanced version of the endoscope has a tiny microchip video camera on the end of the scope which relays live feedback to a television screen in the room. This means that multiple people can view the feed, and it can be recorded and played back at a later time.

Why might equines require an endoscopy?

Health problems are a concern for any responsible animal owner and an endoscopy may be recommended to help with diagnosing any number of conditions. However, endoscopies are routinely used in the sale/purchase of racehorses. This is because they can accurately identify the presence of a laryngeal condition that can affect the ability of a racehorse to successfully perform.
 

Equine endoscopies and laryngeal hemiplegia

Laryngeal hemiplegia (also referred to as recurrent laryngeal neuropathy or laryngeal paralysis) is an important and not uncommon condition amongst racehorses where the nerves that supply the muscles of the larynx become diseased, impeding their ability to function correctly. This prevents the larynx from opening completely, preventing the animal from taking adequate breaths and consequently reducing its’ ability to perform at full capacity.

Racehorses with laryngeal hemiplegia make an unusual ‘whistling’ noise when they breathe, caused by the narrower airway. An endoscope inserted into the upper respiratory tract will be able to identify the condition and this examination is commonly known as ‘the wind test’. Portable endoscopes are often used at horse sales/purchases for this reason so that the buyer can be sure that their horse is in good health and will be a sound investment. Trying to race a horse that suffers from laryngeal hemiplegia would be irresponsible as it could prove to be extremely dangerous to their health as they struggle for adequate breath.