Respiratory Endosocopy
An endoscope is a narrow, flexible, fibreoptic camera that can be passed into the body to view internal parts. Respiratory endoscopy is the most widely performed endoscopic procedure in the horse, although gastroscopy (to view the inside of the stomach) is becoming more common nowadays. Respiratory endoscopy allows visualisation of a large portion of the upper airway of the horse from the inside of the nostrils right down to the bronchial bifurcation, where the bronchi split to travel to the left and right lungs.
Visual examination of the inside of the guttural pouches can also be facilitated by guiding the endoscope into the guttural pouches (large air-filled cavities either side of the throat which house some important blood vessels and nerves). As such there are a wide range of situations where respiratory endoscopy can provide really useful information:
Nasal discharge or haemorrhage (nosebleeds) – to identify the source which could be sinuses, guttural pouches, lungs, or ethmoid turbinates
Noisy breathing, heard at rest or during exercise – to identify structural abnormalities within the airway such as laryngeal hemiplegia (also known as roarer syndrome), nasal tumours, epiglottic cysts or entrapment
Coughing and respiratory infections – to assess airway inflammation, look for mucopus in the airway and in some cases obtain samples, for example tracheal mucus for bacterial culture
Poor performance – to identify structural abnormalities or inflammatory airway disease
A wide range of conditions can be definitively diagnosed using endoscopy making it an extremely useful tool in the work-up of respiratory problems. It is inexpensive, quick and easy to perform out in the field. In some cases other diagnostic techniques, such as blood tests, ultrasound or x-rays may be needed in conjunction with endoscopy in order to reach a diagnosis. Dynamic respiratory endoscopy (right) which provides a video of the throat during exercise, is also a very useful tool for poor performance cases or horses making noise during exercise, where resting endoscopy doesn’t identify any abnormalities.
