Dynamic endoscopy, also known as stress endoscopy or overground endoscopy, is an examination procedure that enables visualisation of the upper respiratory tract, especially the larynx and pharynx, during movement on the lunge or under the rider.

Frequent indications for which this examination procedure is used at the Bargeteheide Equine Clinic are respiratory noises or poor performance. A stress endoscopic examination can be particularly useful if no findings that could lead to a breath sound were found in the resting endoscopy or if the degree of the findings does not correlate with the volume of the breath sound.

Dynamic diseases of the upper airways that cannot be diagnosed at rest or can only be diagnosed to a limited extent, such as dorsal displacement of the soft palate, dynamic pharyngeal collapse or deviation of the aryepiglottic plica, can be diagnosed much more reliably using dynamic endoscopy. Dynamic endoscopy can also be useful for assessing the severity of laryngeal whistling, especially when deciding whether a horse needs to undergo laryngeal surgery (see upper airway surgery).

To perform the examination, the horse can be lightly sedated and the nostril through which the endoscope is inserted can be anaesthetised using a local anaesthetic. The endoscope is then inserted through the nostrils and adjusted to the desired position in front of the larynx or in the pharynx. A special head piece allows the endoscope to be fixed to the horse's head. The images are transmitted to a connected mobile phone, which is also attached to the headpiece.

Once the endoscope has been attached, the horse can be moved freely on the lunge or under the rider, and most horses tolerate the endoscope without any problems after a period of familiarisation.

It makes sense to recreate the situations in which the rider initially observed the breathing noise or the drop in performance.