An endoscope is a device that consists of a long thin hose coated with fiber optic cables on the inside: via these cables a video image can be made and shown on a monitor.

Endoscopy is a minimally invasive medical procedure and is often used to examine a part of the body to confirm a diagnosis when other devices, such as an MRI, X-ray, or CT scan are considered inappropriate. Furthermore, via an endoscopy samples of tissues (such as the lungs and intestines) can be taken without the need for major surgery. Some surgical procedures can be carried out with a modified endoscope, such as the removal of small superficial tumours. Flexible endoscopes are needed to thoroughly examine the depths of tubular structures that turn corners (e.g. stomach, intestine, bronchial tree, and male canine urethra), but rigid endoscopes are more convenient for examining nontubular structures, such as the abdominal cavity, thoracic cavity, or joint spaces.

This examination is used to take a peek inside the body via body orifices and possibly take biopsies during the process. The patient is completely sedated during this procedure.