Endoscopy and Colonoscopy
An endoscope is a flexible tube with a viewing port and/or a video camera attachment that is inserted either into the stomach through the mouth or the colon via the rectum. The endoscope permits inspection of the inside of these hollow organs. If the stomach is being examined, the esophagus can be inspected as the endoscope is being passed into the stomach.
In many cases your veterinarian can diagnose cancer of the gastrointestinal tract using the endoscope. However, some tumors do not affect the mucosa or inner lining of the stomach or colon. Since the biopsy procedure only samples the mucosa it is possible to miss detecting a tumor that involves only the deeper layers of the intestinal tract. In these unusual cases, the biopsy results are normal yet the dog continues to experience clinical signs. In order to reach a diagnosis in these cases, full-thickness biopsies obtained through an exploratory surgery, (exploratory laparotomy) or non-invasive tests such as an MRI (Magnetic Resonance Imaging) may be required.
In many cases your veterinarian can diagnose cancer of the gastrointestinal tract using the endoscope. However, some tumors do not affect the mucosa or inner lining of the stomach or colon. Since the biopsy procedure only samples the mucosa it is possible to miss detecting a tumor that involves only the deeper layers of the intestinal tract. In these unusual cases, the biopsy results are normal yet the dog continues to experience clinical signs. In order to reach a diagnosis in these cases, full-thickness biopsies obtained through an exploratory surgery, (exploratory laparotomy) or non-invasive tests such as an MRI (Magnetic Resonance Imaging) may be required.