The most common symptom of a blockage caused by a foreign object is vomiting. Dr. Sheila McCullough, a veterinarian at the University of Illinois Veterinary Teaching Hospital in Urbana, says, "Instead of vomiting once or twice, the animal may vomit ten times in a day. If the animal vomits every time it drinks water, this may indicate an intestinal blockage."
Dr. McCullough warns, "Unfortunately, the problem may not be that straightforward. Sometimes the object causes only a partial blockage, which means that some food and water will continue to move through the system." The object may also move but get stuck periodically, which means that the signs may not be consistent and vomiting may not occur every time the animal eats or drinks.
The object could be in the animal's intestine for a long time before it is discovered. Dr. McCullough says, "In my experience, the longest amount of time that an animal had a foreign object in its digestive system was 3 months!"
The main way to diagnose an obstruction is by taking radiographs (X-rays) of the animal's abdomen. Veterinarians look not only for the object itself but also for abnormal areas of gas in the intestine. Sometimes the object will not show up well on the radiograph, but if abnormal gas patterns are observed the veterinarian may give the animal barium, which is like a "white dye" that is given orally and coats everything in the stomach and intestine. An object coated with barium will appear white in radiographs.
Once a foreign object obstruction has been diagnosed, the foreign object may be removed by surgery or with an endoscope, an instrument with a tiny camera and grasping tool inserted into the body through the mouth without surgery. Sometimes a foreign object can damage the intestine, so a section of the intestine has to be removed. Sharp objects may perforate the intestine, causing further complications, and something like string can cause the intestine to bunch up like an accordion. If this occurs, friction can cause the string to cut into the intestine like a saw, making many small perforations that must be repaired by the surgeon. If the intestine has been perforated, fluid from the intestine may have leaked into the abdomen, which can cause a serious infection called septic peritonitis. Dr. McCullough says, "All of these possibilities make recovery time for an animal that has just had a foreign object removed quite variable."
