Gastrointestinal (GI) obstruction is a general term for a blockage anywhere along the GI tract. The causes range from a hairball that's plugging up the intestines to a tumor that's grown large enough to obstruct the rectum.
Think of the gastrointestinal tract as a long tube, running from the mouth to the esophagus, the stomach, the small and large intestines, the rectum, and ending at the anus. A blockage can occur anywhere along the GI tract. Not only will food and water be unable to pass, but the obstructed area can actually burst. Without prompt treatment, this can cause severe infection and death.
Risk factors and detection
The risk factors depend on the cause of blockage. Causes include:
Foreign body obstruction. This condition occurs in dogs who eat bones, rocks, sticks, toys, clothing, and other household items that can clog the GI tract. Puppies tend to be less discriminating eaters.
Dogs may experience this problem after ingesting lengths of rope or pantyhose. Part of the foreign body sits in the stomach, and the remainder snakes down the intestines, causing the bowels to fold up like an accordion. This type of foreign body can actually cut through the intestines.
Pyloric stenosis. This condition is a narrowing of the outlet from the stomach into the small intestines. It occurs when the stomach grows so thick that the sides come together and block the outflow, causing chronic vomiting. This condition usually appears by 1 year of age in Boxers, Bulldogs and Boston terriers and is twice as likely to affect males than females. An acquired form can occur around 10 years of age in Lhasa apsos, Shih Tzus, Poodles, and Pekingese.
Cancer of the GI tract. Cancer can gradually cause signs of obstruction, such as anorexia, weight loss, vomiting, and diarrhea, as the tumor blocks the tube. It generally occurs in middle-aged to older dogs.
Gastric dilatation-volvulus (bloat). Bloat is a condition in which the stomach twists, obstructing the esophagus and the stomach. Bloat affects any breed of dog, but large, deep-chested breeds (such as Great Danes) are more susceptible.
Intestinal parasites. A large burden of roundworms in the intestines can cause an obstruction, especially in puppies.
Intussusception. This condition, in which a segment of the GI tract telescopes up into another segment, occurs mostly in dogs less than 1 year old. Male German shepherds have a higher risk of developing an intussusception in which the stomach slips into the esophagus.
Hernia. This obstruction occurs when a portion of the GI tract slips through a hole in the abdominal body wall and becomes trapped.
Blocked feces. A number of conditions cause blocked feces in the rectum or at the anus. If the large intestine is dilated, a condition known as megacolon, it can retain too much feces. In older, unneutered male dogs, an enlarged prostate can push up from below the rectum and cause an obstruction. Or in longhaired dogs, hair and feces can mat around the anus, preventing defecation.
Signs of GI tract obstruction may vary, depending on the type of obstruction. They may include:
- drooling
- vomiting
- dry heaving
- appetite loss
- straining to defecate
- diarrhea
- lethargy
- weight loss
- abdominal pain
- abdominal enlargement.
GI tract obstruction is very serious, so if you have any concerns, take your
dog to your veterinarian immediately.
After carefully examining your dog, the doctor may need to perform blood tests to determine the severity of your dog's condition. X-rays and ultrasound can help identify the problem and determine potential treatment options.
Prevention and treatment
To prevent ingestion of foreign bodies, keep household items picked up and out of your dog's reach.
Also, ask your veterinarian to deworm your puppy to eliminate harmful worm burdens. For longhaired dogs, keep their tail area clean and trimmed. If your dog is prone to bloat, feed her two or three small meals a day instead of one large meal, and hold off on exercise for an hour after feeding.
Treatment depends on the cause and location of the obstruction. Affected dogs usually require intravenous fluids to correct dehydration and antibiotics for GI tract infection.
Your veterinarian may be able to retrieve some foreign bodies using an endoscope, but most obstructions, including tumors, require surgery. Dogs with tumors also may need chemotherapy or radiation therapy.
Your veterinarian will use an enema to alleviate a fecal impaction, or he or she may need to anesthetize your dog and manually remove the blockage. If hair and feces are matted to the anus, gently cleaning away the mat will allow defecation.
