Gastrointestinal blockage (GI Foreign Body Obstruction) in Dogs

Most of the time when an otherwise healthy dog starts vomiting but shows no other symptoms, the vomiting resolves on its own within 24 hours. A foreign body or blockage isn’t usually suspected until a dog continues to vomit for more than 24 hours or develops other more alarming symptoms.

The symptoms of gastrointestinal blockage vary depending on how long the blockage has been present, whether the blockage is complete or partial, and what material the object is made of. In addition to the impact on nutrient absorption and ability to eat and digest food properly, GI obstruction has the potential to cause severe secondary conditions if left untreated.

Large foreign bodies put pressure on the intestinal wall, causing loss of blood flow to the area. In these cases, the tissue may leak as it breaks down and dies. A linear foreign body like a string can saw through the intestines while they contract around it. With time, the intestinal wall ruptures and leaks intestinal contents into the abdomen. This leads to highly fatal complications like peritonitis and sepsis.

Dogs with these symptoms require immediate veterinary attention.

Some foreign bodies are made of toxic materials. Coins, golf balls, and lead shotgun pellets are the most common toxic foreign bodies reported in dogs. As the stomach acid digests the item, it releases the metals within the object for absorption by the intestinal tract. This results in either lead toxicity or zinc toxicity.

Partial obstructions typically have less severe symptoms than complete blockages. Symptoms often come and go as the blockage improves or worsens over time. A dog with a partial blockage may vomit and refuse to eat for a day, then be back to normal for a few days before the symptoms return.

Dogs are prone to eating non-food objects, particularly young puppies. Many objects pass on their own, but some become lodged in the intestinal tract and obstruct the flow of intestinal contents. Such a blockage is life-threatening, so dogs known to have eaten an object must be watched closely for any changes. If the object clearly and obviously passes in the stool, there is likely no further cause for concern. If symptoms such as vomiting, abdominal pain, and lack of appetite develop, the dog requires veterinary attention. With prompt treatment, most dogs recover completely with a good prognosis.

Ingestion of non-food objects is the most common cause of gastrointestinal blockages. Most objects that cause blockages cannot be rapidly digested or are too large to pass through the gastrointestinal system, such as:

• Plastic
• Rocks
• Bones
• Toys or balls
• Corn cobs
• Clothing or shoes
• Jewelry

Small objects or linear objects are also problematic. Often, small objects cause partial obstruction or off-and-on obstruction as they move down the gastrointestinal tract. Additionally, when consumed in large amounts, tiny objects like hair elastics can effectively block the digestive tract. Linear objects such as string, yarn, and ribbon are prone to lodging at the exit of the stomach, and uncoiling down the length of the intestine. With the string fixed in place, the intestine begins to bunch up around the string, causing significant intestinal damage and blocking the flow of food.

Other causes of gastrointestinal blockage include parasites, tumors, bacterial or viral infections, and alterations to the intestinal tract preventing normal flow. These causes are much less common than foreign bodies in dogs.

Note that vomiting in cases of GI blockage are often severe but not always. Bowel habit changes may also occur, including no bowel movements at all. In some cases diarrhea may occur. Dogs showing signs of abdominal pain require prompt veterinary care.

Diagnosing gastrointestinal blockages is often challenging - unless the dog is known to have eaten an object- because so many different conditions lead to vomiting and appetite loss.

Diagnostic imaging provides a straightforward diagnosis in some cases, particularly when the object is made of metal, bone, or mineral (like a stone).

Other diagnostic testing includes:

• Blood work
• Abdominal ultrasound
• Barium/contrast studies
• Exploratory surgery

Surgical intervention is both a diagnostic test and a treatment. If a foreign body is strongly suspected, but cannot be confirmed, exploratory surgery allows the entire intestinal tract to be examined. At the same time, the foreign body is removed, resolving the issue.

Some foreign bodies resolve on their own when the dog either vomits the object spontaneously or passes it uneventfully. Most dogs have a good prognosis with prompt treatment, as long as more severe conditions such as tissue death and peritonitis have not developed.

Treatment of gastrointestinal blockages is somewhat dependent on the location of the blockage. Endoscopy is one option for removal of objects in the stomach or first segment of the small intestine. In this treatment, a long tube with a camera and a set of forceps is passed into the stomach. The forceps grasp the object and pull it out through the mouth. Endoscopy is not always available or suitable for all types of foreign body removal.

Foreign bodies identified in the lower intestines may be monitored to see if they are progressing on their own. If diagnostic imaging shows the object does not pass completely within 36 hours, or remains in the same location for more than 8 hours, then surgery is required. Surgical intervention involves opening the abdomen, locating the foreign body, and cutting through the intestinal wall to remove it. In some cases, a portion of the intestine is removed because of extensive tissue damage or death.

Even under the best of circumstances when the obstruction is small and identified early, surgical removal is still a complicated process. Affected dogs often develop electrolyte imbalances and are at increased risk for infection and shock prior to diagnosis, which affects their odds for a good surgical outcome. Cases presenting with peritonitis or sepsis in addition to the obstruction have a guarded prognosis and require aggressive treatment.

In some cases, the affected parts of the stomach or intestines are damaged to the extent surgical removal is necessary. This makes the surgery itself much more lengthy and difficult and increases the likelihood for post-operative complications. When a large portion of the intestine is removed, short-bowel syndrome due to inadequate nutrient absorption results. Affected dogs have a guarded prognosis.

GI obstruction in dogs is best prevented by supervising dogs and intervening before a large non-food item is swallowed. Diligent storage of human food and food waste combined with consistent training of young dogs can help prevent ingestion of items that have the potential to cause intestinal blockages. Ensuring dog toys and treats are appropriate for a dog’s size and play behavior are also effective strategies to avoid GI obstruction.

GI obstruction is common in dogs. Young puppies are particularly prone to eating foreign objects, and some individual dogs are more likely than others to make a habit of ingesting non-food items.

• Surgery
• Endoscopy