Causes of Intestinal Obstruction in Dogs

The intestinal tract is the main set of organs responsible for digestion and nutrient absorption. For a dog to absorb the nutrient from the food they eat, it has to go down the entire length of the gastrointestinal (GI) tract, from the stomach to the end part of the intestines. Ingested food undergoes digestion and absorption processes as it moves down along the intestinal tract. Intestinal obstruction in dogs is a serious medical condition that can be fatal if not detected early or treated properly.

Signs of Intestinal Obstruction in Dogs

Intestinal obstruction in dogs has very generalized symptoms at the initial stages of the condition. This makes detection and diagnosis a little more difficult. Initial signs include loss of appetite, generalized weakness, abdominal pain, and vomiting.

If left undetected for an extended period, signs progress to severe weakness and lethargy, excessive vomiting often with foul-smelling vomitus, dehydration, and eventually shock due to fluid and electrolyte imbalance.

It’s important to detect early signs of possible intestinal blockage so that supportive treatment can be immediately given to prevent the condition from becoming worse or even fatal. If your dog is showing early signs of possible obstruction, there are several ways to diagnose and confirm if he is indeed suffering from it.

Common Causes of Intestinal Obstruction in Dogs

The most common cause of intestinal obstruction in dogs is the ingestion of foreign bodies or non-food materials. A dog’s behavior of chewing and swallowing various things puts them at a high risk of developing a foreign body obstruction. Dogs presented to a veterinary hospital with initial signs of intestinal obstruction often have a history of chewing on various things such as toys, shoes, and other common household items.

Certain food ingredients can also cause intestinal blockage in dogs. Fruits like mangoes and avocados have large and hard pits that, when swallowed, can lodge and get stuck along the intestine and cause obstruction. Corn cobs are also a common cause of obstruction in larger dogs.

Eating poorly digestible things such as grass or plants can obstruct if it accumulates along the GI tract. Linear foreign bodies such as dog leashes or ropes can also cause intestinal obstruction if swallowed.

Other possible causes of intestinal obstruction in dogs are motility problems leading to various changes in the intestine’s shape and position inside the dog’s abdomen. Food travels down from the stomach to the intestine through peristalsis, a segmental contraction of the intestinal wall. Changes in the rate of peristalsis in different segments of the intestine can cause one part to “telescope in” towards the following segment, causing intussusception. This condition obstructs the flow of food down the intestine and subsequently causes intestinal blockage in dogs.

Herniation of a portion of the intestine can cause stricture in the lumen and is also another possible cause of obstruction in dogs. Most hernias in dogs are congenital but, in some cases, it happens as a postoperative complication in abdominal surgeries. Growths along the intestinal wall, such as intestinal polyps and tumors, can also cause obstruction if they become big enough to block the entire intestinal lumen.

How are intestinal obstructions diagnosed in dogs?

When a dog is presented to a veterinary hospital with signs of possible intestinal obstruction, a thorough physical exam is the first step in trying to confirm the condition. If the blockage is big enough, be it either a foreign body or a tumor, it can be felt by palpating the abdomen of the dog.

Diagnostic imaging like radiographs (x-rays) helps confirm if the dog is suffering from an intestinal obstruction. Some foreign bodies are visible in radiographs and can easily be identified, but some materials do not take up x-ray radiation and are not radiographically visible. Changes in the shape and size of the intestine in the radiograph can suggest the possibility of obstruction but are not confirmatory alone.

If radiographs are not conclusive, a contrast study is often the next step in diagnosing intestinal obstruction. Your vet will administer a dye solution orally and will take a series of radiographs as the dye travels down the entire intestinal tract. If the dye is unable to reach the end segment of the intestine and stops at a certain point, it’s considered confirmatory for intestinal obstruction.

Partial obstructions are more complicated to diagnose since they often only show subtle signs of blockage even in diagnostic imaging tests. In some cases, an endoscopic exam can provide real-time visualization of the intestinal lumen and can confirm if there’s any partial obstruction anywhere along the intestinal tract.

What are the treatment options for dogs with intestinal obstructions?

Once confirmed, intestinal obstruction is treated accordingly depending on the cause. Oftentimes, surgical intervention is needed to remove a foreign body causing the obstruction or correct strictures, intussusceptions, or hernias. Aggressive supportive therapy is needed before, during, and after surgical procedures to reduce the risks of complications and address secondary dehydration and electrolyte imbalances that can go with the condition.

The success of the surgery and treatment is highly dependent on the health status of the patient when the obstruction is diagnosed. Early detection and appropriate surgical intervention often result in good recovery after surgery. Dogs that are showing chronic and severe signs of illness at the time of diagnosis often have poor prognoses even if appropriate treatment and surgical correction or intervention is done. In severe and chronic cases, a segment of the intestine may become non-viable and must be removed, which increases the risks of post-operative complications.

Intestinal growths, if solitary, can also be removed surgically. For cases of multiple intestinal tumors, proper identification of the tumor via endoscopic biopsy is needed and subsequent medical management such as chemotherapy will help reduce the sizes of the tumors and address the obstruction.

When to Visit the Vet

Visit your vet immediately if you start to see signs of possible obstruction in your dog. The key to successful recovery is early detection and immediate supportive and corrective treatment.

Read more:

Everything You Need to Know About Vomiting in Dogs

Help! Why is my dog vomiting blood?

Stomach Ulcers in Dogs and Cats

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