Intestinal Disorder (Loss of Motility) in Dogs

Motility in relation to the gastrointestinal tract refers to the ability of food and digested material to move smoothly from one end to the other. A loss of motility or obstruction can occur at any point. Since the channels of the small intestine are smaller, this is a common place for smaller objects or indigestible material to become stuck. Loss of motility in the intestines is called ileus. It results in irregular or difficult defecation, sometimes with other symptoms such as vomiting or abdominal distention. In dogs, this condition is often due to a physical obstruction. It may also occur after abdominal surgery, or as the result of a metabolic condition which affects the nerves and muscles of the digestive tract. Even conditions like this will result in some degree of physical obstruction, as obstipation (hardening of unpassed feces) further blocks the colon. Most problems are reversible with medical treatment or surgery depending on the cause.

Dogs can sometimes experience difficulty passing regular bowel movements. Veterinarians define this condition as ileus or loss of intestinal motility. It has a variety of causes, most of which are treatable.

Straining to pass feces is never a good sign. The longer the time between bowel movements, the harder the stool will become, and extreme untreated constipation will eventually be fatal. You should see a veterinarian as soon as possible if you notice any of the following symptoms in your dog:

• Struggling to have a bowel movement
• Reluctant to have a bowel movement
• Constipation
• Thin ribbon like stool
• Absence of intestinal noise
• Vomiting
• Signs of abdominal pain
• Abdominal distention
• Weight loss
• Lack of appetite
• Palpable lump of unpassed fecal matter in the abdomen

Types 

Loss of intestinal motility generally falls into one of two categories:

• Mechanical – blockage created by physical obstruction
• Functional – nerve failure or weakness in the bowel muscles

In dogs, physical blockage is generally more common due to their tendency to eat indigestible objects such as bones, fur, or even toys.

Many different problems can decrease intestinal motility:

• Difficult to digest material (such as bone or hair)
• Not drinking enough water
• Foreign body
• Tumor
• Stricture – constricted or thickened band of intestinal muscles
• Recent surgery
• Poorly healed fracture
• Enlarged prostate gland
• Drugs including opioids and antihistamines
• Poisoning
• Metabolic disorder - hypothyroidism, hypokalemia, and hypercalcemia
• Dysautonomia – neural degeneration disease
• Lesion on the spinal cord
• Idiopathic (unknown cause)

The veterinarian will perform a physical examination. In many cases, hard unpassed feces can be felt in the abdomen during examination. The veterinarian will likely also take an X-ray or ultrasound of your dog’s abdomen to check for a foreign body. Many objects can be detected on a radiograph; even if the object itself is not visible, increased dilation of some intestinal loops may indicate its presence. X-ray’s may also show tumors, strictures, and other abnormalities. If the object is difficult to detect on a radiograph, exploratory may be necessary.

As well as evaluating physical obstruction, the veterinarian will take bloodwork to look for metabolic abnormalities. This will show conditions such as hypothyroidism or hypokalemia, and may further indicate the presence of cancer if the radiograph is inconclusive. For serious constipation with no obvious cause, the veterinarian will also evaluate nerve and motor function with an emphasis on areas of the spinal cord which control the bowel muscles.

The exact symptoms that your dog is exhibiting may help to indicate the cause. Keeping a careful record of your dog’s bowel habits may aid the vet in ascertaining if there is a serious problem. If you’ve noticed your dog eating anything unusual lately, or chewing on small toys this could also be relevant. The veterinarian will also want to know your dog’s medical history and the dates of any recent surgery.

Mild constipation will likely be treated with medication and diet change. Various laxatives or suppositories are available, and the veterinarian will determine the one most appropriate for your dog. A fiber supplement may also be added to your dog’s diet. For mild post-surgery ileus, or poor diet and lack of fluids, this will often be effective. Long term, severe constipation can lead to dehydration so the vet might need to treat this with medication or IV fluids.

 If there is a sign of physical obstruction from a foreign body, tumor or stricture, this will require surgery. Badly healed fractures can sometimes also be corrected with surgery. There is a certain amount of risk with any surgery, but foreign body removal is usually successful. If there is a tumor it will depend on the degree of metastasis. Your dog will likely need to spend several days after surgery in the hospital and there will be a 2 to 3 week recovery period after he returns home.

If the condition was caused by a metabolic imbalance, your dog will need medication for this as well as laxatives to clear the blocked stool. The veterinarian will try to find the underlying cause for the condition. This could be due to poor nutrition, glandular dysfunction, or cancer. 

If a degenerative neural problem is causing your dog’s ileus, this may also be treated or ameliorated with medication. The prognosis for this kind of condition is not usually good, however.

The chances for recovery from ileus are high, depending on the severity of the condition and the length of time it has progressed. Most laxatives will be discontinued once your dog has started to have regular bowel movements, but if problems recur, long term medication could be necessary. The vet may recommend a different brand of dog food, or you may need to continue fiber supplements.

Most foreign objects are removed surgically without any recurring problem. It might be advisable to monitor your dog’s access to small objects which can be swallowed, if possible, to avoid any future problems. Your dog will need several post-surgery check-ups for monitoring, but otherwise he should be fine.

If the vet discovers that your dog’s loss of motility was due to another underlying disease this may pose more of a problem. Cancer can often be fatal, and neural degeneration diseases usually eventually require euthanasia. These conditions are rare however, and most forms of constipation are treatable.