​Dog Constipation: Causes, Diagnosis & Treatment

Constipation refers to an inability to produce normal stools on a regular schedule, which, for a dog, is generally once or twice per day. Dogs who are suffering from constipation will not “go” at all, strain to defecate, or produce rock-hard stools.

In chronic cases, dogs may retain hard, dry fecal matter in their digestive tracts. This is known as obstipation, in which there is so much fecal matter that it becomes compacted and the dog cannot defecate at all.

What Are the Signs of Dog Constipation?

The signs of constipation are pretty obvious, including:

  • Lack of defecation for a few days;
  • Hard, dry stools that feel like pebbles when you pick them up.

Two other signs of discomfort are associated with constipation, including:

  • Tenesmus, which includes straining to defecate with little or no result, or producing small amounts of liquid fecal matter mixed with blood;
  • Dyschezia, which is painful or difficult defecation.


What Causes Constipation?

Under normal circumstances, fecal matter travels through the digestive tract, reaching the colon where water and electrolytes are absorbed from the mass. Water reabsorption is the colon’s main function.

Fecal material in the colon is moved through a process known as “peristaltic waves.” If this process becomes impaired or slowed, the fecal mass will stall in the colon and continue to lose moisture, becoming hard, dry, and, ultimately, impossible to pass.

Scientists have long used a term usually associated with geology—“concretion”—to describe stool that is as hard as a rock.

Most Common Causes

Veterinary textbooks list scores of underlying causes, some as benign as lack of exercise, others much more serious problems, like cancer. Veterinarians categorize these causes, based upon where the problem occurs along the digestive tract. They use the words:

  • Interluminal (referring to blockages inside the colon)
  • Extraluminal (obstructions originating outside the colon, such as tumors or pelvic fractures)
  • Intrinsic (diseases and nerve injuries)

Some of the most common reasons dogs become constipated include:

  • Diet—As in humans, a diet lacking in fiber is often the problem. Also, unlike humans, dogs tend to eat things that are not food—like hair, toys, and kitty litter—and these may cause blockages and abnormal fecal transit. Bones, bone meal, and other sources of dietary calcium can contribute to constipation.
  • Age—Elderly dogs seem more prone to constipation.
  • Activity level—For reasons unknown, being sedentary often results in slower transit.
  • Digestive tract tumors
  • Tumors that narrow the pelvic region
  • Anal gland issues
  • Prostate enlargement
  • Dehydration or electrolyte imbalances
  • Drugs, including opiates, diuretics, antihistamines, some antacids, certain cancer drugs
  • Metabolic diseases, like hypothyroidism
  • Spinal diseases and injuries
  • Central nervous system disorders
  • Stress and psychological problems—Something in the environment that will lead a dog to hold it.
  • Orthopedic disorders that make it difficult for the dog to squat.
  • Surgery—Medical procedures, and the drugs administered during these procedures, may result in constipation. Call your vet for advice if you observe this in the post-surgical period.

What To Do If Your Dog Is Constipated

If the problem has just started—no more than a day or two—a few home remedies might get things moving again. Keep in mind that no one strategy works for all dogs. But some of the old-standbys for treating constipation include:

  • Pumpkin—Weirdly, this dietary fix works in some dogs for either constipation or diarrhea. It is high in both fiber and moisture, and many dogs like the taste, so they’ll happily take this medicine. There are several recipes for tasty pumpkin treats that dogs love, although for regulating the digestive tract it's probably best to give it straight.
  • Canned dog food—Elevated moisture content of canned food may help regulate the system.
  • Powdered fiber supplements
  • Food and herbs, such as ginger, wheat bran, powdered psyllium seeds, and olive oil, may help. A 2011 study, exploring treatments for constipation in humans, showed that fig paste was effective for treatment of constipation in their research colony of Beagles. Foods that help humans with the problem are likely fine for dogs, but it always is prudent to check with your vet.
  • Hydration—Make sure your dog has access to fresh water and maybe electrolyte supplements.
  • Exercise

When To Take a Constipated Dog to the Vet

It’s a good idea to call the vet as soon as you become aware of the problem. Constipation can be a sign of some very serious diseases.

Long-term or chronic constipation may lead to a buildup of dried fecal matter that gets stuck in the colon, known as obstipation. This may contribute to another condition marked by an inability to defecate normally —megacolon. The colon becomes distended and loses its ability to move feces along. Chronic constipation is both a contributor and a sign of this disorder.

When you visit the vet, make sure you come armed with as much information as possible, including:

  • The last time your dog had a normal bowel movement
  • Stool color and consistency
  • Changes in the dog’s diet or routine
  • Non-food items the dog may have eaten (this can include anything from bones to kitty litter)
  • Straining or pain while trying to go
  • Drug treatments
  • Injuries
  • Other signs of distress or discomfort, especially vomiting, lethargy, or a bloated appearance.

Depending upon the duration and severity of the symptoms, the veterinary exam may consist of:

  • Abdominal palpation
  • Rectal exam
  • Radiographs of the abdominal area
  • Barium enema
  • Ultrasound or colonoscopy
  • Complete Blood Count
  • Urinalysis
  • Neurological exam

Veterinary Treatment and prevention

Most cases will resolve with mild treatments, such as boosting liquids and dietary fiber or getting more exercise. Laxative suppositories and enemas may be helpful, but should only be used with guidance from a veterinarian, especially if they are needed for long periods.

More extreme cases will require such medical interventions as:

  • Manual removal of impacted feces
  • Drug to activate normal colon function or to block the production of certain enzymes.
  • Surgery may be needed in very rare, extreme cases, usually for megacolon. One surgical procedure is known as a colectomy, in which sections of the colon are removed.

For most dogs, constipation will be an infrequent problem, kept under control through a well-balanced diet, access to fresh water, and regular exercise.

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