Dog Constipation: Causes and Treatment

Rachel Whitesell, DVM
Written by:
Published: April 5, 2022

When your dog isn’t pooping as much as they usually do, or at all, they are probably constipated. If they do poop, the stool will be small, hard, and dry, and it will be painful as your dog struggles to pass it.

Most dogs defecate 1-3 times per day, often after a meal. Normal stool is soft but still holds its form. Constipation is uncommon in dogs, but often easy to treat. It can also be mild or severe.

Severe constipation can lead to a condition called obstipation, in which defecation is impossible. Prolonged or repeated obstipation can lead to megacolon. In this condition, the muscles of the colon wall become permanently stretched and can no longer function properly.

Here’s what you need to know about constipation in dogs, from signs and causes to when you can treat it at home and when you need to go to the vet.

How Dogs Get Constipated

After your dog eats, the food enters their digestive tract. The main organs involved in digestion are the stomach, small intestine, and large intestine (also called the colon).

The colon is one of the last steps in the digestive process. It receives chyme (a mass of mostly digested food and digestive juices) from the small intestine, and then absorbs electrolytes and water from the mass as the feces travels toward the rectum. The mass is guided through the colon by natural lubrication and the rhythmic action of the colon wall muscles.

If the fecal material slows down as it travels, the colon will continue to absorb the salts and water from it. The result is smaller, drier feces that are more difficult for the colon to move forward, and your dog becomes constipated.

Signs of Dog Constipation

The easiest symptom to recognize is seeing your dog straining to defecate, but this can be easily confused with other problems such as diarrhea and having trouble peeing.

If you see that your dog can’t urinate, call an emergency vet right away, as this is a medical emergency.

As constipation becomes more severe, your dog may become lethargic, stop eating, or begin vomiting. If you see any of these signs, call an emergency vet right away.

Other signs of constipation include:

  • Scooting (dragging their bottom across the ground) due to discomfort

  • Swelling around the anus

  • Circling or pacing between episodes of straining

  • Vocalizing while trying to poop

  • Less frequent bowel movements

  • Passing small, hard pieces of stool that are sometimes foul-smelling and/or left in odd places (such as corners and basements)

  • Hunched appearance

  • Sensitive stomach (your dog won’t want you to touch it)

  • Passing a small amount of liquid with mucus and/or blood (caused by excessive straining)

Causes of Dog Constipation

The number one reason for constipation in dogs is eating things that are indigestible, which become lodged in the colon, preventing feces from advancing. Other reasons for constipation include:

Diet

  • Indigestible items (e.g., large amounts of fur, bones, litter, etc.)

  • Diet change

  • Low-fiber diet

Change in Household or Routine

  • Stress from boarding, traveling, new person or pet in home, new schedule for family members

  • Getting less exercise (e.g., recent hospitalization, change in mobility)

Grooming (matted fur over anus)

Pain That Hinders Pooping

Neurologic Conditions

  • Nerve damage

  • Tumors

  • Disc disease

Structural Obstruction

  • Prostate enlargement (e.g., inflammation, tumor)

  • Previous pelvic fracture

  • Intestinal stricture

  • Enlarged abdominal lymph nodes

  • Tumors of the rectum or anus

Systemic Disease

  • Hypothyroidism

  • Chronic kidney disease

  • Calcium and electrolyte abnormalities

Medications

  • Opioids

  • Antihistamines

  • Diuretics

  • Sucralfate (for ulcers)

How to Help Constipated Dogs

Your first instinct may be to try to solve your dog’s constipation at home. But in certain cases, your dog may need to see the vet. Here are some guidelines for getting your dog the right treatment.

When to Go to the Vet for Dog Constipation

Lethargy, decreased appetite, vocalizing, and vomiting are all signs of more severe cases. If you see these, call your vet and don’t try to manage the condition at home. 

If your dog has not had a bowel movement in 48-72 hours, it’s also time to call the vet. If it has not been at least 2 days yet, follow these steps:

  1. When you see your dog straining, check to make sure that your dog is able to urinate. It can be easy to mistake straining to urinate and straining to defecate. Not being able to pee is a medical emergency in dogs that should be checked out right away.

  2. Next, if your dog is able to poop, check the consistency of the stool to see if there is evidence of diarrhea. If you see diarrhea or a small amount of liquid with mucus or blood, contact your vet.

  3. Look at your dog’s rear end. Check for the following:

  • Redness, swelling, and/or open sores (signs of abscesses). If you see any of these, go to the vet right away.

  • Fecal matter or hair that may be matted over the anus. If you see this, soak the area well with warm water, and gently remove the feces. If possible, trim the fur to prevent further matting, and monitor for further signs of constipation or diarrhea.

When Can You Monitor Dog Constipation at Home?

After you’ve gone through the steps above, mild cases of constipation can be managed at home:

  • Try taking your dog on a long walk or more frequent walks. Exercise can stimulate the colon and may relieve constipation.

  • To increase hydration, try switching to canned food or adding water to kibble.

  • You can also add 100% canned pumpkin (not pie filling with other ingredients) or Metamucil to each meal. Canned pumpkin does not have as much relevant fiber as Metamucil or bran, but it is more readily available and can be sufficient for milder cases.

    • Canned pumpkin: Give 1-4 tablespoons per meal depending on the size of your dog. (1 TB for small breeds, 2-3 TB for medium breeds, and 4 TB for large breeds)

    • Metamucil: Contact your vet for the right amount for your dog.

Do NOT try any of the following:

  • DO NOT give mineral oil or white petrolatum to your dog. These unflavored items can be easily inhaled, leading to fatal aspiration pneumonia.

  • DO NOT use any over-the-counter enemas, unless specifically instructed by your veterinarian. Many common human enemas are toxic to dogs.

  • Giving your dog coconut oil or olive oil is also not recommended. Inappropriate amounts can lead to pancreatitis, bloat, vomiting, or diarrhea. Talk to your veterinarian first.

How Vets Diagnose What’s Causing Your Dog’s Constipation

During your visit, your veterinarian will perform a physical exam, including a rectal palpation (feeling the area with their hands). Based on the exam and your dog’s health history, they will likely be able to determine whether your dog is truly constipated.

Radiographs (x-rays) of the abdomen can confirm the diagnosis and severity. They can also help identify possible causes, such as ingestion of foreign material, previous pelvic fracture, enlarged prostate, or perineal hernia.

Your veterinarian may recommend further tests, especially if your dog becomes constipated often:

  • Bloodwork to detect dehydration, infection, thyroid abnormalities, and electrolyte disturbances

  • Urinalysis to detect infection or inflammation of the urinary tract and/or prostate

  • Abdominal ultrasound or colonoscopy to investigate masses and strictures within and around the colon

  • An MRI to scan for neurologic or structural abnormalities

Your veterinarian will discuss any further diagnostics based on your dog’s specific condition.

How Vets Treat Dog Constipation

For cases of mild constipation, your vet will give your dog fluids (if your dog is dehydrated) and then remove the feces. An enema that is performed by a vet is often effective in resolving mild constipation.

For more moderate to severe cases of constipation and obstipation, your dog may need to go under general anesthesia so your vet can manually remove impacted fecal material. The most severe, recurrent cases may require surgery to remove any non-functioning part of the colon.

As part of treatment, your vet may recommend adding a bulk-forming laxative to your dog’s regular diet once they are well-hydrated. Bulk-forming laxatives include products such as psyllium (Metamucil), bran, or 100% canned pumpkin. These absorb water and add volume to the stool.

Other medications often prescribed include a laxative called lactulose, which brings water into the stool to soften it; or a prokinetic agent, such as Cisapride, which stimulates the smooth muscle of the colon to move feces forward.

Constipation in Puppies

Constipation in puppies is not common, so a straining puppy will more likely have diarrhea.

Newborn puppies need to be manually stimulated by their mother or pet parent to urinate and defecate regularly. If they have structural anomalies in or around the intestinal tract from abnormal development, this can slow down the food or stop it from flowing through the digestive tract.

Large amounts of intestinal parasites can block a puppy’s intestines, as well as any material they may ingest. Puppies are far more sensitive to dehydration and lack of food than adult dogs, so their condition can worsen quickly.

If a puppy has any of the following symptoms, contact your veterinarian immediately:

  • Has not passed any stool in 24 hours

  • Is not eating

  • Is vomiting or retching

  • Appears to be in pain

  • Is lethargic

  • Has a distended belly

How to Prevent Your Dog From Getting Constipated

The best way to prevent constipation in your dog is to treat the underlying causes that your vet identifies.

This may involve thyroid supplementation, surgery to remove strictures or tumors, antibiotics, or pain management, for example. Any medications suspected of contributing to constipation should be changed or discontinued. Follow all instructions from your veterinarian carefully.

Work with your veterinarian to choose a well-balanced, easily digestible diet. A veterinary high-fiber diet or a veterinary low-residue diet (low in fiber and easy to digest) may be recommended.

Medications, including bulking agents, stool softeners, and/or prokinetics, will be prescribed and adjusted over time. Some cases require long-term medication administration.

Here are some other helpful tips for preventing constipation:

  • Closely monitor the frequency and consistency of your dog’s stool.

  • Ensure that your dog gets plenty of exercise daily.

  • Avoid dehydration by offering multiple sources of freshwater, or feed canned food to increase water intake.

  • Groom your dog regularly, keeping the fur around the anus short.

  • Avoid giving your dog bones or other undigestible items, and prohibit access to things that may cause constipation, including litter or clothing.

  • Other management options that may foster regular bowel movements and a healthy intestinal tract include a daily probiotic and acupuncture.

References

  1. ASPCA. People Foods to Avoid Feeding Your Pets.

  2. Birchard SJ, Sherding RG. Saunders Manual of Small Animal Practice. W.B. Saunders, Cop; 2006.

  3. Brooks, W. Veterinary Partner. Constipation and Megacolon in Dogs and Cats.

  4. Deforges, A. Merck Veterinary Manual. Constipation and Obstipation in Small Animals - Digestive System.

  5. Gfeller R, Thomas M, Mayo I. Veterinary Partner. Straining to Eliminate: First Aid.

  6. Rothrock K, Shell L. VINcyclopedia of Diseases. Constipation (Canine).

  7. Rothrock K, Shell L. VINcyclopedia of Diseases. Megacolon (Canine).

  8. Tilley LP, Francis, Sleeper MM, Brainard B. Blackwell’s Five-Minute Veterinary Consult. Canine and Feline. Wiley-Blackwell; 2021.

Featured Image: iStock.com/Vasil Dimitro


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