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Home > Dogs > Colitis in Dogs: Signs, Causes, and Care Guide (Vet Answer)

Colitis in Dogs: Signs, Causes, and Care Guide (Vet Answer)

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Dr. Marti Dudley

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If your dog is experiencing diarrhea with a sense of urgency, it is possible that they are experiencing colitis. Bacteria, viral, and parasitic infections can all initiate a case of colitis. Other causes are possible too, including stress. Fortunately, colitis is treatable with appropriate intervention. Continue reading to learn more about the common canine medical condition referred to as colitis.


What Is Colitis?

Colitis is simply the inflammation of the last portion of the gastrointestinal tract, referred to as the colon. As a review, food enters the stomach from the esophagus. From here, ingesta makes its way into the small intestines (consisting of the duodenum, jejunum, and ileum), prior to entering the large intestine, more commonly referred to as the colon. The colon is responsible for water absorption. In cases of colitis, inflammation of the colon leads to poor water absorption. This is what causes the loose, watery stool and the urgency to defecate.

Colitis can be acute, lasting only a few days, or chronic when occurring for greater than 2 weeks.

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What Are the Signs of Colitis?

Dogs struggling with colitis may experience:

  • Watery to partially formed diarrhea
  • Increased urgency to defecate
  • Blood in stool
  • Dehydration
  • Mucus in stool
  • Small, frequent defecations

What Are the Causes of Colitis?

There are numerous causes of colitis in the dog. Certain illnesses are more likely to cause chronic colitis than acute colitis. Your dog’s history will help your veterinarian determine the underlying cause of their signs.

Causes of Acute Colitis

  • Viral, bacterial, or parasitic infections
  • Dietary Indiscretion
  • Stress

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A Special Note on Stress Colitis

For dogs and people alike, when stress occurs, the signs are often noticeable originating in the gastrointestinal tract. Stress colitis is one of the most common causes of colitis and is often diagnosed in dogs in a boarding scenario. Colitis doesn’t only occur in boarding situations but can occur in any high-stress situation, including car rides, vacations, and a change in household dynamics.

Causes of Chronic Colitis

  • Food hypersensitivity
  • Neoplasia
  • Inflammatory bowel disease
  • Infection

Diagnosing Colitis in Dogs

If your dog is experiencing severe or ongoing diarrhea, an appointment should be scheduled with your veterinarian. Your veterinarian will perform a thorough physical examination and explore recent history. Based on your pet’s clinical signs, appropriate recommendations will be made regarding testing. In many cases, the first diagnostic recommended is a basic fecal test which screens for several gastrointestinal parasites.

Other tests include giardia antigen screening, bloodwork, and a direct fecal evaluation.

In complex or difficult-to-treat cases, there are panels available at reference laboratories that test for several of the most common infectious causes of diarrhea.

In chronic conditions or conditions not responding to typical interventions, a biopsy of the colon may be necessary. Biopsies are a way to identify inflammatory bowel disease, neoplasia, and certain types of infections.

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How Do I Care for a Dog With Colitis?

Your veterinarian will provide you with the tools you need to support your pet through colitis. A multimodal approach to colitis is typically helpful. First, an underlying cause should be identified, when possible, to better determine the appropriate treatment course.

In the event of a bacterial or parasitic infection, appropriate medications should be dispensed to eliminate the pathogen. A common antibiotic used in colitis is Metronidazole. If parasitism is diagnosed, there are several treatment options your veterinarian may recommend.

In patients experiencing colitis secondary to stress, care should be taken to lessen their anxiety. Often, supportive care is initiated in patients, regardless of the underlying cause. Fluid therapy is often recommended when dehydration has occurred. Additionally, probiotics may also prove beneficial.

Steroids may be necessary to reduce inflammation in the colon in chronic cases of colitis, which is seen in inflammatory bowel disease and allergic bowel disease.


Most cases of colitis will benefit from an adjustment in diet. Dogs with colitis secondary to stress or dietary indiscretion (i.e., too much people food, new diet, too many treats, consumption of food waste, etc.) may benefit from a bland diet with added fiber. This helps to improve stool consistency and puts less stress on the gastrointestinal tract. These diets may only be necessary in the short term.

In conditions like inflammatory bowel disease, a diet change to a hypoallergenic or hydrolyzed diet may be beneficial. In this situation, a feeding trial will be recommended to see if the diet improves your pet’s overall condition. If improvements are noted, your dog may need to be on this diet long-term.

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My dog is experiencing colitis and has been placed on a special diet by my veterinarian. Does my dog need to be on it for their entire life?

It is possible that your veterinarian has placed your pet on a specific diet temporarily to quickly improve the diarrhea. In some situations of food allergies or inflammatory bowel disease, a hydrolyzed or novel protein diet may be recommended. In that case, that food should be fed life-long if improvements are noted.

My dog has had their first bout of colitis; is this something that will continue to occur?

Not necessarily. Just because your dog has experienced colitis once doesn’t mean that this will become a continued battle. There are several different causes of acute colitis in dogs.



Colitis is a common condition that veterinarians treat in canine patients regularly. Although colitis is common, there are several different causes, each with a slightly different treatment course. Dogs with severe colitis are at risk of developing dehydration. It is critical that dogs receive treatment as soon as possible as colitis can be uncomfortable and contribute to stress in patients. Your veterinarian will be an asset to you as you work together to resolve signs of colitis in your beloved companion.

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