What is Colitis in Dogs?


You have just adopted a new dog from your local animal shelter. Cooper has a great personality, loves your kids and seems to be settling in nicely to your home and daily routines. However, this morning Cooper asked to go outside several times. You notice that he is experiencing a loose stool and has been straining to defecate. You call your veterinarian, and she tells you that Cooper may have colitis.

What is Colitis?

Colitis is a general term for irritation or inflammation of the colon (large intestine). There are several forms of colitis in dogs, and these are typically classified according to the region of the colon and the type of intestinal cells that are affected. In addition, signs of colitis may occur acutely (over just a few days) or chronically (coming and going over a period of weeks or even months). Several common causes of colitis in dogs include:

  • Stress. For reasons that are not completely understood, dogs that are exposed to stressful situations, such as boarding at a kennel or shelter, traveling to dog shows, or being adopted into a new home, may develop acute colitis. Although its onset can be very sudden, stress-related colitis usually lasts just a day or two and resolves when the source of the stress is reduced.
  • Dietary indiscretion. Dogs who raid the garbage or scavenge items that they find when out walking can develop acute gastritis (stomach upset) that may be accompanied by colitis. Although most episodes are minor, signs can be severe depending on what type of food (or non-food) the dog consumed.
  • Intestinal parasites or infection. Certain parasites, such as whipworm or Giardia, and bacterial or viral infections can cause a variety of gastrointestinal signs, including colitis, in dogs.
  • Inflammatory bowel disorders (IBD). These are a collection of large bowel (intestine) disorders that have several underlying causes. In each specific disease, a different type of inflammatory cell increases in number in the intestine. Veterinary diagnosis is made by endoscopy and biopsy of the intestinal wall or by exploratory surgery. While usually not curable, colitis caused by IBDs can often be successfully managed through medication and diet.
Signs of Colitis in Dogs

Clinical signs of colitis are caused by irritation and inflammation to the cellular lining of the colon. This leads to abdominal discomfort, increased defecation frequency, and the production of bloody or mucus-containing diarrhea. Dogs may ask to go outside often to eliminate and show prolonged squatting and straining. (Note: This behavior can lead owners to mistakenly think that the dog is constipated.) Vomiting is uncommon with colitis but is seen in some cases. Dogs with chronic colitis often remain active, have a normal appetite and do not lose weight.

When to Contact Your Veterinarian

Because there are a variety of causes, whenever you see diarrhea or other signs of colitis in your dog, it is important to seek veterinary advice. Your veterinarian can make a diagnosis based upon a complete medical history, fecal exam and blood tests. In some cases, an endoscopy or biopsy may be necessary. Treatment is dependent on the underlying cause and type of colitis and may include antimicrobial medications, anti-inflammatory drugs, parasitic treatment and/or dietary management. Medications that modify colon motility may be prescribed for immediate relief and control of signs.

Tips for Preventing Colitis

  • Reduce stress. Prevent or minimize your dog’s stress by gradually introducing new experiences, other pets or lifestyle changes. Socialize and train your dog regularly to enhance his tolerance for new experiences.
  • Check for parasites. Provide regular fecal samples to your veterinarian to examine for the presence of intestinal parasites. Deworm as needed.
  • Feed a well-balanced diet. Ensure that your dog is fed a high-quality and well-balanced food. Prevent your dog from raiding the garbage and from scavenging while outdoors. Train a reliable response to the command “leave it” to prevent scavenging behaviors while out walking together.