• Jolene Seville
  • Dog Nutrition and Member Service Specialist

  • 3 mins read time
  • Dogs and Colitis

    Does your dog have occasional diarrhea with mucus or blood? Do they have a “sensitive” stomach when it comes to new foods? They may be experiencing colitis!

    What is Colitis ?

    Colitis is inflammation of the colon or large intestine that leads to pain, discomfort, and diarrhea. It can be either acute (sudden) or chronic (long term). Acute cases are more common, and most dogs will have colitis at some point in their life. It is important to understand what is causing it in your dog. Correcting symptoms will make you and your dog feel better in the short term, but unless you get to the root cause, it may come back at a later date.


    There are two types of diarrhea dogs may experience -small intestine and large intestine. The different symptoms will help you identify if your dog is actually experiencing colitis.

    Small Intestine

    Diarrhea from the small intestine is not colitis, but it can be serious and may also be a symptom of something bigger such as parasites, endocrine diseases or renal disease. You should speak with your vet if symptoms persist more than 48 hours.

    • Often higher volume and stronger smelling than normal bowel movements

    • The dog will likely not poop any more frequently than their normal schedule

    • Likely to be very watery

    Large Intestine

    Diarrhea from the large intestine would be considered colitis. While some of the symptoms may seem alarming (blood), it is often not a serious problem.

    • Smaller volume

    • More frequent

    • Usually a sense of urgency and often leads to accidents

    • May contain bright red blood and/or mucous.


    Most cases of colitis are ulcerative (inflammation and small ulcers in the large intestine. It is extremely common and there isn’t one single thing that will cause a flare up. Here are the main contributing factors:

    • Stress - Some dogs will experience colitis as a result of a stressful situation such as boarding, flying on a plane, or a long car ride. Stress is the most common cause of colitis. While vets can’t pinpoint exactly why this happens, they theorize it has to do with the weakening of the immune system and putting more stress on the body and digestive tract as a whole.

    • Abrupt change in diet - This can include switching to a new food cold turkey, introducing raw items too fast to a kibble fed dog, or a dog eating something not intended for them. Garbage, food scraps, overeating and excess fatty foods can all cause colitis.

    • Infections - Salmonella, E. Coli, and other bacterial infections often have colitis as a symptom. These are generally not life threatening as dogs have the appropriate enzymes to process pathogenic bacteria.

    • Parasites - Giardia and worms can cause persistent diarrhea.

    In rare cases the cause can be granulomatous colitis, which is a type of Crohns disease that affects (typically young) boxers and french bulldogs. This is unlikely to be the cause of your dog’s issues but if it is a boxer or french bulldog it wouldn’t hurt to check with your vet.

    Diagnosis and Treatment

    Treatment for colitis will vary depending on the dog, severity of the diarrhea, and the cause.

    Acute and Mild Colitis

    For most dogs it will be minor discomfort and diarrhea caused by stress or diet change and a vet visit and formal diagnosis won’t be necessary. Mild cases will clear up on their own, usually within 24-48 hours. Here are a few ways you can help your dog get back to normal.

    • Fasting for 24-48 hours to give the digestive system a break and ease inflammation. Be sure to provide plenty of fresh water to prevent dehydration.

    • After fasting, feeding a bland diet can be a gentle way to reintroduce food. If you prefer to not fast at all or if you have a dog under 1 year, a bland diet will also be gentle on their already upset stomach. Be sure to avoid the traditional chicken and rice in favor of something gentler and non-inflammatory like turkey and pumpkin. Once the stool returns to normal you can slowly reintroduce their normal diet.

    • Feeding a dietary fiber like psyllium, larch or slippery elm will help absorb water in the colon and create solid bowel movements. The mucilage in slippery elm will also help soothe the mucus membranes and reduce inflammation.

    Chronic or Serious Colitis

    For more serious or chronic cases, a vet visit will be needed to rule out bigger issues. If your dog is not drinking, their stool is not improving after 24-48 hours, or you suspect parasites or infection, you should check in with your vet.

    Your veterinarian will review what your dog’s diet is like and whether or not they have a history of colitis. They will also ask about any recent changes or stressors in their life or anything you feel may be the issue. Speak up even if you think it may be irrelevant.

    A physical examination and fecal tests will be done. Your vet will likely test for parasites, bacterial and fungal infections or perform a colonoscopy.

    For infections or parasites, your vet will prescribe appropriate medication. If your dog is put on antibiotics be sure to add probiotics to their diet to help keep the digestive tract healthy, as antibiotics can kill healthy bacteria in addition to the harmful ones!

    After a vet diagnosis, be sure to ask follow up questions. For example: If it was parasites or an infection, what steps can you take to prevent it from recurring? Are there any potential side effects of the medications you should look for? Is your dog now predisposed to more colitis episodes.


    It is very likely that at some point in your dog’s life it will experience colitis. While you probably can’t avoid it entirely, there are a few things you can do to help prevent flare ups.

    • Teach your dog to “leave it” or “drop” on command. You can help prevent digestive upset by not allowing your dog to eat food on the ground, garbage or anything else not intended for them.

    • Introduce new foods slowly. It is always best to introduce a new food item gradually to allow the stomach time to adjust. A kibble fed dog will have a lower stomach pH making it a challenge to fully digest raw items. Even switching from one food to another can be a shock to the system and cause colitis. When in doubt, slower is always better.

    • Add fiber. If your dog has frequent digestive issues and your vet hasn’t been able to give you a specific diagnosis, adding fiber to their regular diet may help. Pure pumpkin puree can be fed daily if your dog needs a fiber boost. Slippery elm can be a great way to prevent and treat digestive issues. When fed before introducing new items it can help keep poops firm and prevent inflammation. It can also be fed after your dog has ingested anything you think may cause diarrhea based on past experiences.

    • Prevent parasites. Research your area and be aware of what potential parasites can infect your dog. This may mean giving oral preventatives if you’re in a high risk area. Talk with your vet about what is most common and how you can be proactive.

    Colitis can seem scary in the moment. Seeing blood in the stool makes even the most experienced pet parents worry. Just remember, it’s extremely common and usually the body’s normal reaction to stress or diet changes. By keeping some slippery elm on hand and always being careful with what and how much you feed, you can give yourself some peace of mind. Get familiar with your dog’s digestive system as well. When you know what is normal for your dog, you’ll know when something is a cause for concern.