Any dog can develop colitis regardless of age, breed, or sex. This condition can happen suddenly (acute colitis) or it can be a chronic condition. Chronic colitis can occur as a result of another medical condition.
The term colitis simply means inflammation of the colon, also known as the large bowel. Since colitis typically causes diarrhea, it is sometimes referred to as large bowel diarrhea.
Dog colitis symptoms will vary depending on whether your dog has acute or chronic colitis.
Symptoms of colitis in dogs include:
• Increased flatulence
• Discomfort in the lower abdomen (usually caused by large bowel cramping or gas)
• More frequent, smaller volume, bowel movements
• Soft or runny stool (often contains mucus or red blood)
• Straining or pain with defecation (may look like constipation)
• Urgency in needing to go to the bathroom
Of course, diarrhea may be related to both the large and small intestines – it presents in different ways. Dogs with small bowel diarrhea are more likely to experience lethargy, vomiting and weight loss. If blood is present in the small bowel diarrhea, then it will appear dark (like coffee grounds or tar) – not fresh red blood as with large bowel diarrhea. But in cases of colitis, it is primarily the large bowel that is affected.
Two forms of colitis in dogs – Acute and Chronic:
Acute colitis (also referred to as stress colitis) refers to a sudden onset of symptoms that typically lasts only a few days, and it usually clears up on its own. It happens when stress and/or anxiety impede immune function – leading to inflammation of the large bowel. Stressful events like moving house, being sent to kennels or even loud noises like fireworks or thunderstorms can cause the development of acute colitis.
Dogs with acute colitis often have a sudden onset of diarrhea that ranges from soft stool to straight liquid. Their stool might also have some bright-red blood and/or mucus.
If your dog has acute colitis, they may have to urgently go outside multiple times and will sometimes go to the bathroom inside the house, despite being house-trained. They might appear to be straining to defecate as well. Vomiting can also occur, but this is not common.
Causes of Acute Colitis
• Dietary indiscretions (too many treats, eating people food, or getting into the garbage)
• Inflammatory bowel disease
• Intestinal parasites (such as worms)
• Irritable bowel syndrome
• Stress (moving house, boarding, traveling, or environmental changes)
• Sudden changes in diet
• Trauma to the GI tract
Chronic colitis lasts anywhere from weeks to months. With chronic colitis, dogs have multiple episodes of symptoms that keep coming and going, or symptoms that simply don’t go away. Either way, chronic colitis in dogs often requires a medical help.
Dogs with chronic colitis are typically healthy and seem fine but have soft stools that might contain blood or mucus.
Causes of Chronic Colitis
• Dysbiosis (leaky gut)
• Food allergy or sensitivity
• Foreign materials
• Idiopathic (when your vet is unable to define a specific cause)
• Infections of the GI tract (bacterial, fungal, viral – e.g. campylobacter, salmonella, or clostridium) or a fungal infection like histoplasmosis
• Parasites (e.g., giardia or whipworms)
Any dog can get colitis, but certain dog breeds are more prone, including young boxers and french bulldogs who can develop a rare type of colitis called granulomatous colitis where a bowel segment becomes thickened or partially blocked due to a bacterial invasion of the intestinal wall. It results in bloody diarrhea and weight loss. Treatment usually consists of antibiotic therapy and dietary changes as well as corticosteroids.
Treatment for Colitis in Dogs
A trip to the vet is strongly advised if you see any symptoms of colitis. They might initially provide some fluids under your dog’s skin to help with hydration. Then, depending on their findings, antibiotics may be prescribed which also have some anti-inflammatory properties. Courses of these are often tried in the beginning to help resolve colitis, and if it does not improve, your vet may suggest your dog undergo a diet trial for further diagnostics.
If the colitis has been brought on by stress, then it’s important to do what you can to reduce your dog’s stress and anxiety levels. This won’t necessarily stop the diarrhea, but it can prevent it from getting worse or recurring. Of course, a trip to the vet may add to your dog’s stress level, but it’s usually necessary before beginning treatment.
Vets typically recommend a period of fasting for one to two days in order to rest the GI tract. Your dog may also be prescribed a novel-protein diet or a hydrolysed-protein diet in the case of food allergies. Otherwise a high-fibre diet may help in certain cases of colitis (often alongside medication).
Colitis can be managed with diet changes. A bland diet consists of a simple protein, like boiled chicken (no skin, no spices), cooked mince, or fully cooked eggs, as well as a simple carbohydrate, like brown rice or sweet potatoes.
Supplementing the diet with fibre often improves diarrhea in most animals. It reduces water in their faeces, prolongs transit time (allowing more water to absorb), increases the faecal bulk, and improves the intestine’s ability to contract. You can add fibre through a prescription fibre diet, canned pumpkin or psyllium husks.
Prebiotics and Probiotics
Prebiotics act as food for the beneficial bacteria in the colon. They help maintain a healthy bacterial population there, which, in turn, helps resolves the diarrhea. Probiotics are a protected culture of live bacteria that can help colonise the gastrointestinal system and promote beneficial bacterial balance. These will also help relieve the diarrhea.
Dewormers are used to treat parasitic infections causing colitis in dogs. The exact type of dewormer will depend on the type of parasite.
Dogs with severe colitis can need to be hospitalised for supportive care, as intravenous fluids are needed to rehydrate and balance electrolytes. During hospitalisation, dogs may also be treated with anti-diarrhea drugs to provide relief.
Recovery and Management of Colitis in Dogs
Most cases of acute colitis clear up fairly quickly with basic treatment. But dogs with chronic colitis (especially those with inflammatory bowel disease) may experience flare-ups throughout their lives. Depending on the underlying cause, chronic colitis may not be curable, but it can be managed and controlled through one or more of the following: diet, fibre supplements, antibiotics, and corticosteroids/anti-inflammatories/immune modulators. These dogs may need to remain on a special vet-recommended diet, with the addition of medication.
If diet and medications do not help, it may be time for advanced diagnostic testing. Your vet may recommend a colonoscopy and/or MRI to check for more serious issues. This may include a referral to a veterinary internal medicine specialist.
Warning: Do not give your dog any human medications at home. Dogs do not metabolise medications the same as we humans, so giving your dog a human medication is dangerous. It can also be counterproductive without knowing the exact cause of the colitis.