Inflammatory Bowel Disease (IBD)

Inflammatory bowel disease in dogs refers to a group of chronic gastrointestinal conditions characterised by persistent infiltration of the bowel wall with inflammatory cells. It is not a single disease but a pattern of chronic GI inflammation with several subtypes depending on which cell type predominates and which section of the GI tract is most affected.

IBD can affect the stomach, small intestine, large intestine, or combinations. Signs vary accordingly:

• Small intestinal IBD: Large-volume, watery or greasy stools; weight loss; vomiting
• Large intestinal IBD (colitis-dominant): Frequent, small-volume, often mucousy or bloody stools; urgency; less weight loss
• Gastric IBD: Vomiting, particularly of bile or undigested food

What to monitor daily

For a dog with diagnosed IBD, log:

Stool quality. Score using the Bristol Stool Scale or a simpler 1–5 system (1 = very hard; 3 = ideal; 5 = liquid diarrhoea). Note frequency, volume, presence of blood or mucus.

Vomiting. Time, frequency, character (food, bile, undigested, partially digested). Note whether vomiting follows meals, is random, or correlates with specific foods.

Appetite. Full, partial, or absent. Note any food preferences or aversions.

Weight. Weigh weekly - weight loss is a key indicator of disease severity and treatment response.

Energy and demeanour. Active and engaged vs. quiet and withdrawn.

Abdominal comfort. Signs of pain: hunching, reluctance to be touched on the abdomen, borborygmi (audible gut sounds).

Stools during dietary changes. IBD is often managed with dietary modification - log stools carefully during any food transition to separate response to the new diet from baseline disease.

Diagnosis

IBD is a diagnosis of exclusion and histological confirmation. The diagnostic pathway typically includes:

• Blood work (complete blood count, biochemistry, cobalamin/B12 and folate levels - these are absorbed in specific GI segments and their deficiency indicates functional impairment)
• Urinalysis and faecal analysis (to rule out infection, parasites)
• Imaging (abdominal ultrasound - bowel wall thickening, lymph node changes)
• Endoscopy and biopsies - the only way to definitively classify IBD and determine the subtype

Cobalamin deficiency is common in dogs with small intestinal IBD and causes neurological signs, immune dysfunction, and worsens GI function. Supplementation is often required.

Treatment

Dietary management:

• Hydrolysed or novel protein diets reduce the antigenic stimulus in dogs with food-responsive IBD (which accounts for a significant proportion of cases)
• Many dogs improve on a strict dietary trial before requiring immunosuppressant medication

Immunosuppressant therapy (for dogs not adequately controlled by diet):

• Prednisolone - the most commonly used first-line drug
• Budesonide - a locally-acting steroid with fewer systemic side effects, particularly useful for intestinal-dominant disease
• Azathioprine or ciclosporin - for refractory cases or as steroid-sparing agents

Cobalamin supplementation - weekly injections or daily oral supplements if deficiency is identified.

Probiotics and prebiotics - modest evidence but low risk; may support gut microbiome health.

Monitoring treatment

Log response to any treatment or diet change for at least four weeks before assessing effectiveness. IBD often shows partial responses that can mislead - a log showing stool quality improved from 4/5 to 3/5 but not to 2/5 helps distinguish partial response from no response.

When to contact your vet

Contact your vet soon if:

• Vomiting or diarrhoea is frequent and the dog is losing weight
• Signs have been present for more than two weeks without clear cause

Contact your vet promptly if:

• Blood in stools is significant or increasing
• The dog is not eating and has lost visible body condition
• Current treatment is not maintaining adequate control

Frequently Asked Questions

How is IBD different from a sensitive stomach? Occasional loose stools or vomiting after dietary indiscretion is common and not IBD. IBD involves persistent or recurring GI signs - typically present for more than 3–4 weeks, often with weight loss, and without resolution on standard dietary management. The diagnosis requires ruling out other causes.

Can IBD be cured? For dogs with food-responsive IBD, a strict dietary change can achieve complete remission. For dogs requiring immunosuppression, the condition is managed rather than cured - medication may be reduced as the dog stabilises, but completely stopping treatment frequently leads to relapse.

My dog has IBD - does that mean they'll be on medication forever? Not necessarily. Some dogs achieve long-term remission on dietary management alone. Others require long-term medication. The approach is to find the minimum effective treatment - often a combination of diet and medication that keeps the dog comfortable with minimal side effects.

Should I be giving probiotics to my IBD dog? Some evidence supports probiotic use in dogs with GI inflammation. While the evidence base isn't as strong as for some other treatments, well-formulated veterinary probiotics are low-risk and may provide modest benefit. Discuss specific products with your vet.

My dog was diagnosed with IBD but I'm not sure we've found the right diet. What should I try? For food-responsive IBD, a strict hydrolysed or novel protein elimination diet followed for 6–8 weeks is the most reliable approach. Over-the-counter "sensitive" foods often still contain common protein sources and may not represent a true dietary trial. Your vet can prescribe a hydrolysed diet and help you interpret the response.