Feline inflammatory bowel disease (IBD) is one of the most common causes of chronic vomiting and diarrhoea in cats, causing significant ongoing welfare compromise that requires systematic long-term management.
Feline IBD encompasses several forms depending on the predominant inflammatory cell type: lymphocytic-plasmacytic enteritis (most common); eosinophilic enteritis; and granulomatous disease (rare). The distinction between IBD and low-grade alimentary lymphoma (LGAL) can be challenging and requires histopathology—these conditions may represent a continuum. Chronic vomiting, diarrhoea, weight loss, reduced appetite, and intermittent haematochezia reflect gastrointestinal inflammation causing ongoing discomfort.
Diagnosis requires ruling out other causes of chronic vomiting and diarrhoea (hyperthyroidism, CKD, food intolerance, infectious causes) through bloodwork, urinalysis, ultrasound, and dietary trials. Definitive diagnosis requires biopsy—endoscopic or surgical—for histopathology. Cobalamin (B12) deficiency from malabsorption requires measurement and replacement. Folate levels reflect jejunal function. Ultrasound provides non-invasive assessment of intestinal wall thickening and lymph node changes.
Hydrolysed protein diets or novel protein diets reduce antigenic stimulation of intestinal immune cells in many IBD cats. A 4-8 week dietary trial with strict compliance (no other food sources) demonstrates whether food sensitivity contributes to disease. Many cats show meaningful improvement on appropriate elimination diets. Long-term dietary management with single-protein or hydrolysed diets maintains remission in food-responsive cases.
Prednisolone is the primary immunosuppressive treatment for IBD, reducing intestinal inflammation and improving clinical signs. Chlorambucil is added in prednisolone-resistant or intolerant cases and is standard therapy for LGAL. Metronidazole has anti-inflammatory and antibiotic properties supporting IBD management. Long-term monitoring (3-6 monthly bloodwork, cobalamin levels, body weight) adjusts treatment as disease evolves. Cobalamin supplementation is important in deficient cats—it supports intestinal cell function and immune competence.