The value of GI biopsies in cats: Chronic diarrhoea in cats can be a thoroughly frustrating affliction for patients, owners and vets alike. What are the common underlying aetiologies? Do these change according to the age of the cat? Or the breed? Which extra-digestive causes should be considered? Can faecal analysis ever be useful? How can you get the most out of such samples? Does abdominal imaging provide any helpful clues? If you’re going to collect gastrointestinal biopsies, does it matter which parts of the gastrointestinal tract you sample? Is endoscopy as good as surgical biopsy? Do therapeutic trials have a role to play in the diagnostic algorithm? This lecture delves into some of the common (and not so common) causes of chronic diarrhoea in cats and try to answer at least a few of the questions listed above.