Episodes of acute diarrhoea in dogs and cats are frequently encountered in small animal practice. Many episodes will improve with symptomatic care, but antibiotics are often included in the initial treatment strategy. We will explore common causes of acute diarrhoea and discuss the role of faecal analysis. Question is, does it ever really change what we do?! We will explore when and why antibiotics are prescribed in the management of acute diarrhoea, whether they are always indicated in these situations and the potential adverse effects that antibiotic use may cause. From probiotics to faecal microbiota transplant… we will consider what we know and what really works.