The easy way to a correct diagnosis: comprehensive and conciseExpert knowledge for everyday clinical workHelpful tool for studies and exams! How to achieve a reliable diagnosis – even in complex clinical cases! Internal medicine cases can be complex and challenging. To manage such challenges, it is helpful to know the possible pathophysiological causes of a particular clinical problem, to be able to evaluate this problem in an individual case and to exclude anything not relevant for this patient using diagnostic pathways. This book describes this process of exclusion (“ruling out”) for all aspects of internal medicine in dogs and cats, and ultimately leads to confirmation of a specific diagnosis. Rule outs therefore are an important basis for everyday clinical work and provide a practical guideline for a systematic problem-oriented approach to patients. For students, these rule outs are a prerequisite for understanding the pathophysiology of clinical presentations and laboratory changes. For experienced clinicians, rule outs are a helpful diagnostic guide especially when dealing with complex cases.