Evolutionary developments in the diagnosis of chronic kidney disease (CKD) have helped our understanding of CKD pathophysiology evolve as well. This evolution has created a paradigm shift as traditional diagnosis—occurring when cats and dogs became clinically ill—can now occur prior to any clinical signs, leading to a new wave of clinical research into early diagnosis, treatment, and prevention of CKD. We will cover updates on CKD pathophysiology; risk factors; diagnosis; and treatments, including diets.