Glomerular disease is a common and often severe form of kidney disease in dogs. In contrast, it appears to be a relatively uncommon cause of kidney disease in cats. It is often a challenging condition to manage, in part because of limited understanding of the causes of glomerular disease and limited clinical studies on which to develop an evidence based approach to management. This chapter addresses the diagnostic approach to glomerular disease; standard therapy of glomerular disease; therapeutic approach beyond standard therapy; and criteria for assessing effectiveness of treatment and re-evaluation of the treatment plan.