Diabetes Mellitus in Animals: Diagnosis and Treatment of Diabetes Mellitus in Dogs and Cats

This chapter describes the pathogenesis, clinical signs, diagnosis, and treatment of diabetes mellitus in dogs and cats. Dogs are susceptible to type 1 diabetes mellitus, insulin-dependent diabetes mellitus, or absolute insulin deficiency. It is commonly thought that cats develop type 2 diabetes mellitus characterized by obesity, insulin resistance, and pancreatic amyloid deposition. Dogs present with polydipsia, polyuria, and cataract formation; however, the diagnosis of early type 2 diabetes in cats can be challenging. Diagnosis in dogs is made on the basis of fasting hyperglycemia and glucosuria; however, cats are susceptible to stress hyperglycemia and have a higher renal threshold for glucose, therefore glycated blood proteins are often used to diagnose diabetes in cats. Dogs require insulin therapy to prevent development of ketoacidosis. Cats, however, can often be managed with diet and insulin, diet and oral hypoglycemic therapy, or diet alone.