Types Of Diabetes Mellitus In Dogs And Cats

In dogs and cats, diabetes mellitus is subdivided into three different types– I, II and III. 

Type I diabetes occurs most commonly in dogs.  The islet cells in these animals are destroyed and cannot produce insulin.  Treatment to control blood glucose levels in these patients require insulin injections just as do people with insulin-dependent diabetes mellitus. 

Type II diabetes is more common in cats and is similar to non-insulin dependent diabetes in humans.  Patients with this condition suffer from insulin resistance as well as problems secreting insulin.  Obesity is thought to be a trigger for this type of diabetes.  Although it is possible to control some cats with diet and oral hypoglycemics, others require insulin injections.

Type III diabetes is characterized by something within the patient that interferes with insulin and leads to glucose intolerance.  In my experience, Cushings’ Disease (Hyperadrenocorticism) is the most common cause of type III diabetes.  It may also occur secondary to glucocorticoid (prednisolone or prednisone) therapy.  Sometimes, this type of diabetes will often resolve after the drug is withdrawn or the Cushings’ disease is treated. 

Published by kristennelsondvm

Dr. Kristen Nelson grew up on a farm in Watertown, Minn., where she developed a deep love for animals of all kinds. She received a Doctor of Veterinary Medicine degree from the University of Minnesota, College of Veterinary Medicine. Kris then completed a small-animal internship at the prestigious Animal Medical Center in New York City. In addition to writing and speaking, she cares for small and exotic animals in Scottsdale, Az. Dr. Nelson is widely quoted in the media. Her credits include Ladies’ Home Journal, USA TODAY, the Los Angeles Times and numerous radio and television interviews. Dr. Nelson has written two books, Coated With Fur: A Vet’s Life and Coated With Fur: A Blind Cat’s Love. Kris and her husband Steve share their home with rescued cats, birds and a dog.