Diabetes in humans has reached epidemic proportions.  Statistics from the Centers of Disease Control show that in 2007, nearly 24 million Americans had diabetes.  Statistics are no less alarming when it comes to cats.  Just as for humans, there has been a tremendous increase in diabetes in cats over the past decade.   Diabetes affects as many as 1 in 50 cats, with overweight cats being especially prone to the disease.

What is diabetes?

Diabetes results from inadequate production of insulin by the pancreas or an inadequate response of the cells to insulin.  Without insulin, the body can’t utilize glucose.  This results in elevated blood sugar levels (hyperglycemia).  In diabetic cats, excess glucose is eliminated by the kidneys,  producing frequent urination.  This in turn leads to increased water consumption to compensate for the increased urination.

There are three types of diabetes in cats:

Type I:  Cats are insulin dependent and need to receive daily insulin injections because the beta cells of their pancreases are not making enough insulin.

Type II:  The pancreas may make enough insulin but the body cannot utilize it properly.  This is the most common type of feline diabetes.  Some of these cats will require insulin as well, but others may get by on dietary changes and oral drugs to control blood glucose.

Type III:  This is known as transient diabetes. These are type II cats who present as diabetics and require insulin initially, but over time, their system re-regulates so they can go off insulin.


While diabetes can affect any cat, it mostly presents in older, or overweight cats.  The four classic signs noticed by most cat owners are an increased, almost ravenous appetite, weight loss, increased urination, and increased water consumption.


Diabetes is diagnosed with a thorough physical exam and laboratory testing of blood and urine.  If the cat’s glucose is elevated, a second blood test, called a fructosamine, will provide more information.  This test measures the average level of glucose control over the past few weeks.


Diabetes is treated with a combination of diet, insulin, or oral glucose medications.

What causes diabetes in cats?

While diabetes can affect any cat, it occurs more frequently in middle-aged and older, obese cats.  It is more common in male cats.  The exact cause of the disease in cats is not known,  but obesity and poor diet seem to be major factors.  Other causes may include chronic pancreatitis, other hormonal diseases such as hyperthyroidism, and certain medications such as steroids.

The link between diet and diabetes

More and more evidence shows that diabetes in the cat is a preventable disease, and is most likely caused by the high carbohydrate content of most commercial pet foods, especially dry foods.  Since so many cats eat primarily dry food, these poor-quality, highly processed, carbohydrate rich diets that are the equivalent of sugared breakfast cereals are increasingly thought to be the major culprit for the epidemic increase in diabetes in cats.

A diet high in meat-based protein and free of grains and carbohydrates, either raw or canned, is not only the ideal diet for cats to prevent diabetes in the first place, but should also be the diet of choice for a diabetic cat.  Veterinarians vary in their approach when it comes to diets for diabetic cats.  Many traditional veterinarians still use high-fiber diets for these cats, but more and more holistic vets as well as feline vets have turned away from this approach.  Dr. Elizabeth Hodgkins makes a convincing case for how a grain-free diet can help diabetic cats and reduce, or even eliminate, the need for insulin.  Her website Your Diabetic Cat provides a wealth of information on the connection between diet and diabetes.

There is no cure for diabetes.  However, with proper dietary management, some cats may no longer need insulin.  If diabetes has resulted from consumption of a poor quality diet and/or obesity, it is likely to improve or even completely resolve once the cat’s weight is under control.

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14 Comments on Diabetes in Cats: Treatment and Prevention

  1. Hello Ingrid, I am an avid reader of your blog. Yesterday my beloved cat Oskar, got diagnosed with diabetes. He is not overweight, he is 9.3 pounds and I have been feeding him healthy canned food. So his diagnosis is surprising. The vet prescribed what seems to me a bad brand of food: purina DM. I was wondering is you have suggestions of good quality canned food high on protein low on carbohydrates. Any advise will be very welcome. Thank you.

  2. The book Sugar Babies really helped me with my diabetic cats. It’s a horrible thing injecting daily. Did it, but broke my heart.

  3. There’s a woman I’ve run into at at least three cat-related events around town. She had one diabetic cat and another that was recently diagnosed. She knows the dry food story but apparently she’s feeding what her vet is recommending … dry food. I gave her my card, told her about Dr. Hodgkins, but she doesn’t get it.

  4. Gracey, I’m sorry you’re dealing with this – here’s wishing you another quick recovery from your diabetes. It’s a balancing act with the food allergies, I’m sure.

  5. Thank you for this informative post, Ingrid. I had transient diabetes two years ago and was fortunate to recover. Unfortunately, my diabetes returned one month ago.
    i also have food allergies so we are working hard to keep me healthy.

  6. Wow, that’s a lot of weight for Merlin to have gained in one month, Layla! You might want to try the freeze dried chicken or salmon treats for him. No grain, pure protein, and if Allegra’s reaction is any indication, cats will go nuts for them.

    Marg, I hope your cat will eat the grain-free food. It’s so much better for them.

    Bernadette, let’s not try and break that streak, shall we? I think the fact that you haven’t had a diabetic cat probably has a lot to do with what you’re feeding your cats.

  7. That is good information. I have a cat that probably is a prime one for diabetes. I am going to try to get him to eat he grain free canned food. If he won’t eat it, at least he will lose weight. Thanks for doing this post.

  8. My mobile vet was just over and we were talking about diet and disease and specifically how bad cornmeal is. Given our epidemic of diabetes in humans in this country, I’m not surprised about cats. Obesity isn’t good in any species. Merlin gained a pound since his last checkup so it’s time to scale back on treats.

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