Reviewed and updated for accuracy on August 9, 2019 by Dr. Hanie Elfenbein, DVM, PhD
Diabetes in cats is most similar to type II diabetes in people: the blood sugar becomes elevated because the cat’s insulin is either ineffective or not produced in sufficient quantity. If not treated accordingly, it can become a life-threatening condition.
Indoor, middle-aged, obese cats are most likely to develop diabetes, but it can happen to any cat at almost any age.
With the successful introduction of a weight loss plan, it’s possible that your cat will NOT need lifelong insulin therapy, especially if diagnosed early and the blood sugar is stabilized quickly.
Feline Diabetes Symptoms to Watch For
Weight loss, even though your cat has a good appetite
Increased water consumption (most common symptom)
Increased urination, possibly urinating outside the litter box
Increased appetite (early stages) or loss of appetite (late stages)
Sometimes a cat will develop a plantigrade stance—that is, he will stand and walk with his hocks touching or nearly touching the ground. Instead of walking only on his paws, it would look like his whole foot is touching the ground. This is a form of diabetic neuropathy.
If a diabetic cat goes untreated for long enough, they will develop ketoacidosis. Cats at this stage will not eat or drink and will become dehydrated and more lethargic. Eventually, as ketoacidosis progresses, they will slip into a coma and die if not treated with intensive medical therapy.
Primary Cause of Diabetes in Cats
The primary cause of diabetes in cats is that the insulin that their body produces is either insufficient or ineffective. This means that insulin is either not helping glucose get into the cells to supply energy or that there is not enough insulin to do its job efficiently.
There are a few different ways that cats can contract diabetes.
Feeding Human Food
Feeding your cat too much “people” food can cause inflammation of the pancreas—where you find insulin-producing cells—which can inhibit insulin production.
Prolonged Corticosteroid Use
Prolonged use of steroids can also predispose a cat to diabetes.
Being overweight puts cats at high risk for developing diabetes. Many indoor cats gain weight as they age. If your cat is overweight, ask your veterinarian what you can do to help them achieve a healthy weight and reduce their risk of diabetes.
It is important that you schedule an appointment with your veterinarian if you suspect that your cat has diabetes. In the meantime, provide plenty of water and keep an eye on the water dish or fountain, because you will have to refill it more often.
If your cat is very ill or not eating, they need immediate veterinary attention. By the time a cat with diabetes has lost their appetite, they are very sick.
Diagnosing Diabetes in Cats
After a physical exam and discussion of your cat’s symptoms, your veterinarian will take blood and urine samples for testing.
In addition to checking the glucose (sugar) levels in your cat’s blood and urine, your vet will be checking for evidence of other diseases that have symptoms similar to diabetes, like kidney disease and hyperthyroidism.
They will also check for conditions that can complicate the treatment of diabetes, like infections and diabetic ketoacidosis, which require hospitalization.
Treatment for Diabetic Cats
The goal of treatment is to have a cat that is free of diabetic symptoms with a blood glucose level that is near the normal range.
To achieve this, the course of treatment will have to be individualized to your cat. Diet change and weight loss may be prescribed in addition to insulin therapy.
If your cat has developed the complication of diabetic ketoacidosis, they will be hospitalized and given IV insulin as well as IV fluids until they are eating and their blood sugar and electrolytes stabilize. Then they will be switched to subcutaneous insulin and sent home.
Infections can interfere with proper glucose regulation, so if your cat has any infections, those will need to be treated first. Urinary tract infections are common in diabetic cats, and your veterinarian may recommend regular screening to prevent complications.
At-Home Insulin Therapy
At-home insulin therapy commences once the diagnosis has been confirmed and any infections are under control. Your veterinarian will give you instructions and show you how to give your cat insulin at home.
There are many factors that go into your veterinarian’s choice of insulin, including your specific cat’s needs and relative costs. The most commonly used insulins in cats are glargine and PZI.
The insulin is given by injection under the skin, usually twice a day, after your cat has eaten.
After your cat has been on insulin for about one to two weeks, a glucose curve is performed. This is a series of timed blood glucose measurements taken over the course of a day, most often in the hospital.
Based on your cat’s symptoms and the test results, the insulin dose is adjusted and the glucose curve is repeated. This cycle is repeated until your cat shows no diabetic symptoms and the blood glucose levels stay within an acceptable range.
This stage of treatment may take weeks to months. It is important to be patient.
Increasing insulin too quickly can result in death, so your veterinarian has to make small changes each time for your pet’s health and safety.
High-Protein, Low-Carb Diet
Treatment also involves switching your cat to a high-protein, low-carbohydrate canned food, if possible, and weight loss if your cat is obese.
These steps of treatment are just as important as insulin.
The importance of weight loss cannot be stressed enough for diabetic cats. Cats may go into diabetic remission, meaning they no longer require insulin, if they lose weight.
Be just as consistent about your cat’s weight loss plan as you are about her insulin, and you may achieve remission.
Living and Management for Diabetic Cats
Having a cat with a chronic illness like diabetes requires your full commitment. They will require twice-daily insulin injections, possibly for life, as well as regular blood tests.
Your veterinarian may recommend that you learn how to take blood glucose readings at home. This involves pricking your cat’s ear for a drop of blood, much like a person who is diabetic pricks their finger.
This will not only save you time and money, but it will enable you to monitor your cat’s blood glucose within the comfort of their home environment.
The stress that comes from a trip to the vet can actually cause an artificial elevation in the blood glucose, so if your cat has trouble with being in the car or at the vet’s office, talk to your veterinarian.
You can even do the blood glucose curve at home with some coaching from your veterinarian.
Pay Attention to Insulin Responses
You also need to watch for changes in your cat’s response to insulin.
If the original symptoms reappear, your cat may need a change in insulin dose or a trip to your veterinarian to see if other problems, like a bladder infection or hyperthyroidism, have developed.
If your cat starts acting disoriented or unsteady on their feet, or you find them unconscious or seizing, this is likely a sign of insulin overdose, causing blood sugar that is too low (hypoglycemia).
If your cat shows any of these signs, give them corn syrup by mouth (or honey or maple syrup). Use only a small amount so that your cat does not choke on it (less than 1 teaspoon).
Use your finger to rub the syrup on their gums. You should contact your veterinarian, or take your cat to them, immediately.
Life Expectancy in Cats With Diabetes
The life expectancy of cats with diabetes varies depending on the specifics of their situation. For a cat that is otherwise in good health, diabetes that is well-regulated may not shorten their life.
However, some cats are more difficult to regulate or have an interfering disease, so their prognosis may be different depending on the illness.
Prevention of Diabetes in Cats
Diabetes cannot be prevented, per se, but the risk for cats getting diabetes can be reduced.
Do not allow your cat to become obese—encourage exercise, feed cat-appropriate food and avoid long-term use of steroids if possible.
If your cat does get diabetes, then the goal is to prevent complications from developing while also trying to reverse your cat’s insulin dependence through diet and exercise.
Communication Is Essential for Treating Feline Diabetes
The most important step is maintaining good communication with your veterinarian. Talk to your vet about any changes you observe in your cat. Ask questions about anything you do not understand; there’s a lot more to properly caring for a diabetic cat than is described here.
Communication between family members is also important. Who will give the cat insulin and when? How will you record when your cat has received insulin? What does your cat eat and when? How many and what kind of treats? What are the symptoms of an insulin overdose, and what should family members do to help?
Taking care of a diabetic cat is a lot of work and needs to be taken seriously. Once their blood glucose is managed, they can go on being a happy cat, and that is the most important thing.
Featured Image: iStock.com/themacx