Diabetes Mellitus in Cats
Diabetes in cats is most similar to type 2 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.
Obese, middle-aged indoor male cats are most likely to develop diabetes, but it can happen to any cat at almost any age. There is the possibility that your cat will not need life-long insulin therapy, especially if diagnosed early and the blood sugar is stabilized quickly.
What to Watch For
- Increased water consumption
- Increased urination, possibly urinating outside the litterbox
- Increased appetite (early stages) or loss of appetite (late stages)
- Weight loss
Sometimes the cat will develop a plantigrade stance – that is, he will stand and walk with his hocks touching or nearly touching the ground. This is a form of diabetic neuropathy.
If a diabetic cat goes untreated for long enough, it will develop ketoacidosis. Cats at this stage will not eat or drink, become dehydrated and more lethargic. Eventually they will slip into a coma and die if not treated immediately.
The insulin produced by the cat is either insufficient or ineffective.
It is important that you schedule an appointment with your veterinarian if you suspect you cat has diabetes. In the meantime, let him have all the water he wants.
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 the blood and urine, your vet will be checking for evidence of other disease that have symptoms similar to diabetes, like kidney disease and hyperthyroidism.
S/he will also be checking for conditions that can complicate the treatment of diabetes, like infections and ketoacidosis, which requires hospitalization.
The goals of treatment are to have a cat that is free of diabetic symptoms and that has a blood glucose level that is near normal. To achieve this, the course of treatment will have to be individualized for your cat.
If your cat has developed the complication of ketoacidosis, he will be hospitalized and given IV insulin as well as IV fluids until he is eating and his blood sugar stabilizes. Then he will be switched to subcutaneous insulin and sent home. Infections can interfere with proper glucose regulation, so if your cat has any infections, they will need to be treated first.
At-home insulin therapy commences once the diagnosis has been confirmed and any infection or ketoacidosis is under control. Your veterinarian will give you instructions and demonstrate how to give your cat insulin at home. The most commonly used insulins in cats are glargine and PZI. The insulin is given by injection under the skin, usually twice a day.
If you think your cat may have received an overdose of insulin, give it corn syrup by mouth. If he is unable to swallow, rub the syrup on the gums.
After your cat has been on insulin for about a week, a glucose curve is done. This is a series of timed blood glucose measurements taken over the course of a day. 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.
Treatment also involves switching your cat to a high protein, low carbohydrate canned food, if possible, and weight loss if your cat is obese.
Feeding your cat too much “people” food can cause inflammation of the pancreas, the location of insulin-producing cells, which can inhibit insulin production. Prolonged use of corticosteroids can also predispose the cat to diabetes.
Living and Management
Having a cat with a chronic illness like diabetes requires your full commitment. S/he will require twice daily insulin injections, most likely for life, as well as regular blood tests.
You should learn how to take blood glucose readings at home. This involves pricking the ear for a drop of blood, much like a human diabetic pricks his finger. This will not only save you time and money, it will actually get better results. The stress of a trip to the vet can actually cause an artificial elevation in the blood glucose. You can even do the blood glucose curve at home with some coaching from your veterinarian.
You also need to be observant for changes in your cat’s response to insulin. If the original symptoms start reappearing, 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 his feet a few hours after his insulin was given, or you find him unconscious or seizing, this is likely a sign of insulin overdose or it could indicate that his dependency on insulin is lessening.
If you find your cat showing any of these signs, give him corn syrup by mouth (any kind of syrup can be used if corn syrup is not available). The syrup will not hurt him no matter how much he gets (unless he inhales it). You should contact your veterinarian, or take your cat to her, depending on the severity of the symptoms.
Diabetes cannot be prevented, per se, but the risk for 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 corticosteroids if possible.
If your cat does get diabetes, then the goal is to prevent complications from developing. The most important step is good communication. Talk to your vet about any changes you observe in your cat. Ask questions about anything you do not understand; there is a lot more to know about caring for a diabetic cat than is described here.
Communication between family members is also important. Who will give the cat insulin and when? What does the cat eat and when? How many and what kind of treats? What the symptoms are for insulin overdose and what should be done, etc.