Dr. Wise answers two questions regarding diabetes in cats.

Carey, our six year-old cat, is diabetic.  We are having a problem keeping her stabilized and find that she still drinks and urinates too much.  Can you give us any help?

Diabetes, relatively common in cats, requires insulin injections to help keep it under control. It is important to be very observant with a diabetic cat because some of them can be very difficult to regulate. As you note, drinking and urinating indicate how well the problems is controlled. When Carey is doing better, both should return to near normal.

At this point, I recommend hospitalization so glucose levels in Carey’s bloodstream can be checked every two to three hours for a 12-24 period. She will receive an insulin dose in the morning and have blood samples taken through the day. Over the 12-24 hours, this will show what is called a glucose curve that indicates if the insulin dose needs to be changed. It will also show if Carey is using her insulin too fast and needs injections every 12 hours. About 75% of diabetic cats need injections every morning and night.

The testing will indicate if Carey is resistant to the insulin. This can happen if there is a bacterial infection such as a bladder infection.  Diabetic cats need to be watched because they are prone to infections since bacteria can grow more easily in their bodies when glucose levels are elevated.   Resistance to insulin can also be caused by pregnancy, hyperthyroidism, and other less common hormone problems.

Diet is an important part of diabetes control. Carey needs a high quality food which has an adequate amount of fiber which allows her to use insulin more evenly throughout the day. Avoid semi-moist food (in the plastic pouches) because they are metabolized too quickly. Your veterinarian can recommend specific foods.

Carey should do much better if you follow these steps. Prepare yourself to be patient. Determining the right amount of insulin can require repeated testing and retesting.

My roommate's cat has been diagnosed with diabetes.  I'll be taking care of him sometimes when my roommate is gone.  What is diabetes and what will I need to watch for?

Diabetes mellitus is a disease that results when the pancreas produces no insulin or an insufficient amount to regulate the body's blood sugar or blood glucose.  Insulin is the hormone that keeps the blood glucose above normal levels.   Too much insulin will reduce glucose below normal, and not enough insulin (or none at all) will elevate glucose above normal levels.  Your roommate's cat is not producing enough insulin and, therefore will likely need insulin injections. 

High blood glucose levels do not mean that an animal definitely has diabetes, but when levels are too high for too long, the kidney's start "spilling" glucose into the urine.  Thus, high blood glucose values and glucose in the urine need to be present to definitively diagnose diabetes. 

Clinical signs of diabetes include drinking excessive amounts of water, urinating excessively, eating more than usual, and weight loss.  Some or all of these signs are either seen before diabetes is diagnosed or when the diabetes is not controlled well enough with insulin.   If the cat is getting insulin injections, the injections need to be given at certain times of the day, usually twice but sometimes once daily.  You need to make sure the cat is eating before you give the insulin.   Insulin makes the blood glucose go down and if the cat is not eating, his glucose could get too low and cause him to go into a coma.  You also need to monitor his water intake and urine production.  If he is not getting enough insulin, he will drink more water and produce more urine.  NEVER change his insulin dose without first checking with the veterinarian, and never limit the amount of available water or he could become dehydrated.

In a few cases in cat diabetes, the disease can be controlled with an oral pill that helps keep the blood glucose down, but most cases require insulin injections.  There are special syringes with tiny needles that are used for insulin injections.  It usually is not too hard to learn how to give injections, and most cats tolerate them well. 

In many cases, cats with diabetes should receive a special type of food that helps regulate blood glucose.  This means that you should only feed the food prescribed by the veterinarian.  Dogs can get diabetes too and also require insulin injections and special food.

This information, prepared as a public service by the Rhode Island Veterinary Medical Association, answers problems Rhode Island veterinarians currently are seeing in their practices, as well as new developments in animal care.