Feline diabetes

Many times during my thirteen years as an emergency veterinary technician calls would come in from cat owners who would tell us their cat “just didn’t seem right.” Upon further questioning they would relate how their cat was drinking and urinating more. The owners would also tell how the cat had lost weight even though its appetite was good. When we would hear this grouping of symptoms, one of the most common, although complex of feline endocrine disorders would be suspected. This disorder is diabetes mellitus.

Diabetes mellitus is often called “sugar diabetes” and it comes in two types.

Type 2 diabetes is a result of an inadequate response by the cat to insulin.

High blood sugar levels (hyperglycemia) develop because the animal’s (and humans) body is unable to break down and use glucose properly. This inability causes sugar to appear in the urine (glucosuria) that in turn causes an excessive amount of urination (polyuria). To compensate for the increase in urination the cat must drink an excessive amount (polydipsia). Another common side effect of feline diabetes mellitus is weight loss in a cat that has maintained a good or even increased appetite.

Although excessive drinking and urination are the most common symptoms, they are in no way the only ones. In addition to the weight loss, cats can also develop signs of poor skin and hair coat, liver disease, vomiting, weakness in the rear legs (diabetic neuropathy), secondary bacterial infections and dehydration. They can also develop a life threatening condition known as ketoacidosis. A cat whose diabetes is not regulated may become blind or have kidney problems develop as well.

The cause isn’t known but medical experts feel heredity, obesity and the taking of certain medications increase the chances of a cat developing diabetes. Diabetes mellitus can affect any age, breed or sex of cat although it occurs most often in obese males.

A veterinarian will first do a physical exam, then run a number of blood and urine tests to diagnosis diabetes. The urine will be checked for specific gravity, which tells its concentration. Urine will also be checked for glucose (sugar), the presence of blood, ketones, creatinine levels and several other liver/kidney functions. The blood will also be tested for exact glucose and BUN levels as well as several liver, kidney and heart enzymes.

The normal blood glucose level in cats is between 60 and 120. If an abnormally high glucose level is found, the cat is usually kept for several days while the levels are monitored every one to three hours. If the glucose levels continue to remain elevated the veterinarian will discuss treatment options with the owner. It will be ultimately up to the owner as to whether the cat is euthanized or placed on a special diet while also given medications such as an injectable form of insulin or the oral medication Glipizide. The most common and affective treatment available is giving insulin but many owners feel they are not up to the task of giving one or more injections daily as well as checking blood glucose levels on a regular basis.

If the owner decides to begin treatment, the cat will still be kept several more days in the animal hospital. If the pet is dehydrated or suffering from ketoacidosis, he or she will have an IV catheter placed through which fluids are given. All cats will be given insulin injections once or twice a day. Blood glucose levels will usually be checked first thing in the morning before medicating and eating, an hour after the insulin is given and then several times during the day. The time in between blood tests will vary according to the wishes of the individual veterinarian. After working in a practice with nine different veterinarians, I can assure you each one will have his or her own opinions as to when the best times will be.

Another reason for differences in time and medications is that each cat responds differently to insulin. There is more than one type of insulin choice and finding the correct dosage is the tricky part. A dosage that is too low will not control the diabetes whereas a dosage that is too high can cause too low of a blood sugar level (hypoglycemia).

Hypoglycemia can be a life threatening complication to treatment of diabetes mellitus. Signs can include but not restricted to weakness, lack of co-ordination, seizures, coma and even death. If hypoglycemia occurs and the cat is conscious, a mixture of kayro syrup or sugar and water may be given orally. The cat will also be offered its normal diet.

In the case of a cat that is comatose or seizuring, an IV fluid mixture of water and dextrose will often be given. Food or oral liquids should never be given to these animals. For one thing you will not want to get your hands or fingers around the mouth of a seizuring cat because of the risk of bites. For another, an unconscious or seizuring animal can aspirate the fluids and set up a secondary condition known as aspirate pneumonia.

Once the cat has been regulated on its insulin or Glipizide, it will be sent home with special feeding instructions. These instructions will often include the reduction in diet to allow the cat to lose weight. Obesity is often a contributing factor in diabetes mellitus and by losing weight; the cat may even be able to come off the medication at some time.

Weight loss in cats must be carefully monitored and done over a long period of time. Hills/Science Diet, Purina and Iams/Eukanuba each have diets that are beneficial to the control of the diabetes as well as weight loss. These diets are usually high in fiber and carbohydrates. Your veterinarian will give you specific instructions on the type of food, amount be given and what times of the day you should give it. Normally the food will be broken up into at least two feedings. The morning one will be given with the insulin dose and the second one will be given during the peak blood glucose times as determined by the monitoring that would have been done in the hospital or, if two insulin injections are given a day, the second feeding will be given then.

In addition to instructions about feeding, your veterinarian should educate you in the storage (usually refrigerated), use and administration of the insulin. Most will also have handouts about diabetes in general, diet and signs of hypoglycemia as well as advice about the best glucometer to buy, its use and how to acquire blood samples. He or she will also want to set up follow up visits to monitor progress in the control, weight loss and general health of the cat.

Proper care and monitoring of the diabetic cat will require an excellent level of communication between you the owner and the veterinarian treating the cat. If you feel uncomfortable dealing with the veterinarian or have difficulty getting a return call, you would do best to look for a different doctor. You will also want to find out how your doctor handles emergencies. Will he or she take the calls or will they be referred to a local emergency clinic. If referrals are the norm, be sure to know the number and how to get to the clinic if needed.

The initial cost of hospitalization and regulation isn’t cheap. In fact it can run up into the hundreds of dollars but once regulated, most cats suffering from diabetes mellitus can live long, happy lives as long as the owner is willing to make the needed effort to control and monitor the blood glucose levels.