Diabetes in Cats

Karen Thomas, DMV

Nowadays, most people know someone who is diabetic. Nevertheless, they are often surprised to learn their cat may be diabetic.

There are two types of diabetes seen in humans. With type 1 diabetes, the affected individual loses the ability to produce insulin. This type could occur in a cat with severe chronic pancreatitis. With type 2 diabetes, insulin is being produced but is ineffective. This is the more common type seen in cats and occurs most often in obese, middle-aged cats. Either type may also occur in cats that are not overweight and/ or younger. The signs usually noticed by the owners are excessive thirst and appetite which can lead to accidents in the house or an overflowing litter box. Diabetic animals lose weight despite eating ravenously.

Without insulin, or in cases where the cat is insulin-resistant, sugar builds up in the blood stream while cells starve. The cat eats more because the cells are starving. At the same time, the body tries to wash out the excess sugar by causing excessive thirst and urination. Diabetes causes other, less obvious problems. Infections are more common and less obvious because of the immune system effects of diabetes. Wounds may be slower to heal.

A simple urine dip stick test can be used to diagnose diabetes but blood tests, including a Feline Pancreatic Lipase Immunoreactivity (FPLI) test, may be indicated to check for other conditions and rule out chronic pancreatitis as the cause. A urine culture is also wise as the sugar in the urine encourages infection while the diabetes may hide the symptoms.

Feline diabetics may sometimes be treated with oral anti-diabetic medication, may be only intermittently insulin dependent, or may need insulin daily. Insulin will be needed in cats with type 1 diabetes associated with pancreatic disease. Occasionally, cats that have been on insulin for quite some time may suddenly begin producing their own insulin again or produce enough to overcome resistance. This is especially true if there is enough weight loss in a type 2 diabetic.

The first treatment step for a newly diagnosed but generally healthy diabetic cat would be a diet change. There are two approaches to this. High fiber diets slow the transit time of food through the GI tract, thus equalizing blood sugar levels throughout the day. Low carbohydrate foods mean less sugar to be processed by the body. Hills Science Diet prescription cat food M/D, Purina Proplan DM diet and Royal Canin Glycobalance foods are all made specifically for diabetic cats. It’s a good idea to transition to a new food while treating other complicating factors such as urinary tract infections. Also, medications such as Megesterol (ovaban) and steroids, especially depomedrol, can contribute to diabetes. These drugs should be discontinued if at all possible.

Then, oral medications may be started to attempt sugar control. The drug Glipizide, although not FDA approved for animal use, has been used for years. Other choices are Glimiperide and Acarbose. These are most likely to be effective in obese cats with type 2 diabetes. Apparently, the human drug Metformin is contra- indicated in cats. I have not seen any information on the use of other human products such as Invokana or Victoza.

If oral medications are ineffective in controlling the condition, insulin will be necessary. There are several different kinds of insulin, including one made specifically for pets. The time of peak action after injection varies with insulin type, dose, and the individual patient. Vetsulin, the veterinary product, is especially useful in diabetic cats as it is less concentrated and therefore easier to measure in the small doses needed for cats. In animal diabetics, the initial dose of insulin is estimated and then it is adjusted based on the animal’s response to therapy. This may be as simple as noting improvement in symptoms or may include daily at-home blood or urine sugar monitoring, in-clinic glucose curves, or A1C monitoring. Great care must be taken to avoid insulin overdose as this can lead to irreversible diabetic coma or a rebound high sugar following an excessive drop.

Treatment may be started in the hospital or at home. If the pet is not overtly sick at the time of diagnosis, it is usually better to begin injections in the home. Insulin may be given once or twice a day or even, rarely, three times daily. Sometimes the appropriate dose and schedule can be determined within a few days or weeks. In other cases, it can take months of trial and error with different kinds of insulin and schedules and repeated lab tests. One of the most important points in diabetes control is consistency. It is vital to stick to a schedule—giving the insulin at the same time or times each day, feeding the same amount at the same time or times and giving about the same amount of exercise daily. This helps to keep blood sugar levels consistent.

Any concurrent diseases, infections, stress or hormone swings can affect blood sugar levels and must be treated quickly and effectively. Intact females should be spayed as soon as they are stabilized. In humans, strict sugar control is important since the patient can expect to live for decades. Veterinary diabetics have a little more leeway since most will have no more than ten years left of their life expectancy at time of diagnosis. If your veterinarian diagnoses diabetes in your cat, you should think seriously about whether you will be able to provide the consistency of care needed and whether you are able to commit time and resources to its treatment. Good communication between veterinarian and owner is essential.

 

Originally published in Cat Talk Magazine