Lap of Love Veterinary Hospice: Does my cat have diabetes? By Dr. Charles Jameson

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The technical term for feline diabetes is diabetes mellitus, also known as “sugar” diabetes for its reference to excess glucose in the bloodstream. It is a complex, but common, disease similar to diabetes in humans, in which the cat doesn’t produce sufficient insulin or doesn’t process the insulin produced by its own body. Insulin is a hormone secreted by the pancreas in small amounts and helps to properly balance the blood sugar (glucose) levels in the blood. Glucose is the fuel that provides energy needed by the cells of the body to sustain life.

The types of diabetes in cats are based on the human classification system.

Type 1 Diabetes

Type 1 form of diabetes is defined as an absolute insulin deficiency. In this form, the pancreas is not able to produce enough insulin to regulate the glucose in the bloodstream, leading to persistent high glucose levels in the blood. This type of diabetes is very rare in the cat.

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Type 2 Diabetes

Type 2 diabetes, the most common form of diabetes in cats, occurs when the cells in the cat's body don’t respond to the insulin that is being provided. As a result, the cat becomes hyperglycemic (high blood sugar), which may lead to having excess sugar in the urine.

No test can differentiate between Type 1 or Type 2 diabetes in the cat.

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Type 3 Diabetes

Type 3 diabetes is also less common and may occur due to other conditions (e.g., secondary to another primary disease which may damage the pancreas).

While diabetes can affect any cat, older, obese and neutered male cats are more commonly associated with the disease. In addition, chronic pancreatitis, hormonal diseases and certain medications have shown a link to increased incidence of diabetes.

As in humans, diabetes is often seen in overweight cats because fat cells produce a substance that decreases the body's response to insulin (as occurs in Type 2 diabetes).

In addition, diet plays a major role in maintaining the cat's proper weight and nutrition, both of which are key determining factors in diabetic patients. Because cats are designed to consume mostly proteins and fats for energy in their diets, high carbohydrate diets may lead to weight gain and increased incidence of diabetes in many cats.

Further, diabetes is more prevalent in older cats, neutered male cats and felines with a history of pancreatic disease, hormonal imbalances and use of certain medications

Your first vet visit: diagnosing feline diabetes

Your veterinarian can diagnose diabetes with a simple, in-office physical examination of the cat and laboratory tests, which will determine if there is an abnormally high level of sugar in the bloodstream and urine.

Your veterinarian may ask if your cat has exhibited any of the following symptoms, indicating a possibility of feline diabetes:

Increased thirst
Sudden increase in appetite
Sudden weight loss (despite an increase in appetite)
Increased urination
Increased lethargy

Understanding your cat's diagnosis

The food your cat eats is broken down into glucose during the digestion process. Glucose is the fuel that provides energy needed by the cells of the body to sustain life. As glucose enters the bloodstream, the cat's pancreas secretes insulin. Insulin is a hormone released in small amounts to properly balance the blood sugar (glucose) levels in the blood.

Feline diabetes is similar to human diabetes, and occurs when your pet either doesn't produce or is unable to process insulin, a hormone that helps regulate glucose or sugar in the bloodstream.

Just like humans, diabetic cats are diagnosed primarily with Type 2 diabetes.The types of diabetes in cats are based on the human classification system.

Type 1 Diabetes

Type 2 Diabetes

Type 2 diabetes, the most common form of diabetes in cats, occurs when the cells in the cat's body don't respond to the insulin that is being provided. As a result, the cat becomes hyperglycemic (high blood sugar), which may lead to having excess sugar in the urine.

No test can differentiate between Type 1 or Type 2 diabetes in the cat.

Type 3 Diabetes

Type 3 diabetes is also less common and may occur due to other conditions (e.g., secondary to another primary disease which may damage the pancreas).

My cat has just been diagnosed with diabetes … now what?

Discovering that your pet has diabetes can seem overwhelming and scary especially since there is no cure. The good news is that feline diabetes is not a fatal diagnosis and with proper attention, your cat can live a happy and virtually normal life.

Learning how to monitor your cat's blood sugar levels will be one of the most important aspects of caring for your diabetic cat. Your veterinarian may run these tests in the hospital or may demonstrate how to test your cat's blood sugar levels at home, either through urine or blood sample testing.

Additionally, feeding your cat on a regular schedule will help prevent dips and spikes in the cat's glucose levels. Again, your veterinarian will discuss specific dietary changes and options to best fit your pet, your family and your lifestyle.

Finally, it's important to understand that you and your cat are not alone — the more you know about this disease, the easier it can be to manage. Our reference library provides links to additional resources and community blogs about feline diabetes to help keep you connected.

Hypoglycemia vs. hyperglycemia

Hypoglycemia

Hypoglycemia is the medical term for low blood sugar. Diabetics have the opposite problem of hyperglycemia, or high blood sugar.

Diabetic cats can develop hypoglycemia (low blood sugar) when their diet and treatment is managed incorrectly. Symptoms of hypoglycemia include:

Abnormal hunger or disinterest in food
Restlessness
Weakness or lethargy
Shivering
Staggering or uncoordinated movements
Loss of eyesight
Disorientation

If your cat experiences symptoms of hypoglycemia it is recommended to contact your veterinarian for advice. In the meantime, you can try feeding the cat some of its normal food. If the cat is unwilling to eat, try encouraging the cat by offering a small amount of corn syrup on the food. In cases of extreme condition, contact your veterinarian and take your cat in immediately.

Hyperglycemia

Hyperglycemia is when your cat's blood sugar levels are too high, resulting in the primary symptoms of feline diabetes, including:

Increased thirst
Sudden increase in appetite
Sudden weight loss (despite an increase in appetite)
Increased urination
Increased lethargy

Generally, hyperglycemia is not life-threatening and can be controlled through administering insulin. Your veterinarian will work with you to develop a regimen for testing and controlling your cat's blood sugar levels to avoid hypo- and hyperglycemia.

Living with a diabetic cat

Each diabetic cat responds differently to different therapies. Some cats are easier to regulate; others require more complex types of treatment. Some cats can be treated successfully through changes in diet and with oral medications. In cats with more severe diabetes, insulin injections may be required for the remainder of their lives.

In general, treatment for diabetes falls into three categories:

Insulin injections
Oral hypoglycemic medications
Diet

Home monitoring & testing

Ongoing and frequent home monitoring of your cat's glucose level is important both for ensuring that diabetes is under control and the long-term health maintenance of your pet. Home monitoring usually results in less stress on the cat and allows for closer, more precise control of blood glucose levels on a regular basis, which helps avoid the risk of hypoglycemic episodes.

Home testing of glucose levels can be done with a similar type of blood glucose monitor used by humans. This method requires a small sample of blood that is taken from the cat for testing and generally provides an immediate reading of your cat's blood glucose level.

In addition to monitoring glucose levels through the blood, caretakers can use urine glucose monitoring. However, urine glucose monitoring is generally not as accurate due to the lag time for glucose to go from the blood to the urine in the cat's body.

It is recommended to consult with your veterinarian on the best way to monitor your cat's glucose. They can also provide valuable advice on which type(s) of monitors work best in cats, as well as train you on how to use and interpret the test results.

When at home, you also should continually be aware of your cat's appetite, water consumption and urine output to determine what is normal behavior. Changes in your cat's eating and drinking habits, weight and urine output can be a sign that there is a problem and veterinary attention is needed.

Diet

Along with insulin and oral medications, maintaining a proper diet for your cat is important in a successful treatment program. Obesity is a major risk factor for diabetes and insulin sensitivity in most cats. If your cat is overweight, you and your veterinarian can tailor a safe weight loss regimen. Some cats respond better to carbohydrate-restricted diets ( Catkins diet ) and some respond well to high-fiber, complex carbohydrate rations. In fact, some cats have been able to get off insulin after losing weight & staying on the low carb diet.

In addition to the type of diet fed, the feeding routine also is important, especially for cats receiving insulin injections. Ideally, a cat should be fed half its daily food requirement at the time of each injection, with the rest available throughout the day. When and how much to feed your cat should be discussed with your veterinarian as other factors may impact this process, (e.g., number of insulin injections/day or living in a multi-cat household).

Insulin injections

Most diabetic cats require insulin injections under the skin once or twice a day, depending on the diabetic severity, type of insulin used, dose, diet and other factors. Because each cat reacts differently to insulin, your veterinarian will most likely perform a blood glucose profile at various time points during the day to determine the proper insulin dosage and treatment program. Insulin dosage may change over time as the cat ages, and you may need to adjust the dosage based on new blood glucose profiles, test results and how the cat responds to therapy. It is very important to consult with a veterinarian before making any changes to your cat's insulin dose. Many factors are involved with a decision to increase or decrease dose and you want to avoid causing hypoglycemia in your cat. There are reports of some cats reverting back to being non-diabetic after being on certain insulins, as glargine.

There are several different types of insulin available for use in managing your cat's diabetes. Some of the most common include protamine zinc (PZI) insulins, lente insulins, Humulin® and other human-type products.

Oral hypoglycemic medications

Some healthy diabetic cats can be successfully treated with orally administered hypoglycemic medications that lower blood glucose levels. Often, the use of these medications requires frequent glucose monitoring to ensure the best results, and many cats still require insulin injections to achieve the highest level of control.

Ketones

Ketones are waste products of fatty acids that may build up in the bloodstream and urine of cats with diabetes. Ketones develop when the cat's body burns fat, instead of glucose, to fuel its body.

If your cat accumulates too many ketones in the body, diabetic ketoacidosis (DKA) may occur. This is a serious condition altering the pH and blood chemistry of your pet, and should be treated immediately.

Signs your cat may have diabetic ketoacidosis:

Drinking excessive water or no water
Excessive urination
Diminished activity
Not eating for 12 hours or more
Vomiting
Lethargy or depression
Weakness
Dehydration
Ketone odor on the breath (may smell like nail-polish remover or fruit)

Simple urine tests will alert you to the presence of ketones. If you discover ketones in your cat's urine sample, check to see if your cat is exhibiting any of the symptoms of diabetic ketoacidosis listed above. If the cat is generally alert and well-hydrated, simply treat the cat with your normal insulin regimen, provide the cat with continual access to food and water, and monitor the cat for signs of diabetic ketoacidosis. If the cat develops signs of DKA, contact your veterinarian immediately.

For more information on feline diabetes, please go to www.MyCatHasDiabetes.com

References

Boehringer Ingelheim Vetmedica, Inc. What is Feline Diabetes?
www.MyCatHas Diabetes.com 2013.
Nunn, Lyn. Feline Diabetes: Cat Diabetes Types and Causes
http://www.catbreedsjunction.com/feline-diabetes.html 2013.