Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

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Diabetes: A Common Problem for Pets

Pet Column for the week of July 10, 2006

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
Kim Marie Labak
Information Specialist

Millions of Americans have diabetes and don't know it, since many people with the disease may not recognize the signs, according to Dr. Thomas Graves, veterinary internal medicine specialist at the University of Illinois Veterinary Teaching Hospital in Urbana.

Similarly, in animals, "often we don't diagnose diabetes until it causes it causes outward signs such as urinary problems," but the disease can exist well before a pet owner notices these signs.

As in humans, diabetes in pets can vary along a continuum, from a sometimes transient form of the disease, seen in cats, in which the pancreas produces insulin but the body does not respond properly (known as insulin resistance), to a more lifelong disease resulting from an insulin deficiency, as seen in most diabetic dogs and cats.

Dogs tend to get diabetes early in life, resulting from a lack of insulin production and secretion by the pancreas. This form of diabetes is primarily influenced by genetics, and is managed with lifelong insulin supplementation. Cats tend to get diabetes later in life, and several factors, including genetics, body weight and diet, can influence resistance to insulin. Diabetes is seen more commonly in certain breeds of dogs, including Standard and Miniature Schnauzers, miniature and toy poodles, and Samoyeds and in middle-aged to older obese cats. Any dog or cat, however, can be afflicted with the disease.

Insulin helps cells absorb and use glucose for energy. Insulin deficiency or insulin resistance leads the body to think there is not enough glucose in the blood when there actually is plenty, and the body signals the liver to make more glucose by breaking down body fat and sugars stored in liver and muscle tissue. This increases glucose and acid levels in the blood, which can lead to life-threatening problems.

When glucose in blood rises high enough, it spills out into the urine and causes the animal to urinate more frequently, and can lead to severe dehydration. Constantly high levels of glucose can also lead to permanent damage to the insulin-secreting cells of the pancreas.

As with many diseases, the signs of diabetes may be variable and subtle--this is why many owners may not recognize the disease in their pets. A diabetic animal may urinate frequently and drink unusually large amounts of water to compensate for dehydration, and may lose weight despite a normal or increased appetite.

Diabetic animals lose weight because the body isn't using glucose and is trying to use body fat as a source of energy. If diabetes goes untreated, this accelerated breakdown of body fats can increase the acidity of the blood, which can cause neurological problems. If an animal feels very ill, it may become lethargic and actually have a decreased, rather than increased, appetite.

Owning a pet with diabetes can require some tenacity. Dr. Graves explains, "Diabetes is difficult to control in humans, and more so when dealing with pets. The insulin treatments we use are made from other species (humans, cows, and pigs) and a lot of the drugs that people take for diabetes to lower glucose don't work in animals and/or have more side effects, especially for cats."

In addition to injectable insulin, special diets may also help control diabetes. Some veterinarians postulate that low carbohydrate diets may help control diabetes in pets as in humans, but there is no hard data to support this. Graves says, "Low-carb diets are worth a try, but more research needs to be done to determine whether they really make a difference for diabetic pets."

Keeping a cat from becoming overweight can greatly reduce its risk of developing diabetes since the disease is highly associated with obesity. It is important to always consult a veterinarian before starting a weight loss plan for a cat, since drastic weight loss can cause a life-threatening liver condition called hepatic lipidosis, or "fatty liver." This is a condition in which the liver becomes overwhelmed trying to filter out the fats in the blood that are moving out of body fat storage. If an obese cat successfully and safely loses weight, diabetes may recede, but if the diabetes and high blood glucose persists, the disease can progress.

Once diagnosed, a diabetic animal is usually put on a regimen of daily insulin injections and regular check-ups to see if the insulin dose needs adjustment.

For more information about diabetes and pets, consult your local veterinarian.