Arlington Dog & Cat        

                              Hospital

In order to understand the problems involved in diabetes mellitus, it is necessary to understand something about the normal body's metabolism.

The cells of the body require a sugar known as glucose for food and they depend on the bloodstream to bring glucose to them. The cells cannot, however, absorb and utilize glucose without a hormone known as insulin. Insulin is produced by the pancreas. Insulin can be considered to be a key that unlocks the door that separates our cells from the sugars in our bloodstream.

Glucose comes from the diet. When an animal goes without food, the body must break down fat, stored starches, and protein to supply calories for the hungry cells. Proteins and starches may be converted into glucose. Fat, however, requires different processing that can lead to the production of ketones rather than glucose. Ketones are another type of fuel that the body can use in a pinch but the detection of ketones indicates that something very wrong is happening in the patient's metabolism. Ketones may be detected in the urine of starving animals as massive fat mobilization is required for ketone formation. Ketones can also be detected in diabetic ketoacidosis, a severe complication of unregulated diabetes so it is helpful to periodically monitor for ketones in a diabetic patient’s urine. The point, for now, is that body fat cannot be converted into glucose; in times of extreme fat burning (such as in starvation), ketones are a fat burning byproduct.

Urine dipsticks to detect ketones are available at most drug stores and can be used for home monitoring. The presence of ketones in urine for three days or more in a row warrants a visit to the veterinarian.

• The cells cannot receive glucose from the blood because there is no insulin to permit it.
• The body is unable to detect the glucose in the blood and is fooled into thinking starvation is occurring.
• Protein, starch, and fat break-down occur, as in starvation.
• Yet all along there has been plenty of glucose in the blood. In fact, by now there is a large excess of glucose in the blood as all resources have been mobilized. Still, without insulin, this bounty of fuel cannot get to the tissues that need it. 
• The normal kidney is able to prevent glucose loss in urine. In the diabetic animal, there is so much glucose in the blood that the kidney is overwhelmed and glucose spills into the urine and is lost.
• Glucose is able to draw water with it into the urine. This leads to excess urine production and excess thirst to keep up with the fluid loss in excess urine production.

• Excessive eating 
• Excessive drinking 
• Excessive urination 
• Weight loss

It is usually fairly clear from the history and tests showing dramatic glucose elevations in the blood (and usually glucose in the urine, too) that diabetes mellitus is the diagnosis. Some pets are able to substantially raise their blood sugars from stress (such as might occur when a sensitive, sick, and anxious patient goes the vet’s office). This could create misleading test results. If there is any question about the diagnosis, a test called a fructosamine level may be requested. This test reflects an average blood glucose level over the past several weeks so if this is also elevated, a one-time elevated glucose can be distinguished from the persistent elevations of true diabetes mellitus. The fructosamine test is also used in monitoring therapy for diabetes mellitus.

• Note that in dogs, sugars can enter the lens of the eye, causing rapid cataract formation. Because a cat’s lens is different, this phenomenon occurs only in dogs. 
• Another common symptom of diabetes mellitus is urinary tract infection. All the sugar in the urine makes the bladder an excellent incubator for bacteria. Antibiotics are necessary to clear up such an infection when it occurs and some monitoring may be needed to help detect these infections.

Regulation is achieved via a balance of diet, exercise, and insulin. Realizing that special diets are not always attractive to pets, there are some ideal foods that should at least be offered.

The most up-to-date choice for cats is a low carbohydrate high protein diet. These diets promote weight loss in obese diabetics and are available in both canned and dry formulations. For dogs, high fiber diets are still in favor as fiber seems to help sensitize the pet to insulin.

Avoid soft-moist diets as sugars are used to preserve them. Breads and sweet treats should be avoided. If it is not possible to change the pet’s diet, then regulation will just have to be worked out around whatever the pet will eat.

Links or further information you may wish to visit:

www.felinediabetes.com
www.pet-diabetes.com

A listserv for owners of diabetic pets is also available. To subscribe, send a message to majordomo@listserver.net and put the words “SUBSCRIBE PETDIABETES” in the body of the message.