Regulating diabetes mellitus in dogs and cats

Regulating diabetes mellitus in dogs and cats

Brush up on your clinical skills with this disease overview.
Mar 01, 2010

Many pets have diabetes mellitus and their owners don't even know it. The good news is that with the right insulin, patience and diligence on the owner's part, and your help, this disease can be effectively managed. More on diagnosis can be found by reading "Diabetes mellitus: What is it and how is it diagnosed?".

Managing diabetes

Diabetes is generally managed rather than treated. The exception is cats that still have enough functioning pancreatic beta cells. For these cats, diabetic remission is likely with aggressive diet and exercise changes along with insulin therapy. Dietary recommendations for diabetic dogs include feeding a dry food high in insoluble fiber and sticking to two equal meals a day given at regular intervals, preferably every 12 hours. For cats, feeding four times a day at regular six-hour intervals is ideal. Diets high in protein and low in carbohydrates are essential to help diabetic cats regain glycemic control. Uncomplicated diabetes can be well-managed long-term with diet, exercise, and insulin injections administered at home by owners.

Insulin basics

Insulin products are categorized based on their duration of action. Three general types of insulin are administered to dogs and cats: short-acting (regular or crystalline), intermediate-acting (NPH and lente), and long-acting (PZI and glargine). PZI (dogs and cats) and glargine (cats) are longer acting but still require initial twice daily dosing. Glargine insulin is slowly released from the subcutaneous tissues, so blood glucose values may take several days to begin adjusting downward when using this insulin. Owners may be apprehensive about giving their pets insulin injections. Having the owner practice an injection using a pinch technique and some sterile saline solution while you observe is a good idea. Owners should rotate injection sites with each injection to avoid the possibility of scarring, which can impair the absorption of the insulin administered at that site. Insulin products are either 40 U insulin or 100 U insulin, and they must be used with the correct corresponding syringe. Insulin should be given just after a meal, generally after the first meal of the day and again after the last. Owners should have detailed instructions on what to do if their pet misses a meal or eats only half of it.

Insulin will have different effects and durations for every individual. This is due to many factors including response to the individual insulin product, underlying medical conditions, and improvements in insulin resistance. Insulin therapy must be tailored to the individual patient. Owners should expect to do some adjusting of the dose or to change products along the way, either because a patient becomes unresponsive to the insulin originally prescribed or because of a Food and Drug Administration recommendation if a product was improperly produced. With persistence of hyperglycemia, owners will see a continuation or worsening of the clinical signs of diabetes. Owners should be looking out for signs of low blood sugar such as hunger, weakness, or ataxia and even seizures.

Blood glucose curves

In order to regulate a diabetic patient, its blood glucose is generally monitored, and a blood glucose curve, sometimes called an insulin-glucose-response curve, is generated. At-home monitoring may be more effective than generating curves in the hospital. Since glycemic control is highly dependent on sticking to a normal feeding and exercise routine (which is hard to do in a hospital setting), curves generated at home can provide better information about the animal's daily blood glucose concentrations. Today there are handheld glucometers that are accurate, easy to use, and require a small amount of blood. To generate this curve, the owner will measure the blood glucose concentration every one to two hours for an eight-to-24-hour period. In-hospital curves are common, especially if owners think that they are unable to perform one at home or if the patient is difficult to get blood from. For in-hospital curves, drawing the blood from the ears or medial saphenous veins to spare the commonly used intravenous catheter sites in case of crisis is recommended. While monitoring the patient's blood glucose, offer the patient plenty of water and frequent walks. (Click here to download a patient admission form for blood glucose curves.)

Multiple curves are often necessary to best regulate the insulin dose. If the dose changes because the pet's needs change, subsequent glucose curves are usually generated to access the change and regulation. Blood glucose curves should be generated one week after initiation of insulin therapy or anytime there is a dose or insulin product change. Keep in mind that a patient that is newly diagnosed or unregulated will probably need a longer curve to better track its response to the insulin.

Periodically, it is also important to evaluate fructosamine concentrations. As mentioned earlier, a fructosamine concentration can give an indication of the average blood glucose concentration over the previous one to two weeks.