Diabetes Mellitus (sugar diabetes) is a common endocrine disorder in middle- aged to older cats.
There is a higher incidence in overweight cats, and males outnumber females 1.5 to 1. Insulin is a hormone produced by the pancreas that allows glucose (sugar) to be utilized by the cells in the body. Body cells need glucose as fuel just as automobiles need gasoline to function.

A small percentage of cats will become ketoacidotic. This is a serious and life-threatening syndrome caused by the production of ketone bodies in the liver. The ketones are produced when the body attempts to metabolize fat and protein in an effort to manufacture more glucose. This process causes acidosis of the blood and electrolyte disturbances which can lead to death.

Clinical Signs:

Excess glucose in the blood will "spill" into the urine carrying water with it causing excessive urine production. To prevent dehydration, the cat will increase his water intake. Weight loss is always present despite increased appetite. Often an owner will think the cat’s weight loss program is finally working. As the disease progresses vomiting, loss of appetite (anorexia), weakness, dehydration, hair and skin problems, kidney and liver disease, cataracts, and potentially ketoacidosis may become evident. In rare cases, the cat will develop a nerve disorder where he walks down on his hocks ("ankles"). This may or may not resolve with treatment.

Diagnosis:

Elevated blood glucose, glucose in the urine, and weight loss are needed to diagnose diabetes
mellitus. A thorough physical exam and blood testing are needed to assess the overall health of the patient and rule out other conditions.

Treatment of Uncomplicated Diabetes Mellitus:

The treatment of diabetes mellitus in the cat initially involves a commitment of time and dedication. Management of a diabetic cat can be frustrating, especially early on. However, it can lead to a stronger owner-pet bond and be a very rewarding experience. With proper therapy, your cat can have a happy, long, and comfortable life. There is a lot to understand about the disease and its management. The following sections will provide important information regarding the care of your diabetic cat.

Medications:

Normally insulin is needed to regulate the diabetes. Humulin N insulin is selected first because it
seems work best in cats. Unfortunately, it is often necessary to give the insulin twice a day or switch to a different insulin type.

Administration of Insulin:

You will be instructed how to draw the appropriate amount of insulin into the syringe and how to give the injection. It is advisable that all family members or friends that will be assisting in the
administration of insulin be present.

Diet:

Diet is also an important part of the management of diabetes. We recommend all cats eat Purina DM (DIABETES MANAGEMENT™ BRAND FORMULA). The role of dietary management in feline diabetes mellitus is to provide a proper balance of total nutrients while meeting the special dietary needs of the patient. Cats are unique in their requirement to metabolize high concentration of dietary protein. A high percentage of protein is used for gluconeogenesis. The increase concentration of high quality protein in this diet provides the cat’s essential amino acid requirements and a substrate for glucose production. With glucose production from dietary amino acids, the carbohydrate content of the diet may be dramatically reduced as with this formulation. Glucose derived from hepatic gluconeogenesis is delivered to the bloodstream at a slower rate compared to the release of glucose from digestion of dietary carbohydrate. The result is a more consistent, steady release of glucose and the potential for reduced insulin requirements.

This high-protein, low-carbohydrate diet fits a cat’s unique metabolism. This formulation helps to
manage glucose levels in diabetic cats while meeting their special dietary needs. This diet is authorized for prescription and sale only by veterinarians.

The cat’s normal feeding habits must be considered when formulating a diet plan. Ideally, he should eat small frequent meals to prevent wide fluctuations in the blood glucose. If the cat is a nibbler, the appropriate amount of food for a 24 hour period may be left out. This is the ideal situation. If your cat is gluttonous, he should be fed small frequent meals. If this is not possible, he may be fed twice a day. Give one half of his daily requirement at the time of the injection and the other half 8-12 hours later to coincide with maximum effectiveness of the insulin. If insulin is being given twice a day, give one half at the time of each injection. A small amount of treats is usually acceptable, but should remain consistent on a daily basis.

Treatment of Complicated Diabetes:

Ketoacidosis, as previously mentioned, is a severe and potentially fatal complication of untreated or poorly controlled diabetes mellitus. These cats must be hospitalized and started on intravenous fluids. The objective of treatment is to rehydrate, decrease the acidosis of the blood, correct electrolyte abnormalities, and decrease the blood glucose levels to prevent further production of ketones. Often these cats must be referred to one of the areas 24 hour critical care centers. Many times there is another disease process causing this complication.

Care of Insulin and Syringes:

1. Insulin does not have to be constantly refrigerated. It is stable for 30-60 days if kept from temperature extremes and sunlight. Since only a small amount of insulin is needed, we recommend refrigeration so the insulin will remain potent until the expiration date.
2. Remember to check the expiration date.
3. When purchasing a new bottle of insulin, please verify it is the correct type.
4. Discard the bottle of insulin when the fluid level is even with the bottom of the label. This is necessary because it is impossible to adequately resuspend the insulin perfectly each time. Therefore, the last insulin in the bottle may be either too concentrated or too weak. If after a long period of good regulation, the cat suddenly develops clinical signs of diabetes or hypoglycemia, check the insulin level in the bottle and the expiration date. If in doubt, get a new bottle.
5. Discard the needles and syringes in a container such as a plastic milk bottle and return it to us for proper disposal. Hazardous wastes are incinerated by a licensed and certified medical waste disposal company. There is a small fee for this service.

Home Monitoring:

1. We recommend you keep a daily log. Your observations are as critical in the evaluation of your cat as our physical examination and glucose monitoring.
2. Monitor his water consumption - i.e., are you adding more or less water to the dish.
3. Monitor the amount of urine produced. If you use clumpable litter, note whether the clumps are getting larger or smaller. Because uncontrolled diabetic cats produce such large volumes of urine, you should be able to notice less overall urine in the boxes even in a multiple cat household.
4. Does he urinate and drink more at night? This may indicate the insulin is not providing 24 hour control.
5. Monitor his appetite.
6. Watch for vomiting, changes in stool frequency and consistency, and the overall attitude of the cat.
7. Consistency in the timing of the insulin injections and caloric intake will make regulation of the blood glucose easier. A consistent amount of exercise is also advisable; however, this is unrealistic in most cats.
   

Testing and Procedures Used in the Regulation of Diabetic Cats:

The typical glucose range in a normal cat is 80 to 150 mg/dl. The goal of glucose regulation in the diabetic cat is to maintain the blood glucose levels between 100 to 300 mg/dl throughout the day. Within this range, the cat will be showing minimal signs of disease and the more serious side effects of diabetes (liver and kidney disease, cataracts, etc.) will be prevented. When insulin therapy is initiated, we will need to evaluate the cat every 14-21 days for a glucose curve. If regulation has not been achieved, additional testing will be required. Based on the test results, an increase in the insulin dosage (to twice a day) or a change of insulin may be warranted.

1. Glucose curve - During this test, the cat is admitted to the hospital and glucose values are obtained every 1-2 hours. The purpose of this testing is to determine the extent to which the insulin lowers the blood glucose level, if at all. Unless instructed differently, give the morning insulin and food on the day of the testing. Drop off should be between 7:30 to 8:00 AM unless the insulin is normally given later than this. If the cat has food available all day, please bring the appropriate amount of food. If the cat is on twice a day insulin and the next dose is due while the cat is still with us, please bring the insulin with you. He will be dismissed just prior to closing.
   
   Drawbacks to this test - Cats are easily stressed and adrenaline can cause drastic increases in blood glucose levels even in non-diabetic cats. In these cases, stress hyperglycemia may be 300-400 mg/dl. The insulin will not produce the expected glucose-lowering effect and we have to determine if this is stress-induced or a resistance to the insulin. Other times we document an earlier than expected peak effect or dangerously low glucose levels before the body responds by producing excess glucose. If the cat normally nibbles his food through the day and does not eat while hospitalized, this may allow for lower than normal glucose values.
2. Fructosamine - This is a substance formed by the interaction of glucose with albumin which is a protein in the blood. This provides information on the glucose levels over the previous 1-3 weeks. This value is not affected by stress of a hospital visit. Once a cat is stabilized, this test is performed every 6- 12 months.
3. Other considerations - Often other inflammatory and infectious disease processes may make it difficult to regulate the blood glucose. The two most common problems are dental disease and infection of the urinary tract. Often a urine culture is performed early on and if there is a suspicion of infection, a course of antibiotics is given. Once a diabetic cat is stable enough to have anesthesia, almost all newly diagnosed patients will need to have a dental prophylaxis. Usually extractions are necessary. The excess glucose in the blood provides a wonderful food source for bacteria. It is also known that chronic diseases such as diabetes mellitus will suppress the immune system. For diabetic cats that cannot be regulated with insulin therapy, there are several rare diseases that will need to be ruled out.
   

Hypoglycemia (Low Blood Sugar):

This insulin reaction is due to a marked decrease in the blood glucose. If your cat is receiving once a day insulin, this is most likely to occur 8-12 hours after the injection. However, it can happen anytime. The same is true for cats on twice a day insulin. Signs include lethargy, listlessness, weakness, incoordination, seizures, and coma. If the cat is alert enough to eat, offer a high calorie canned food and allow him to eat as much as he wants. You may need to offer the food in small amounts over 30-60 minutes to prevent vomiting associated with rapid food intake. If signs do not improve in 15-30 minutes, call us or one of the after hours emergency clinics immediately. If the cat responds, please contact us before giving the next dose of insulin. If he will not or is unable to eat, rub 1-2 tbs. of Karo syrup on his gums (be very careful if he is seizing). Karo syrup should be kept for this purpose. Once this is done, call our clinic or the emergency clinic immediately and advise that you are on your way.

Many times hypoglycemia can be prevented by using a little common sense. If you notice that your cat is consistently acting sluggish or "off" at certain times of the day, you should schedule a glucose check at that time. He may be receiving an overdose. Also, if he is displaying signs of illness such as vomiting, not eating, listlessness, lethargy, etc., you should skip the scheduled dose until you contact us. Administering insulin to a cat that does not feel well enough to eat is probably the most common cause of a hypoglycemic episode. The cat should be evaluated because these are the same symptoms he will exhibit when his blood glucose level is dangerously high.