Diagnosis - Diabetes
Diabetes mellitus is a commonly diagnosed endocrine disorder in dogs and cats. There are two types of diabetes mellitus, just like in people. Type I is the most common in dogs and requires insulin for treatment. Type II is more common in cats than dogs and can often be resolved with diet and weight loss (but may also require insulin). Cats do suffer from Type I diabetes as well.
Insulin is produced by the cells of the pancreas. Insulin controls the level of sugar or glucose in the blood by regulating the entrance of the glucose into the cells. The cells of the body need the glucose for energy. If the pancreas does not produce enough insulin, or the cells become resistant to the insulin, the cells can't get the glucose (energy) they need. The body gets the signal to take in more food and to use fat and protein stores for energy but the cells just can use it. The blood sugar level gets higher and higher and the cells can't use it. The pet becomes extremely thirsty and drinks water excessively to try and dilute the glucose circulating in the blood.
Diabetes (Type I) has several potential causes. Immune-mediated destruction of the pancreas destroys the cells that produce insulin. It is not known what triggers the body to attack its own organs, such as the pancreas. Some infections can cause diabetes and even some medications can cause it (steroids and hormones).
The most obvious symptom is a massive increase in water intake. Pets with diabetes will drink almost continuously. They will also need to urinate more frequently and will most often eat more than usual while losing weight. Other symptoms are a poor hair coat and dandruff, and cataracts in dogs.
Based on your description of your pet's symptoms, your veterinarian will run blood tests and urine tests. High glucose levels in the blood and urine along with the symptoms confirm the diagnosis. Cats will sometimes have elevated blood glucose and even glucose in their urine without being diabetic. This is a common stress reaction in cats. An additional test called a serum fructosamine can help make the diagnosis in cats.
Insulin-dependent diabetes mellitus must be treated with insulin injections. This is especially important for dogs that have not developed cataracts. Precise control of the blood glucose levels will help prevent this devastating cause of blindness from developing. A low dose of insulin will be chosen as a starting point and your veterinarian will perform a glucose curve (multiple blood glucose levels drawn throughout the day) to determine the appropriate amount of insulin. Getting your pet regulated may be very difficult (and expensive) initially. Weekly glucose curves are necessary to find the best amount of insulin to control the diabetes. There are several different types of insulin availabe and your veterinarian may need to try more than one type to get your pet regulated. Cats don't necessarily need the glucose curve like dogs do. Some cats are so stressed by their visit at the veterinary office that an accurate curve can't be made. Testing one blood glucose level at an outpatient visit, along with knowing the number of hours since the last injection and whether or not there are any symptoms of diabetes, will help your veterinarian determine if the insulin dosage should be changed.
Some pets are very sick with diabetes. If the disease has progressed to this point, intensive care in the veterinary hospital is needed. With time and a lot of effort on the part of you and your veterinarian, even very sick pets with diabetes can make a recovery to the point of going home for continued therapy.
Pets treated with insulin for diabetes require much more care at home and at the veterinary hospital than other pets. Special diets may be prescribed and your pet will be on a strict schedule. We used to perform glucose curves in the hospital, a day long monitoring of blood sugar levels. However, there are now some new in-home monitoring devices that can more accurately measure blood sugar levels without the stress of a day in the hospital. Your veterinarian may ask you to get more involved in the monitoring and management of your pet's disease. As with any chronic illness, pets with diabetes may suffer from more frequent health problems and require more care for things other than their diabetes.
Prognosis is fair to good, depending on many factors. Other concurrent illnesses can complicate treatment. Treating a diabetic pet is very rewarding, but is time consuming and costly. Do your homework. The website www.petdiabetes.org offers great information (including support groups) for people whose pets have been diagnosed with this disease.
Please note that this information does not replace onsite, professional, veterinary care. It is solely for educational purposes. Your pet's medical condition should be evaluated by a veterinarian before any medical decisions are implemented. If there is a potentially life-threatening emergency involving your pet, take your pet to a veterinarian or veterinary facility immediately.
Veterinary Technical Services Department