Most people have heard of diabetes. It is, after all, a not uncommon medical condition amongst our human population. But many people are probably unaware that diabetes strikes our pets as well - there are any number of cats and dogs out there having daily injections of insulin so that they can continue to lead relatively normal lives.
So just what is diabetes? The most common form is diabetes mellitus, which is basically a failure in the production of insulin, a hormone that controls the way glucose is used in the body. Glucose, produced from the digestion of carbohydrates, is essential to every cell in the body. But without insulin, the cells can't extract the glucose - as well as some other nutrients essential to the proper functioning of the body - from the blood.
This means that the glucose levels in the blood rise dramatically - a condition known as hyperglycaemia. Some of this excess glucose spills over into the urine, drawing with it much more fluid than is normally the case. In fact, the first sign people often see with their affected pets is that they urinate more frequently, and, in an attempt to maintain their fluid levels, they also drink a lot more than usual.
They'll often become very hungry as well. Once again this is due to the failure of glucose to enter the cells, particularly those cells in the brain that control appetite.
Lack of insulin also contributes to the breakdown of fat and muscle within the body so that, although animals are often eating more than usual, they actually lose weight.
So there are four classic signs of diabetes - increased urination, increased thirst, increased appetite and a loss of weight, but it must be remembered that each of these symptoms may have other causes as well - diagnosis of diabetes depends not only on the symptoms, but also on laboratory tests on both blood and urine. A fifth sign which can occur as a result of the high blood glucose levels is the development of cataracts leading to blindness.
Animals can get diabetes at any age, although it is more common in those that are middle-aged and older, and much more common in pets that have, at least at some stage, been overweight. Dogs are more commonly affected than cats. Sometimes the disease seems to occur for no apparent reason, but it can also be a result of other disease processes. An example of this is pancreatitis, or inflammation of the pancreas, which is the body's source of insulin. If enough of the pancreas is damaged, the production of insulin falls below the necessary levels.
Some drugs, too, can contribute to diabetes, especially if used over long periods. Cortisone, a commonly used anti-inflammatory drug, is one, while the hormones in some contraceptive tablets are another.
The only practical way to treat diabetic animals is by injecting them with insulin once or twice a day. Great care is needed in the early stages because too much insulin will lead to hypoglycaemia, when the glucose levels fall too far, initially causing weakness, but ultimately, if untreated, resulting in convulsions and coma.
So initial treatments are often done in the veterinary clinic, until a dose rate is established, or at least until the high glucose levels have begun to fall. Owners are then taught to inject the insulin under the skin of their pets.
Diet is extremely important now. In order to establish and maintain the correct dose of insulin, owners need to ensure that their pets' calorie intake does not vary from day to day - no extra titbits unless they're extra every day! Prescription diets for diabetes are available - these contain the relatively high amounts of fibre important for affected animals.
As well as all this, owners must regularly check the glucose levels in their pets' urine - any changes necessitate a visit to the vet for further blood tests.
Some animals settle quickly into an insulin regime and only need occasional checks. With others, it is more difficult to establish an insulin dose, and this may sometimes be due to the animal's having other problems as well. However the treatment goes, it involves a lot of input from the owner. Daily injections, strict diets, checking the urine and regular veterinary checks are not for everyone, but for those who are happy to make that degree of commitment, the result - at best, the restoration to near normality of a beloved pet - can be very rewarding.
- Virginia Williams & Bert Westera