Diabetes mellitus, also known as sugar diabetes is a complex but common disease in which a cat's body either doesn't produce, or doesn't properly use insulin. During digestion, the fats, carbohydrates, and proteins that are consumed in the diet are broken down into smaller components that can be utilized by cells in the body. One component is glucose, a fuel that provides the energy needed to sustain life.
Insulin is a hormone produced in the pancreas, is responsible for regulating the flow of glucose from the bloodstream into the cells of the body. When insulin is deficient or ineffective, the cat's body starts breaking down fat and protein stores to use as alternative energy sources. As a result, the cat eats more yet loses weight. Additionally, the cat develops high levels of sugar in the bloodstream, which is eliminated in the urine. In turn, sugar in the urine leads to excessive urination and thirst. Cat owners often notice these four classical signs of diabetes mellitus: ravenous appetite, weight loss, increased urination, and increased water consumption.
Diabetes mellitus is generally divided into two different types in cats: insulin-dependent diabetes mellitus, and non-insulin-dependent diabetes mellitus. Approximately one-half to three-quarters of diabetic cats have and thus require insulin injections as soon as the disease is diagnosed. The rest however may ultimately require insulin injections to control their disease.
While diabetes mellitus can affect any cat, it most often occurs in older, obese cats. Male cats are more commonly afflicted than females. The exact cause of the disease in cats is not known, although obesity (the major predisposing condition), chronic pancreatitis, other hormonal diseases (hyperthyroidism, Cushing's disease, acromegaly), and certain medications (megestrol acetate and corticosteroids like prednisolone) have all been linked to the disease.
In addition to medication, an important step in treating diabetes is to alter your cat's diet. Obesity is a major factor in insulin sensitivity, so if your cat is overweight, you will need to help him lose weight. Your veterinarian can tailor a safe weight-loss program, in which your cat loses weight gradually. A high-fiber, high-complex carbohydrate diet not only can achieve weight loss if necessary, but is believed to help control blood sugar levels after eating. Some cats respond better to high-fiber diets and others to low-carbohydrate diets. Trial and error can help determine the best diet for your cat. Your cat's feeding routine is also important. While many cats are free-choice feeders, this may not be the ideal routine for a diabetic cat. Ideally, a cat receiving insulin should be fed half its daily food requirement at the time of each injection, with the unconsumed remainder available throughout the day. Food intake should be closely monitored.