Like diabetes in humans, this disease occurs in pets when there is not enough insulin (a hormone made in the pancreas) in the cat or dog's body to balance out the glucose in the their diet. Normally, food is broken down during digestion and the resulting glucose enters the bloodstream. Insulin is then released to regulate the blood's glucose levels. If your cat or dog isn't producing enough or any insulin, he or she will become diabetic. And if too much glucose builds up in his body due to the lack of insulin, it can become dangerous and even fatal.
Since diabetic pets do not get enough glucose transported into the body’s cells, cells can't function normally and tissues become starved for energy. Over time, lack of glucose causes the body to breakdown fat and muscle tissue.
The less common Diabetes Insipidus is a rare endocrine disorder that is treated with hormones and a low salt diet. A pet with this condition will be under the care of a specialist and isn't who we commonly think of when discussing veterinary diabetes.