Diabetes mellitus is one of the most common endocrine diseases of cats but relatively little is known about the factors responsible for the development of the disease. Glucose (blood “sugar”) is abnormally elevated in diabetic cats and it is well known that even normal cats can develop elevated blood glucose (“stress hyperglycemia”) under some circumstances, such as a stressful event. The propensity of cats to develop stress hyperglycemia along with other peculiarities in the regulation of blood glucose suggests the possibility that cats may possess unique mechanisms for glucose control. Glucokinase (GK), which is found in the liver and pancreas, is an important enzyme in glucose metabolism in some species. Absent or abnormal GK produces diabetes that can range from mild to severe. GK activity is reported to be largely absent in normal cats. The purpose of this study is to demonstrate that normal cats possess the gene to allow them to produce GK enzyme and to determine whether GK is found in the liver, pancreas, or both tissues. The results of this study will shed light on the normal glucose metabolism of cats and provide the foundation for additional studies into the role of GK in the development of feline diabetes.