Maintaining good nutrition is a vital component in the overall care of cats with chronic kidney disease (CKD). Appetite is also a component of perceived quality of life in cats. Unfortunately, approximately 21-92% of owners of cats with CKD report their cat having an abnormal appetite. There are many reasons why a loss of appetite can occur in CKD. Appetite regulation is complex and involves a balance of appetite-stimulating and satiety-inducing substances. Two hormones, ghrelin (appetite-stimulating) and leptin (satiety-inducing), are largely involved in the regulation of appetite and the desire to eat. In humans with CKD, the ratio of these hormones are affected by the kidneys inability to eliminate them from the body, and the result is a greater prevalence of substances that suppress appetite. The goal of this study is to determine whether an imbalance of these hormones occurs in cats with CKD and whether it is associated with a decreased appetite. In order to accomplish this goal, small blood samples will be used to measure the relative concentrations of ghrelin and leptin in normal cats and cats with CKD. Data acquired from this study will allow us to better understand inappetence in CKD and modify the treatment of cats with CKD in the future.