The statin family of drugs, including Lovastatin and Lipitor are best known for their ability to lower blood cholesterol. However, over the past decade, there has accumulated a significant body of evidence that demonstrates that they can also halt the progression of chronic renal disease in people. Experiments involving kidney disease in rodents have confirmed this phenomenon. Although the potentially beneficial effects of statins in dogs with renal disease has not been evaluated, there is one statin (Lovastatin) that has been determined to be safe for use in dogs. The proposed study, which will be a multi-center double blinded, controlled clinical trial, is designed to evaluate the effect of Lovastatin on the progression of chronic renal failure in dogs. A total of 50 dogs with chronic kidney failure will be evaluated with half receiving Lovastatin and half receiving a placebo. Over a period of twelve months, the dogs will be followed with quarterly blood work, urine analysis and physical examinations. We hypothesize that the study will identify a beneficial effect of Lovastatin in dogs with CRF and that will lead to new treatment protocols for dogs suffering from this debilitating disease.