Chronic kidney disease (CKD) is one of the most common diseases in aging dogs and cats, with very serious health consequences. Our kidney function test measures the serum concentration of Symmetric dimethyl arginine (SMDA). The International Renal Interest Society (IRIS) recognizes SDMA is a biomarker of renal function which can detect the disease months or even years earlier than traditional tests such as creatinine or BUN.1,2 Early detection and monitorinng of this disease makes it possible for veterinarians to provide timely treatment and improve their patient’s quality of life.