Thank you for your question. When a 14-year-old cat stops eating, or has a decreased appetite, this is a cause for concern. Decreased appetite indicates that something is not right, even though a cat may still seem fairly normal at this point. Many medical conditions can decrease the appetite, including diabetes, kidney problems and hyperthyroidism. These are all fairly easily diagnosed with blood tests. Since early detection offers the best chance for the most effective treatment, we would suggest that you have your cat examined by your veterinarian as soon as possible.