Euthanasia is defined as the deliberate painless ending of the life of an animal that usually is old, suffering from an incurable disease or injury, intractably vicious or dangerously aggressive and untrainable. Also called “mercy killing,” “putting a pet down” or “putting an animal to sleep,” euthanasia is never an easy topic to discuss. However, for many owners, this is the process that lets them say goodbye to their beloved pets in a safe, peaceful and, for the cat, painless fashion. People without a medical background may not fully understand the euthanasia process. This can cause uncertainty, confusion and potentially unnecessary heartache for owners. While it may be uncomfortable to learn about how cats are humanely euthanized, knowing what to expect, including what could possibly go wrong, can help owners prepare themselves for this difficult, but important, event.