Some researchers such as Morone & Weiner (2013) think that pain should be considered the "fifth vital sign", along with temperature, blood pressure, pulse and respiratory rate. However, when you think about a cute little creature with feline leukemia, there should be another, most important vital sign: love. Most veterinaries should immediately consider euthanasia for a FelV+ cat, but they never consider how much you can love your cat. When Opus made it to my home, in early 2013, I never thought I would develop such an intense feelings towards him. It was until I discovered that he would rather sleep in my scattered clothing than in a very comfortable cat bed that I discovered how much he loved me back. I don't mind if Opus will make it for years or a couple of months, but the time I spend with him, and the time that my other cat, Mefisto, spends with him, is vital for us. I will not euthanize Opus unless he is in pain. But thanks to TCyte, http://tcyte.com/ he has remained symptomless for almost a year now.