A friend of mine had a cat who had Leukemia, and to this day she still cries when she thinks about her. They kept her alive as long as they could; IVs, force feeding, watching her waste away to nothing. When they finally put her down it really tore her up, but she says now she wishes she had put her down much sooner than they did. It wasn't pretty watching Kitty die. I know if it were me, I'd probably put my cat down, as much as it would break my heart. I don't think I could handle watching any of them go down hill that way. It would be better to have them PTS than to know that their quality of life is so low.

On the bright side, hopefully she's not positive so you won't even have to make the decision. Keep us posted!