My first Cavalier Rudee lived to 12 tears and 9 months. She was on Vetmedin and furosemide from age 5 onwards.
Taking on a rescue is a totally different journey and one I would recommend whole heartedly . It's all the little things that happen , that you don't expect from a rescue; like playing with a toy for the first time or walking proudly and confidently up to a stranger ........................ exhilarating moments!!! I can honestly say, with my hand on my heart, that taking a rescue Cavalier into your home has got to be one of the most rewarding experiences ever.
Whatever you decide , I wish you and your (soon to be) new charge the very best