I have had elderly sims be saved from death with the deathflower and it's been shown in several of the stories on this forum so I know that fact to be true. As for the loving animal, if you have pets, animals can "harass death" to save a Sim. This happened in my dynasty as well as Katluvr's Fae Dynasty.
Let us know how long they last if you don't give up and kill them off first.