I have a heart murmur myself. It's caused by a mild malfunction of a valve and doesn't affect me at all, except that it's noted on my medical charts. I've undergone many procedures, including anesthetics, before it was even detected when I was in my 30s! I am now a retiree - no heart issues yet.
So I think it all depends on the cause of the murmur. I'm wondering whether cats can have valve insufficiencies the same as people do. I do have a Manx with cardiomyopathy. But to me, that's a huge step beyond a minor murmur.
Best of luck with whatever you decide to do, and bless you for rescuing these two.
Last edited by faranya; February 24th, 2009 at 10:07 PM.