Poor Marius....Poor you. {{{HUGS}}}

What you need to do is ask the vet what GRADE murmur did he hear? I am not an expert but 1, 2 or even 3 should not give you any reason to be concerned. It is something you monitor to make sure it does not get worse. 4 or 5 could mean bad news.

Willow has grade 3 heart murmur but he is fine. We have not done any extra test and he doesn't need medication or anything. We just monitor it to make sure it does not get worse.