I have previous experience with a heart murmur and suggest that if you are wanting to educate yourself, you need to understand how the pharmaceutical meds will help before ruling them out. Ask your vet for the names of the medications and then do your own research on the meds without relying on what the vet says. I think you will find these meds will help her heart function and make her breathing easier. The meds really helped my girl for several years. With all the information on the internet now, there is never any reason to do just what the vet tells you without researching it first and understanding what you are dealing with.
I researched a number of supplements, herbs, and amino acids after my girl progressed from grade 1 to 2. If you want to give supplements, find a holistic vet to consult with, if you cannot drive to one. I am a firm believer in holistic medicine, but cannot recommend just using a holistic approach for a murmur that has progressed to a grade 3/4.
