Will Falconer, DVM Moderator
That's a whole lot of writing, Rick, and I can only say that I see a flaw in your thinking. There are two things done towards heartworm: prevention, conventionally with risky drugs, and treatment of dogs who HAVE heartworm, with even more risky drugs.
Make no mistake. If you had HW positive dogs and they were treated, they were likely given significantly toxic, most often arsenic based drugs, Immiticide being the latest version.
Life has no guarantees. It's biology, not auto mechanics. We all try to study, learn what works for others, investigate and decide where our comfort level will allow us to go, in our own health and those of our animals.
I wish you all the best in your pursuits of natural health. Take it a step at a time and don't expect your conventional vet to see things like I do.