Will Falconer, DVM Moderator
Hi Chloe,
HW testing should be a yearly event if you live where this parasite lives. I recommend that in my drug free heartworm book that you mentioned. It's important to realize that the drug given by injection (Pro Heart) was recalled after many dogs died several years ago. It, like the flea drugs is a pesticide. It poisons the larvae, and the hope is not the dog while it's at it.
Be sure to visit my Non-Toxic Flea Control page. You'll see how they can be controlled well without risk to pets or people.
Welcome aboard. Take your time, and change one thing at a time. Good start is stopping future vaccines. Then, take pest prevention to a safe level. Then, look at diet improvement.