Here is an article by Jan Rasmusen, the author of
Scared Poopless on heartwrom medication.
Heartworm Preventatives: Safety and Alternatives | Truth4Dogs
I consider
Scared Poopless to be a must have for any pet owner. Not only is it full of important up-to-date information about everything from vaccinations to providing for your pet in your will, it is a delightful read. It is written from the perspective of the author's little Maltese, Chicklet.