Leslie, I don't think Kersey and Graham are in danger of getting Heartworms. If they were outside dogs, then I could see why you would have to worry. But they are inside dogs.

Drake gets his HW preventative in a shot that last 6 months! My vet send me a weekly reminder a month prior to the date Drake's supposed to get his next shot. It costs just as much as the tablets do and it is more convenient and easier to remember.