Tracy Brown wrote: >Just wanted to clarify.... There are NO heartworm preventatives. Only >heartworm insecticides which kill the larvae already circulating in >the blood. When you give a dose of heartworm meds, you are killing >heartworms that are already present before they grow into the adult >heart-clogging worms. There is no medicine that PREVENTS heartworms. I think you're into sematics. The drugs given ARE actually preventives. They PREVENT the onset of heartworm DISEASE. The shortcut of calling them preventives is completely acceptable. Katharine Florida [Posted in FML 7044]