[LearsFool]

From the research I did on heartworms (was deciding whether or not to adopt a dog that tested positive), it’s a very rare affliction, distorted into epidemic proportions in order to sell the very expensive tests, preventatives, and treatments.

[Average Al]

Heartworm is hardly a rare problem! It affects the dogs lungs and heart and can kill a dog if not treated or prevented.

[justlurking]

It's hardly expensive for prevention.

We use Advantage Multi. We buy it from our vet, for about $10 an application, used monthly.