[Ellie May]

There is some room to use natural remedies to prevent fleas since they aren't that dangerous short-term and are visable. On the other hand, that isn't the case with heartworms. There is no way to be certain that pups arent being bitten and there is no spray or shampoo that will stop it 100% of the time. I know there are sites on the web that would try to downplay the risk of heartworms, but it is subjective. I would rather prevent heartworms and risk damage from long term use of milbemycin than I would leave Ellie open to heartworms and have to put her through imidicide therapy.