3. Revolution

Revolution is related to ivermectin, so it will kill fleas plus prevent heartworms. It can also be used to treat ear mites, some intestinal worms, a few species of ticks, and mange. Pups must be 7 weeks old to begin using this. You have to have a current heartworm test or start Revolution when your pup is under 5 months old to use this prescription-only drug. It’s a once a month topical product applied to the back of the neck. It is waterproof after 24 hours, but not shampoo-proof.