Advocate Flea, Heartworm And Worm Treatment for Dogs Advocate is the closest thing to a vaccine against Australia’s most common parasites. An easy-to-use spot-on, it is applied monthly. The super ingredients in Advocate provide fast relief from fleas, prevent deadly heartworm and protect both your dog and your family from most gastrointestinal worms. Advocate creates a flea-free home fast. It stops fleas biting within 3 to 5 minutes, killing adult fleas and their larvae within 20 minutes – breaking the flea lifecycle. With monthly use it also protects your dog from the danger of heartworm infections. Plus Advocate takes care of worming worries. It kills up to 100% of hookworm, roundworm and whip worm, and prevents reinfestation. It’s water-resistant and even prevents mites and lice. It all adds up to the most thorough parasite protection available for your dog.