Keep your dog free from the parasites that matter by killing fleas, heartworm, ticks and intestinal worms . Kills flea infestations, as well as ticks (Brown and the deadly Paralysis Tick), for the full month. Kills fleas and ticks within 4 hours. Break the flea life cycle by killing adult fleas before they can lay eggs - no further environmental infestation. Vet grade heartworm protection with Moxidectin that kills heartworm as well as intestinal worms. Safe for puppies from 8 weeks of age.