Interceptor Flavor Tabs are a chewable, beef-flavored tablet administered once a month to protect your dog and cat from the threat of potentially deadly heartworm disease, it also controls and treats against roundworms and hookworms and whipworms in dogs and roundworms and hookworms in cats when given every month.Dogs six months of age and older should be tested for heartworm disease prior to being put on a preventive program and tested annually thereafter.