"Flavor Tabs are a monthly oral preventive that guards against heartworms (Dirofilaria immitis) and fleas as well as adult roundworms (Toxocara canis, Toxascaris leonina), adult hookworms (Ancylostoma caninum) and whipworms (Trichuris vulpis). As with other heartworm preventives, dogs must be tested for heartworm prior to using SENTINEL Flavor Tabs. In a small percentage of treated dogs, digestive, neurological and skin side effects may occur."