Interceptor (milbemycin oxime) Flavor Tabs(26-50lbs Dogs, 6.1-12lbs Cats) prevent heartworm disease, control hookworm infection, and remove and control roundworms and whipworms in dogs and puppies. Interceptor Flavor Tabs prevent heartworm disease and remove hookworms and roundworms in cats and kittens. Pets should be tested for heartworm disease before starting this medication.For dogs and puppies over 4 weeks of age weighing from 26 to 50 pounds, and cats and kittens over 6 weeks of age weighing from 6.1 to 12 pounds. Safe to use in pregnant and nursing dogs.NOT RECOMMENDED FOR breeding, pregnant, or nursing cats. The convenient Remind Me system sends one dose of the medication out each month to keep your pet’s treatment on schedule.