Interceptor (milbemycin oxime) Heartworm Flavor Tabs for Dogs and Cats are used to prevent heartworm disease, control adult hookworms, and remove and control adult roundworm and whipworm infections in dogs and puppies. Prevents heartworm disease and removes adult roundworms and hookworms in cats and kittens. Interceptor Flavor Tabs for Dogs and Cats contain milbemycin oxime in a palatable formula given once per month. Approved for dogs and puppies at least 2 lbs and 4 weeks of age. Approved for cats and kittens at least 1.5 lbs and 6 weeks of age. Milbemycin.