For dogs up to 11kg (25lbs) Each pack contains 6 chewables, to be given as one per month for the prevention of heartworm. Heartgard Plus also controls roundworm and hookworm, but not tapeworm or whip worm. Heartgard Combo includes Paragard allwormer tablets to cover all worms. Rx required from US customers before shipment. Cannot be shipped to Japan.This is Australian registered product labelled in kilograms.Specific product information can be found by clicking more info and the detailed product specifications link Heartgard® is a registered trademark of Merial, a Merck and Aventis company. Detailed Product Specifications