For medium dogs 11-22kg (25lb-50lb). Each pack contains 3 chews, one to be given monthly. For the prevention of heartworm, the long term control of fleas and the control of all intestinal worms including tapeworm. This is Australian registered product labelled in kilograms.This product should only be administered if your dog has been on a regular heartworm preventative program. Consult your veterinarian if you have not used a heartworm preventative on your dog before, or if there has been a period where treatment has lapsed.