There are some highly effective treatments which will kill worms. These are available as liquids, pastes, tablets or powder. However, not all the products are equally good and some work against certain types of worms and not others. Your vet will be able to advise you on which product is best for your dog. Worms are so common that it is safe to assume that all puppies, dogs with fleas, and animals which regularly catch wildlife will be infected. Puppies should be treated with wormers every two weeks, from two weeks of age. Your vet will then advise you on the recommended interval which will depend on the product used. Older dogs should be treated about every three months. You should discuss with your vet the most appropriate treatment regime for your pet