If you don't control a flea problem at the same time as worming, your cat is almost certain to be re-infected. There are about 8 different types of intestinal worm that can infect cats in NZ, and it is not always easy to spot the symptoms.
Both Drontal Cat and Drontal Cat XL Tablets will kill every type of intestinal worm your cat is ever likely to get, and both will do so with a single dose, and without having to starve your cat first. The only difference is that Cat XL Tablets are specially formulated for cats between 4 - 6kg, so that most big cats can be treated with a single tablet.
To avoid worms reaching maturity and affecting your pet's health, and to reduce public health risks, you should worm your pet regularly. Worming at least every three months with Drontal will reduce this risk, but ask your vet who will be able to evaluate your pet's health and your family's requirements and advise you on a specific worming routine for your pet.