Bob Martin Spot On Dewormer cat tapeworm treatment has been specially developed to make worming easy without the bites scratches and other problems associated with trying to give tablets to a cat. Simply apply the solution to the back of your cat's neck for fast effective treatment. Spot On Dewormer starts working almost immediately and is 100% effective at controlling the most common worms affective cats and kittens. There is no permanent treatment for worms. Veterinarians recommend that weaned kittens and adult cats be wormed every 3 months as a routine measure. It is also important to remove sources of possible re-infestation such as fleas and mice. For cats and weaned kittens weighing more than 1kg.