Healthy kittens should be wormed with a preparation recommended by your vet when they reach 5 weeks old. Thereafter they should be wormed as advised by your vet until they reach 6 months old and are wormed routinely as adults.
Sick kittens or kittens under 3 weeks old should only be wormed under veterinary supervision e.g. if they have a severe worm burden which is compromising their health and growth.
Before each dosing the kittens should be accurately weighed, since too little wormer will be ineffective and too much may cause illness. In many kittens the worms cause no clinical signs. In others they can result in poor body condition, soft or bloody stools, loss of appetite, pot-belly and weight loss.
Some worms can be transmitted through the stools of infected cats, while others are carried by fleas. As well as worming, good hygiene and flea control are essential.